(Radiographics. 2001;21:491-506.)
© RSNA, 2001
Invasive Procedures in the Female Pelvis: Value of Transabdominal, Endovaginal, and Endorectal US Guidance1
Kathleen A. Scanlan, MD,
Pamela A. Propeck, MD and
Fred T. Lee, Jr, MD
1 From Salem Radiology Consultants, 2925 Ryan Dr SE, Salem, OR 97301 (K.A.S.); and the Department of Radiology, University of Wisconsin Hospital and Clinics, Madison (P.A.P., F.T.L.). Recipient of a Certificate of Merit award for a scientific exhibit at the 1999 RSNA scientific assembly. Received April 5, 2000; revision requested May 19 and received December 5; accepted December 11. Address correspondence to K.A.S. (e-mail: kscanlan@wvi.com).
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Abstract
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Transabdominal, endovaginal, and endorectal ultrasonographic (US) guidance is indispensable for a multitude of invasive procedures in the female pelvis. Transabdominal uterine US performed with a fluid-filled bladder is appropriate and convenient for guidance of difficult dilation and curettage procedures. Transabdominal intraoperative US can be employed to guide several procedures for which the more expensive intraoperative hysteroscopic procedure is now used. Aspiration of symptomatic ovarian cysts that appear benign at US with an endovaginally guided small-gauge needle is simple and effective. Simple noninfected pelvic fluid collections may be aspirated transvaginally for both diagnosis and therapy by using endovaginal guidance. Endovaginal US demonstrates the anatomic relationships of a pelvic abscess to adjacent structures, allowing safe access for transvaginal drainage. By using an endovaginal transducer with a needle guide, cervical and vaginal cuff masses may be easily sampled. An obstructed uterus may be accessed by puncturing obstructive tissue with a trocar-containing needle guided by an endorectal probe. US guidance for placement of a central brachytherapy tandem is performed via the abdominal approach after the bladder has been distended with sterile water. Endorectal US transducers may be effectively used to guide placement of interstitial brachytherapy needles in pelvic soft-tissue masses.
Index Terms: Genitourinary system, interventional procedures, 85.126 • Genitourinary system, therapeutic radiology, 85.452 • Pelvic organs, interventional procedures, 85.126 • Pelvic organs, therapeutic radiology, 85.452 • Ultrasound (US), guidance, 85.1298
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Introduction
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Transabdominal, endovaginal, and endorectal ultrasonographic (US) guidance is invaluable in a wide array of invasive procedures in the female pelvis. The demand for these services has increased with the realization that many procedures can be performed more rapidly and safely by using imaging guidance and avoiding ionizing radiation, a concern in the premenopausal patient. More invasive procedures can often be avoided and complications reduced, decreasing the cost of therapy. US offers the unique advantages of portability, immediate availability, and flexibility owing in part to the wide range of transducers now available. The portability of modern US equipment makes it feasible to provide guidance in virtually any setting, including the US suite, operating room, patient examination room, and radiation therapy suite.
We assessed the use and effectiveness of US guidance of these procedures in our gynecologic patient populations with benign or malignant disease. The results of all bedside or intraoperative US examinations of the female pelvis performed between January 1997 and March 4, 1999, were reviewed. The purpose, success, and type of guidance for each intervention were evaluated. A total of 87 bedside or intraoperative US examinations of the female pelvis were performed in this interval. Most of these examinations were performed to provide guidance for interventional procedures (n = 67).
The procedures performed were as follows: transabdominal guidance (rarely combined with endorectal guidance) for placement of instruments in the difficult to access endometrial cavity (retroflexion, anatomic distortion) for purposes of drainage, tissue sampling, and assessing completion of evacuation (n = 23); transabdominally guided intraoperative US hysterography for diagnosis and resection guidance for malignant endometrial polyps (n = 1); transabdominal guidance for placement of endocavitary brachytherapy tandems for cervical carcinoma (n = 33), endometrial carcinoma (n = 12), cervical sarcoma (n =1), and endometrial sarcoma (n = 1); endovaginal guidance for drainage of symptomatic ovarian cysts (n = 1); endovaginal guidance for aspiration of pelvic fluid collections (n = 1); endovaginal drainage tube placement for a tubo-ovarian abscess refractive to antibiotic therapy (n = 1); endovaginal US (performed with an attachable biopsy guide) for sampling of masses in or near the cervix, vaginal fornices, or vaginal cuff (n = 3); endorectal guidance in conjunction with coaxial needle and J-wire exchange for obstructed endometrial cavity access with subsequent drainage, tissue sampling, or placement of a radiation therapy tandem (n = 5); and endorectal guidance for placement of interstitial treatment needles for advanced cervical carcinoma (n = 3) and advanced vaginal carcinoma (n = 2).
In this article, we describe and illustrate a variety of techniques used for diagnosis and therapy in the female pelvis that involve US guidance performed with the transabdominal, endovaginal, and endorectal approaches.
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Intraoperative Uterine US
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Indications
The most frequent indication for intraoperative US is a difficult dilation and curettage procedure (1). This procedure may be rendered problematic by extreme flexion or version of the uterus, congenital anomalies, vaginal or cervical os stenosis, and distortion of cervical and uterine anatomy by prior surgery or radiation therapy. A uterus containing an embryo or fetus may be particularly prone to perforation because of progesterone effect on the thinned myometrium. Standard gynecologic instruments including the curet, polyp forceps, and hysteroscope can be guided. The use of transabdominal US as an adjunct to uterine interventions was described by Hunter et al in 1989 (2). Guidance for uterine procedures by using an endorectal probe was described by Fleischer et al in 1990 (3). Although endorectal US provides exquisite detail of the cervix and uterus, it is somewhat more unwieldy to perform, requiring the radiologist to stand alongside the gynecologic surgeon in a relatively small working space with the patient in the dorsal lithotomy position.
Technique
We have found transabdominal uterine US performed with a fluid-filled bladder appropriate and convenient for most dilation and curettage guidance procedures. With close communication be-tween the gynecologist and the radiologist, a continuously monitored path between the cervix and the endometrial cavity allows the gynecologist to safely pass the instrument of choice. Directed sampling is possible by guiding the gynecologic surgeon to any specific focal area of abnormality detected with US (Fig 1). The progress of a dilation and curettage procedure can be monitored,and the thoroughness of uterine evacuation can be assessed (Fig 2). If scant tissue is obtained from the dilation and curettage, US hysterography may demonstrate a reason for the failure to obtain tissue, such as a mobile polyp or polypoid carcinoma.
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Figure 1a. Directed sampling in a 25-year-old woman who experienced a spontaneous abortion 5 months earlier and who underwent dilation and curettage. She had persistent bleeding and low levels of human chorionic gonadotropin, which were treated with systemic methotrexate therapy. The human chorionic gonadotropin level returned to zero, but persistent spotting led to performance of pelvic US. (a) Longitudinal transabdominal US scan of the uterus shows an approximately 2-cm-diameter, echogenic, shadowing focus (arrow) in the right side of the uterine fundus. (b) Intraoperative longitudinal transabdominal US scan shows a curet (arrowheads) directed toward the abnormal focus. (c, d) Longitudinal transabdominal US scans show the abnormal focus (arrow) after sampling and postcurettage air bubbles (arrowheads) in the arcuate veins. Histologic analysis demonstrated benign, hyalinized, calcified placental tissue.
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Figure 1b. Directed sampling in a 25-year-old woman who experienced a spontaneous abortion 5 months earlier and who underwent dilation and curettage. She had persistent bleeding and low levels of human chorionic gonadotropin, which were treated with systemic methotrexate therapy. The human chorionic gonadotropin level returned to zero, but persistent spotting led to performance of pelvic US. (a) Longitudinal transabdominal US scan of the uterus shows an approximately 2-cm-diameter, echogenic, shadowing focus (arrow) in the right side of the uterine fundus. (b) Intraoperative longitudinal transabdominal US scan shows a curet (arrowheads) directed toward the abnormal focus. (c, d) Longitudinal transabdominal US scans show the abnormal focus (arrow) after sampling and postcurettage air bubbles (arrowheads) in the arcuate veins. Histologic analysis demonstrated benign, hyalinized, calcified placental tissue.
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Figure 1c. Directed sampling in a 25-year-old woman who experienced a spontaneous abortion 5 months earlier and who underwent dilation and curettage. She had persistent bleeding and low levels of human chorionic gonadotropin, which were treated with systemic methotrexate therapy. The human chorionic gonadotropin level returned to zero, but persistent spotting led to performance of pelvic US. (a) Longitudinal transabdominal US scan of the uterus shows an approximately 2-cm-diameter, echogenic, shadowing focus (arrow) in the right side of the uterine fundus. (b) Intraoperative longitudinal transabdominal US scan shows a curet (arrowheads) directed toward the abnormal focus. (c, d) Longitudinal transabdominal US scans show the abnormal focus (arrow) after sampling and postcurettage air bubbles (arrowheads) in the arcuate veins. Histologic analysis demonstrated benign, hyalinized, calcified placental tissue.
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Figure 1d. Directed sampling in a 25-year-old woman who experienced a spontaneous abortion 5 months earlier and who underwent dilation and curettage. She had persistent bleeding and low levels of human chorionic gonadotropin, which were treated with systemic methotrexate therapy. The human chorionic gonadotropin level returned to zero, but persistent spotting led to performance of pelvic US. (a) Longitudinal transabdominal US scan of the uterus shows an approximately 2-cm-diameter, echogenic, shadowing focus (arrow) in the right side of the uterine fundus. (b) Intraoperative longitudinal transabdominal US scan shows a curet (arrowheads) directed toward the abnormal focus. (c, d) Longitudinal transabdominal US scans show the abnormal focus (arrow) after sampling and postcurettage air bubbles (arrowheads) in the arcuate veins. Histologic analysis demonstrated benign, hyalinized, calcified placental tissue.
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Figure 2a. Assessment of uterine evacuation in a 19-year-old woman who sustained a missed abortion and who had a possible molar pregnancy. The human chorionic gonadotropin level was elevated. (a) Longitudinal transabdominal US scan of the uterus obtained during dilation and curettage shows a suction curet within the enlarged uterus (arrowheads). Sharp curettage followed. (b) Longitudinal transabdominal US scan obtained at the conclusion of the procedure shows nearly complete emptying of the uterus. Note the speculum within the vaginal fornix (arrow). Histologic analysis demonstrated decidual endometrium and small and hydropic chorionic villi. The human chorionic gonadotropin level returned to zero.
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Figure 2b. Assessment of uterine evacuation in a 19-year-old woman who sustained a missed abortion and who had a possible molar pregnancy. The human chorionic gonadotropin level was elevated. (a) Longitudinal transabdominal US scan of the uterus obtained during dilation and curettage shows a suction curet within the enlarged uterus (arrowheads). Sharp curettage followed. (b) Longitudinal transabdominal US scan obtained at the conclusion of the procedure shows nearly complete emptying of the uterus. Note the speculum within the vaginal fornix (arrow). Histologic analysis demonstrated decidual endometrium and small and hydropic chorionic villi. The human chorionic gonadotropin level returned to zero.
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Intraoperative US Hysterography
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Indications
In the setting of a thickened endometrial stripe with inability to obtain adequate tissue, intraoperative US hysterography can provide critical information for determining whether an endometrial abnormality is focal or global.
Technique
The procedure is performed in a similar fashion to in-office US hysterography. A small amount of sterile saline solution is administered into the endometrial space via a small catheter placed through the cervical os. The endometrial cavity is distended until endometrial detail is appreciated. Endovaginal imaging may be initially performed for diagnosis followed by transabdominal or endorectal US to guide interventions. In this fashion, the gynecologic surgeon can obtain real-time information to direct biopsy forceps, polypectomy forceps, or a polypectomy snare to a focal intrauterine abnormality (Fig 3). A small catheter may be kept in place to replace saline solution as needed. This technique was used by Lindheim et al (4) in evaluation and biopsy of the endometrium in seven cases. Uterine access was obtained with a 9-F cervical access catheter, fluid was administered, and loop or finger graspers were passed through the cervical access catheter. The authors were successful in resecting endometrial lesions in about half of the cases. Intraoperative US has the potential to guide several procedures for which the more expensive intraoperative hysteroscopic procedure is now used. With further refinement, intraoperative US could provide a cost-effective alternative to hysteroscopy in select cases.
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Figure 3a. Identification of endometrial polyps in a 64-year-old woman with postmenopausal bleeding who had been receiving unopposed estrogen therapy for 8 years. Endometrial biopsy could not be performed in the office because of a stenotic os. Intraoperatively, a uterine sound had been placed to 15 cm, and US was performed to evaluate for possible perforation. (a) Longitudinal US scan of the uterus shows a thickened endometrial stripe (arrowheads) and a perforation track (arrows). The sound had been removed when the image was obtained. (b) Longitudinal transabdominal US scan shows a Pipelle endometrial biopsy device (Unimar, Shelton, Conn) (arrowheads) in the endometrial space; however, no tissue was obtained. Curettage yielded only minimal tissue. (c) Longitudinal US hysterogram obtained with a balloon-tip catheter shows endometrial polyps (arrowheads). With transabdominal US guidance, polyp forceps were directed to the abnormality and the polyps were removed in fragments. The uterine cavity was then curetted. Histologic analysis demonstrated grade 1 adenocarcinoma of the endometrium (according to the staging system of the International Federation of Gynecology and Obstetrics).
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Figure 3b. Identification of endometrial polyps in a 64-year-old woman with postmenopausal bleeding who had been receiving unopposed estrogen therapy for 8 years. Endometrial biopsy could not be performed in the office because of a stenotic os. Intraoperatively, a uterine sound had been placed to 15 cm, and US was performed to evaluate for possible perforation. (a) Longitudinal US scan of the uterus shows a thickened endometrial stripe (arrowheads) and a perforation track (arrows). The sound had been removed when the image was obtained. (b) Longitudinal transabdominal US scan shows a Pipelle endometrial biopsy device (Unimar, Shelton, Conn) (arrowheads) in the endometrial space; however, no tissue was obtained. Curettage yielded only minimal tissue. (c) Longitudinal US hysterogram obtained with a balloon-tip catheter shows endometrial polyps (arrowheads). With transabdominal US guidance, polyp forceps were directed to the abnormality and the polyps were removed in fragments. The uterine cavity was then curetted. Histologic analysis demonstrated grade 1 adenocarcinoma of the endometrium (according to the staging system of the International Federation of Gynecology and Obstetrics).
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Figure 3c. Identification of endometrial polyps in a 64-year-old woman with postmenopausal bleeding who had been receiving unopposed estrogen therapy for 8 years. Endometrial biopsy could not be performed in the office because of a stenotic os. Intraoperatively, a uterine sound had been placed to 15 cm, and US was performed to evaluate for possible perforation. (a) Longitudinal US scan of the uterus shows a thickened endometrial stripe (arrowheads) and a perforation track (arrows). The sound had been removed when the image was obtained. (b) Longitudinal transabdominal US scan shows a Pipelle endometrial biopsy device (Unimar, Shelton, Conn) (arrowheads) in the endometrial space; however, no tissue was obtained. Curettage yielded only minimal tissue. (c) Longitudinal US hysterogram obtained with a balloon-tip catheter shows endometrial polyps (arrowheads). With transabdominal US guidance, polyp forceps were directed to the abnormality and the polyps were removed in fragments. The uterine cavity was then curetted. Histologic analysis demonstrated grade 1 adenocarcinoma of the endometrium (according to the staging system of the International Federation of Gynecology and Obstetrics).
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US-guided Aspiration of Benign-appearing Ovarian Cysts
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The value and risks of endovaginal US guidance of ovarian cyst aspiration remain a topic of debate. Aspiration of symptomatic cysts that appear benign at US with an endovaginally guided small-gauge needle (20 or 22 gauge) is simple and effective, often alleviating pain rapidly and requiring little if any sedation or analgesia. Opponents of the technique contend that the recurrence rate is high, there is potential for seeding malignant cells along the needle track, and the risk of sampling error could delay diagnosis of an occult malignancy. The classic therapy for persistent symptomatic cysts has been surgical extirpation by means of laparoscopy or open laparotomy. Both of these procedures have the risks associated withanesthesia and the risks of bleeding, bowel perforation, infection, and adhesion formation with possible compromise of fertility. Adhesions, pregnancy, or medical risk factors may limit surgical therapy.
Although there is little information in the literature to verify the seeding of a fine-needle track with malignant cells, there is general agreement that fine-needle aspiration of cysts with malignant features has limited value. A definitive surgical procedure is usually indicated whether the cytologic results are positive or negative. In a patient with a preexisting diagnosis of ovarian carcinoma and a new pelvic mass, fine-needle aspiration ofthe mass can spare the patient an additional surgical procedure. In patients who are poor surgical candidates, fine-needle aspiration of an indeterminate ovarian mass may aid in management decisions.
Indications
There is less debate over the aspiration of simple ovarian cysts in pre- and perimenopausal women in whom the risk of malignancy is low. US criteria for benign ovarian masses are well-established and include completely cystic lesions, cysts with thin (<3 mm) and smooth septa, and cysts with diffuse low-level echoes or an echo pattern suggestive of hemorrhagic cyst, in all of which internal vascularity is absent on color Doppler images. Cysts with features pathognomonic of mature cystic teratoma (hyperechoic mural plug, fat-fluid level, hair matrix) should not be aspirated, since these require surgical excision. Pre- and perimenopausal women with persistent, painful cysts that have no US features of malignancy are candidates for aspiration. Patients with acute pain in the proper clinical setting should be evaluated for ovarian torsion prior to aspiration (5). Many authors contend that postmenopausal women withunilocular cysts less than 5 cm in diameter are also candidates for aspiration because they are at minimal risk for malignancy.
Technique
Endovaginally guided aspiration must be preceded by a diagnostic endovaginal study to care-fully evaluate the features of the cyst and determine the shortest, safest needle route, avoiding the intestine, the bladder, and vascular structures. Color Doppler examination aids in planning. A local anesthetic is not normally administered, but a mild oral sedative may ease the patient’s anxiety. Most cysts occur close to the vaginal fornices. Once the needle trajectory has been determined and the vaginal vault and cervix have been prepared with povidone-iodine, the endovaginal transducer, with a sterile sheath and needle guide, is applied firmly against the vaginal fornix. With needle-guide software activated, a 20–25-cm-long needle (20 or 22 gauge) is advanced through the vaginal wall with a short, quick thrust (Fig 4). This technique minimizes difficulty due to tenting of the elastic vaginal tissues. Pressure applied to the lower abdomen during the procedure may help stabilize a mobile cyst. Care should be taken to ensure that the central stylet does not become dislodged. Fluid should be sent for cytologic analysis to confirm a benign cellular or acellular content. Complete aspiration decreases the frequency of recurrence.
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Figure 4a. Ovarian cyst aspiration in a 30-year-old woman with acute lower abdominal pain. She was a poor surgical candidate, having undergone multiple prior bowel surgeries. Computed tomography (CT) was performed to evaluate for possible appendicitis or diverticulitis. (a) CT scan of the pelvis shows diffusely dilated small intestine and an 8-cm-diameter, low-attenuation right adnexal mass (arrowheads). (b) Longitudinal endovaginal color Doppler image shows a right ovarian cyst with fine, low-level internal echoes. The cyst was thought to be unilocular and avascular. Arrow = adjacent vessels. (c) Photograph shows a condom-sheathed endovaginal probe with a needle guide and a 20-cm-long, 20-gauge Chiba needle. A second condom may be added over the needle guide. (d) Longitudinal endovaginal US scan shows the needle within the cyst. Note the adjacent intestine (arrows). (e) Postaspiration longitudinal US scan shows that the cyst wall has collapsed (arrowheads). A second adjacent locule became apparent after aspiration (arrows). Continuing pain led to laparotomy and right oophorectomy. Biopsy of one cyst wall showed a serous cystadenoma; biopsy of the other cyst wall revealed a benign cyst. The fluid contained reactive mesothelial cells.
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Figure 4b. Ovarian cyst aspiration in a 30-year-old woman with acute lower abdominal pain. She was a poor surgical candidate, having undergone multiple prior bowel surgeries. Computed tomography (CT) was performed to evaluate for possible appendicitis or diverticulitis. (a) CT scan of the pelvis shows diffusely dilated small intestine and an 8-cm-diameter, low-attenuation right adnexal mass (arrowheads). (b) Longitudinal endovaginal color Doppler image shows a right ovarian cyst with fine, low-level internal echoes. The cyst was thought to be unilocular and avascular. Arrow = adjacent vessels. (c) Photograph shows a condom-sheathed endovaginal probe with a needle guide and a 20-cm-long, 20-gauge Chiba needle. A second condom may be added over the needle guide. (d) Longitudinal endovaginal US scan shows the needle within the cyst. Note the adjacent intestine (arrows). (e) Postaspiration longitudinal US scan shows that the cyst wall has collapsed (arrowheads). A second adjacent locule became apparent after aspiration (arrows). Continuing pain led to laparotomy and right oophorectomy. Biopsy of one cyst wall showed a serous cystadenoma; biopsy of the other cyst wall revealed a benign cyst. The fluid contained reactive mesothelial cells.
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Figure 4c. Ovarian cyst aspiration in a 30-year-old woman with acute lower abdominal pain. She was a poor surgical candidate, having undergone multiple prior bowel surgeries. Computed tomography (CT) was performed to evaluate for possible appendicitis or diverticulitis. (a) CT scan of the pelvis shows diffusely dilated small intestine and an 8-cm-diameter, low-attenuation right adnexal mass (arrowheads). (b) Longitudinal endovaginal color Doppler image shows a right ovarian cyst with fine, low-level internal echoes. The cyst was thought to be unilocular and avascular. Arrow = adjacent vessels. (c) Photograph shows a condom-sheathed endovaginal probe with a needle guide and a 20-cm-long, 20-gauge Chiba needle. A second condom may be added over the needle guide. (d) Longitudinal endovaginal US scan shows the needle within the cyst. Note the adjacent intestine (arrows). (e) Postaspiration longitudinal US scan shows that the cyst wall has collapsed (arrowheads). A second adjacent locule became apparent after aspiration (arrows). Continuing pain led to laparotomy and right oophorectomy. Biopsy of one cyst wall showed a serous cystadenoma; biopsy of the other cyst wall revealed a benign cyst. The fluid contained reactive mesothelial cells.
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Figure 4d. Ovarian cyst aspiration in a 30-year-old woman with acute lower abdominal pain. She was a poor surgical candidate, having undergone multiple prior bowel surgeries. Computed tomography (CT) was performed to evaluate for possible appendicitis or diverticulitis. (a) CT scan of the pelvis shows diffusely dilated small intestine and an 8-cm-diameter, low-attenuation right adnexal mass (arrowheads). (b) Longitudinal endovaginal color Doppler image shows a right ovarian cyst with fine, low-level internal echoes. The cyst was thought to be unilocular and avascular. Arrow = adjacent vessels. (c) Photograph shows a condom-sheathed endovaginal probe with a needle guide and a 20-cm-long, 20-gauge Chiba needle. A second condom may be added over the needle guide. (d) Longitudinal endovaginal US scan shows the needle within the cyst. Note the adjacent intestine (arrows). (e) Postaspiration longitudinal US scan shows that the cyst wall has collapsed (arrowheads). A second adjacent locule became apparent after aspiration (arrows). Continuing pain led to laparotomy and right oophorectomy. Biopsy of one cyst wall showed a serous cystadenoma; biopsy of the other cyst wall revealed a benign cyst. The fluid contained reactive mesothelial cells.
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Figure 4e. Ovarian cyst aspiration in a 30-year-old woman with acute lower abdominal pain. She was a poor surgical candidate, having undergone multiple prior bowel surgeries. Computed tomography (CT) was performed to evaluate for possible appendicitis or diverticulitis. (a) CT scan of the pelvis shows diffusely dilated small intestine and an 8-cm-diameter, low-attenuation right adnexal mass (arrowheads). (b) Longitudinal endovaginal color Doppler image shows a right ovarian cyst with fine, low-level internal echoes. The cyst was thought to be unilocular and avascular. Arrow = adjacent vessels. (c) Photograph shows a condom-sheathed endovaginal probe with a needle guide and a 20-cm-long, 20-gauge Chiba needle. A second condom may be added over the needle guide. (d) Longitudinal endovaginal US scan shows the needle within the cyst. Note the adjacent intestine (arrows). (e) Postaspiration longitudinal US scan shows that the cyst wall has collapsed (arrowheads). A second adjacent locule became apparent after aspiration (arrows). Continuing pain led to laparotomy and right oophorectomy. Biopsy of one cyst wall showed a serous cystadenoma; biopsy of the other cyst wall revealed a benign cyst. The fluid contained reactive mesothelial cells.
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Troiano and Taylor (6) studied the outcomes in 32 cases of cysts (diameter, 3.1–19 cm) in pre- and postmenopausal women that appeared benign at US and that were endovaginally aspirated. The recurrence rate for nonendometriomas was 16.1%, and all cytologic diagnoses in this carefully preselected group were benign. A number of other studies (7)–(12) have confirmed that US-guided aspiration of simple ovarian cysts is a safe and effective alternative to surgery when strict selection criteria are used. Whether recurrent cysts with a benign cytologic diagnosis should be treated with reaspiration or surgical extirpation is open to debate.
Cysts with US features of endometrioma (diffuse low-level echoes) have been aspirated for both diagnosis and therapy, but therapeutic results have been disappointing, with relatively high recurrence rates. However, complete cyst drainage combined with suppressive hormonal therapy holds promise (6).
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US-guided Aspiration of Pelvic Fluid Collections
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Simple noninfected pelvic fluid collections may be aspirated transvaginally for both diagnosis and therapy by using endovaginal guidance. Many collections can be completely drained with aspiration alone without the need for drain placement (13).
Indications
Those collections amenable to drainage include loculated ascites, pseudocysts surrounding ventriculoperitoneal shunt tips, urinomas, resolving hematomas, lymphoceles, peritoneal inclusion cysts, and pancreatic pseudocysts or effusions (primarily in patients with pancreatic transplants). Pelvic collections may be difficult to access via other routes, since they are often closely surrounded by the intestine, the bladder, and adnexal structures. Alternative drainage routes such as the anterior abdominal, posterior transgluteal (through the greater sciatic foramen), and transrectal approaches are possible but may be more painful or require CT guidance. Aspiration via the latter routes usually requires conscious sedation and exposes the patient to higher risks, including bowel perforation and neurovascular injury.
Technique
A safe route from the vaginal vault to the collection is first established with endovaginal US evaluation. Virtually all collections can be reached with a 20–25-cm-long (20 or 22 gauge) needle. Most patients do not require conscious sedation for simple transvaginal aspirations. A local anesthetic is not normally required. A sharp thrust of the needle and firm transducer application to the vaginal fornix can help traverse the redundant and elastic vaginal tissue (Fig 5). When the returned aspirate is nonpurulent and serous or serosanguineous and the patient is afebrile, a drainage catheter is normally not needed. Most aspirates should be sent for Gram stain, culture and sensitivity, and other chemical tests appropriate to the patient’s clinical history (eg, amylase level in a patient with a pancreatic transplant, creatinine for possible urinoma).
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Figure 5a. Aspiration of a pelvic fluid collection in a 37-year-old woman who had undergone an extensive myomectomy complicated by postoperative hemorrhage that required reexploration. Pelvic US was performed several months later in preparation for ovulation induction. (a, b) Longitudinal endovaginal US scans of the pelvis show a multiloculated clear fluid collection in the cul-de-sac and posterior to the uterus, encompassing the left ovary (arrowheads in b). The diagnosis of peritoneal inclusion cyst was favored. (c, d) Longitudinal endovaginal US scans show the cul-de-sac. A 20-cm-long, 23-gauge Chiba needle was advanced through the needle guide, and clear, straw-colored fluid was aspirated. Note the avoidance of the rectosigmoid (arrowheads in c). Vaginal wall tenting (arrow in d) can be avoided by using a quick thrust and firm transducer pressure on the vaginal fornix. Results of cytologic analysis were negative for malignancy (chronic inflammation and reactive mesothelial cells).
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Figure 5b. Aspiration of a pelvic fluid collection in a 37-year-old woman who had undergone an extensive myomectomy complicated by postoperative hemorrhage that required reexploration. Pelvic US was performed several months later in preparation for ovulation induction. (a, b) Longitudinal endovaginal US scans of the pelvis show a multiloculated clear fluid collection in the cul-de-sac and posterior to the uterus, encompassing the left ovary (arrowheads in b). The diagnosis of peritoneal inclusion cyst was favored. (c, d) Longitudinal endovaginal US scans show the cul-de-sac. A 20-cm-long, 23-gauge Chiba needle was advanced through the needle guide, and clear, straw-colored fluid was aspirated. Note the avoidance of the rectosigmoid (arrowheads in c). Vaginal wall tenting (arrow in d) can be avoided by using a quick thrust and firm transducer pressure on the vaginal fornix. Results of cytologic analysis were negative for malignancy (chronic inflammation and reactive mesothelial cells).
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Figure 5c. Aspiration of a pelvic fluid collection in a 37-year-old woman who had undergone an extensive myomectomy complicated by postoperative hemorrhage that required reexploration. Pelvic US was performed several months later in preparation for ovulation induction. (a, b) Longitudinal endovaginal US scans of the pelvis show a multiloculated clear fluid collection in the cul-de-sac and posterior to the uterus, encompassing the left ovary (arrowheads in b). The diagnosis of peritoneal inclusion cyst was favored. (c, d) Longitudinal endovaginal US scans show the cul-de-sac. A 20-cm-long, 23-gauge Chiba needle was advanced through the needle guide, and clear, straw-colored fluid was aspirated. Note the avoidance of the rectosigmoid (arrowheads in c). Vaginal wall tenting (arrow in d) can be avoided by using a quick thrust and firm transducer pressure on the vaginal fornix. Results of cytologic analysis were negative for malignancy (chronic inflammation and reactive mesothelial cells).
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Figure 5d. Aspiration of a pelvic fluid collection in a 37-year-old woman who had undergone an extensive myomectomy complicated by postoperative hemorrhage that required reexploration. Pelvic US was performed several months later in preparation for ovulation induction. (a, b) Longitudinal endovaginal US scans of the pelvis show a multiloculated clear fluid collection in the cul-de-sac and posterior to the uterus, encompassing the left ovary (arrowheads in b). The diagnosis of peritoneal inclusion cyst was favored. (c, d) Longitudinal endovaginal US scans show the cul-de-sac. A 20-cm-long, 23-gauge Chiba needle was advanced through the needle guide, and clear, straw-colored fluid was aspirated. Note the avoidance of the rectosigmoid (arrowheads in c). Vaginal wall tenting (arrow in d) can be avoided by using a quick thrust and firm transducer pressure on the vaginal fornix. Results of cytologic analysis were negative for malignancy (chronic inflammation and reactive mesothelial cells).
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Cytologic examination of the fluid should be performed to evaluate for the unlikely possibility of unsuspected cystic malignancy of ovarian or peritoneal origin. If aspiration is limited to those collections that have no US criteria of ovarian malignancy, the risk of a false-negative aspirate is extremely low. On the basis of the Gram stain results, the appearance of the aspirated fluid, and the clinical condition of the patient, the procedure can be converted into a drain placement procedure.
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US-guided Drainage of Pelvic Abscesses
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Indications
Abscesses within the female pelvis are frequently located close to the apex of the vaginal vault. Tubo-ovarian abscesses as well as appendiceal, diverticular, inflammatory bowel, and peritonitis-related collections often form loculi in the pelvis. Gynecologic surgeons have long drained pelvic abscesses that bulge into the vagina with simple incision (posterior colpotomy). This procedure can be updated and enhanced by using US guidance to determine the anatomic relationships of the abscess to the vaginal vault and adjacent structures (rectum, bladder, uterus, and small intestine), allowing safe access for transvaginal drainage. For many pelvic collections, this approach is the safest and least painful. Multiple authors have described a variety of techniques for achieving this end (13)–(17).
Technique
Two endovaginally guided techniques have been advocated. The Seldinger technique involves stepwise placement of a needle and a J-wire, fol-lowed by dilation and placement of a self-retaining drain (13)–(16). The second approach involves single-step placement of a drainage catheter with a stiffened stylet (trocar technique) (17). When a drain is placed, conscious sedation is normally needed.
The Seldinger technique is performed as follows: A condom-sheathed transducer with a needle guide is introduced into the vagina after preparation of the cervix, vagina, and vaginal fornices with povidone-iodine. Firm probe pressure against the vaginal fornix combined with a quick needle thrust facilitates puncture. After the initial needle placement, the needle is exchanged for a floppy-tip wire, which is coiled in the abscess cavity (Fig 6). The endovaginal probe is removed,and then progressive dilation can be performed. It may be helpful to place a speculum and make a small nick with a long-handled blade at the site of wire entry, facilitating entry of the dilators and ultimately the drain over the wire. The nick should be made in the coronal plane to minimize the chance of injury to vascular structures. If necessary, the cervix may be moved with a sponge stick to allow visualization of the vaginal fornices. Once progressive dilation of the track is completed, a drain (usually 6–12-F self-retaining) is placed over the wire and secured, and the wire is removed.
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Figure 6a. Drainage of pelvic abscesses in a young woman with fever, pelvic pain, and positive cultures for Chlamydia. Antibiotic therapy was instituted. (a) Transverse endovaginal US scan shows bilateral adnexal fluid collections with internal echoes, which are highly suggestive of tubo-ovarian abscesses. (b) Longitudinal endovaginal US scan of the left adnexal area shows a residual collection that was unresponsive to antibiotic therapy. The patient remained systemically ill. (c) Longitudinal endovaginal US scan shows a needle tip (arrow) advanced into the collection across the vaginal fornix. (d) Longitudinal endovaginal US scan shows a wire (arrowheads) coiled in the abscess cavity. The patient became afebrile within 24 hours of drain placement and went home 2 days later. (e) Photograph shows a 6-F self-retaining drain.
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Figure 6b. Drainage of pelvic abscesses in a young woman with fever, pelvic pain, and positive cultures for Chlamydia. Antibiotic therapy was instituted. (a) Transverse endovaginal US scan shows bilateral adnexal fluid collections with internal echoes, which are highly suggestive of tubo-ovarian abscesses. (b) Longitudinal endovaginal US scan of the left adnexal area shows a residual collection that was unresponsive to antibiotic therapy. The patient remained systemically ill. (c) Longitudinal endovaginal US scan shows a needle tip (arrow) advanced into the collection across the vaginal fornix. (d) Longitudinal endovaginal US scan shows a wire (arrowheads) coiled in the abscess cavity. The patient became afebrile within 24 hours of drain placement and went home 2 days later. (e) Photograph shows a 6-F self-retaining drain.
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Figure 6c. Drainage of pelvic abscesses in a young woman with fever, pelvic pain, and positive cultures for Chlamydia. Antibiotic therapy was instituted. (a) Transverse endovaginal US scan shows bilateral adnexal fluid collections with internal echoes, which are highly suggestive of tubo-ovarian abscesses. (b) Longitudinal endovaginal US scan of the left adnexal area shows a residual collection that was unresponsive to antibiotic therapy. The patient remained systemically ill. (c) Longitudinal endovaginal US scan shows a needle tip (arrow) advanced into the collection across the vaginal fornix. (d) Longitudinal endovaginal US scan shows a wire (arrowheads) coiled in the abscess cavity. The patient became afebrile within 24 hours of drain placement and went home 2 days later. (e) Photograph shows a 6-F self-retaining drain.
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Figure 6d. Drainage of pelvic abscesses in a young woman with fever, pelvic pain, and positive cultures for Chlamydia. Antibiotic therapy was instituted. (a) Transverse endovaginal US scan shows bilateral adnexal fluid collections with internal echoes, which are highly suggestive of tubo-ovarian abscesses. (b) Longitudinal endovaginal US scan of the left adnexal area shows a residual collection that was unresponsive to antibiotic therapy. The patient remained systemically ill. (c) Longitudinal endovaginal US scan shows a needle tip (arrow) advanced into the collection across the vaginal fornix. (d) Longitudinal endovaginal US scan shows a wire (arrowheads) coiled in the abscess cavity. The patient became afebrile within 24 hours of drain placement and went home 2 days later. (e) Photograph shows a 6-F self-retaining drain.
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Figure 6e. Drainage of pelvic abscesses in a young woman with fever, pelvic pain, and positive cultures for Chlamydia. Antibiotic therapy was instituted. (a) Transverse endovaginal US scan shows bilateral adnexal fluid collections with internal echoes, which are highly suggestive of tubo-ovarian abscesses. (b) Longitudinal endovaginal US scan of the left adnexal area shows a residual collection that was unresponsive to antibiotic therapy. The patient remained systemically ill. (c) Longitudinal endovaginal US scan shows a needle tip (arrow) advanced into the collection across the vaginal fornix. (d) Longitudinal endovaginal US scan shows a wire (arrowheads) coiled in the abscess cavity. The patient became afebrile within 24 hours of drain placement and went home 2 days later. (e) Photograph shows a 6-F self-retaining drain.
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Because some radiologists have encountered problems with the dilator or drain buckling when it is passed through the vaginal wall, some authors have advocated a one-step procedure that involves use of a 6–8-F catheter with a stylet (trocar method). McGahan et al (17) described a technique whereby a 6.7-F McGahan drainage catheter (Cook, Bloomington, Ind) is mounted into the needle-guide groove of the vaginal transducer and kept in place with small rubber bands and finger pressure on the catheter by the radiologist. After puncture of the fluid collection, the catheter is advanced, then coiled and secured if purulent material is returned. Opponents believe that this approach does not allow the same degree of control as the Seldinger technique and could lead to inadvertent injury.
Although some radiologists perform lavage of the abscess cavity with saline solution or half-strength povidone-iodine in conjunction with drain placement, others advocate simple aspiration followed by lavage and systemic antibiotic therapy without placement of a self-retaining catheter, claiming clinical success equal to that of catheter placement with improved patient comfort (13),(15). Further study is needed to determine the optimal management protocol.
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US-guided Biopsy of Cervical and Vaginal Cuff Masses
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Indications
Persistent or recurrent gynecologic malignancies may manifest as a mass at the cervix or vaginal cuff. The cervix and vagina may be distorted byradiation change or vaginal agglutination, causing further difficulty in assessing anatomy. Radiation-damaged intestine may lie close to or adhere to the vaginal cuff. These vaginal apex masses may be easily visualized with endovaginal US and assessed for size and proximity to bowel loops and the bladder.
Technique
By using an endovaginal transducer with a needle guide, these masses may be easily sampled with an automated biopsy gun fitted with a long (20 cm) needle (Fig 7). Multiple 18-gauge cores can be obtained, and if necessary, bleeding can be controlled with direct pressure, a styptic pencil, or vaginal packing. In addition, a cytologic specimen may be obtained with a long 20- or 22-gauge needle by using multiple short-path thrusts into the abnormal tissue. Immediate results can often be obtained if there is an on-site cytopathologist. We prefer to perform fine-needle aspiration initially and proceed to core biopsy for histologic analysis if the cytologic findings are nondiagnostic. Direct visualization during the biopsy allows avoidance of the intestine, the bladder, and vascular structures.
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Figure 7a. Biopsy of a cervical mass in a 32-year-old woman with a history of recent stage IB2 squamous cell carcinoma of the cervix (according to the staging system of the International Federation of Gynecology and Obstetrics). The carcinoma was diagnosed with cone biopsy performed with the loop electrocautery excision procedure and was treated with high-dose-rate intracavitary brachytherapy. The patient did well until approximately 6 months after treatment, when a new mass was identified in the cervix. (a) Longitudinal endovaginal US scan obtained with the biopsy-guide software activated shows the needle path to the hypoechoic cervical nodule (arrowheads). Note the proximity of the intestine (arrows) to the mass. (b) Longitudinal US scan shows a 20-cm-long, 18-gauge core needle with a 2.2-cm throw (arrow), which was used to obtain multiple samples from the mass. Histologic analysis demonstrated high-grade cervical carcinoma. (c) Sagittal magnetic resonance (MR) image shows the original cervical mass (arrowheads).
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Figure 7b. Biopsy of a cervical mass in a 32-year-old woman with a history of recent stage IB2 squamous cell carcinoma of the cervix (according to the staging system of the International Federation of Gynecology and Obstetrics). The carcinoma was diagnosed with cone biopsy performed with the loop electrocautery excision procedure and was treated with high-dose-rate intracavitary brachytherapy. The patient did well until approximately 6 months after treatment, when a new mass was identified in the cervix. (a) Longitudinal endovaginal US scan obtained with the biopsy-guide software activated shows the needle path to the hypoechoic cervical nodule (arrowheads). Note the proximity of the intestine (arrows) to the mass. (b) Longitudinal US scan shows a 20-cm-long, 18-gauge core needle with a 2.2-cm throw (arrow), which was used to obtain multiple samples from the mass. Histologic analysis demonstrated high-grade cervical carcinoma. (c) Sagittal magnetic resonance (MR) image shows the original cervical mass (arrowheads).
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Figure 7c. Biopsy of a cervical mass in a 32-year-old woman with a history of recent stage IB2 squamous cell carcinoma of the cervix (according to the staging system of the International Federation of Gynecology and Obstetrics). The carcinoma was diagnosed with cone biopsy performed with the loop electrocautery excision procedure and was treated with high-dose-rate intracavitary brachytherapy. The patient did well until approximately 6 months after treatment, when a new mass was identified in the cervix. (a) Longitudinal endovaginal US scan obtained with the biopsy-guide software activated shows the needle path to the hypoechoic cervical nodule (arrowheads). Note the proximity of the intestine (arrows) to the mass. (b) Longitudinal US scan shows a 20-cm-long, 18-gauge core needle with a 2.2-cm throw (arrow), which was used to obtain multiple samples from the mass. Histologic analysis demonstrated high-grade cervical carcinoma. (c) Sagittal magnetic resonance (MR) image shows the original cervical mass (arrowheads).
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US-guided Access to the Obstructed Uterus
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Indications
Most interventional gynecologic procedures require access to the endometrial cavity via the cervical os. Drainage of intrauterine fluid collections (hematometras, pyometras), biopsy of the endometrium with suction or curettage, hysteroscope placement (polyp removal, submucous fibroid resection, endometrial ablation), and placement of intrauterine tandems to deliver endocavitary brachytherapy are all precluded by a cervical os that cannot be traversed. The os may be distorted or stenosed from a neoplasm, surgery, or prior radiation therapy. Postmenopausal cervical stenosis may not allow access to the uterine cavity. Congenital uterine malformations may have an obstructive component with an abnormal cervix, congenital webs, or tissue blocks.
In many of these scenarios, access may be achieved by puncturing the central area of the cervix or obstructive tissue with a US-guided trocar-containing needle (18 gauge). Intrauterinefluid collections can thus be sampled and drained. Further access can be achieved by passing a floppy-tip wire through the needle and coiling it in the endometrial cavity. Progressive dilators and a dilator with a sheath may then be passed over the wire to create a channel for passage of a curet, hysteroscope, or radiation therapy tandem.
Technique
A convenient method for the radiologist to guide and perform this procedure is transrectal guid-ance with a biplane endorectal probe that has both linear and axial transducers. Because there may be a great deal of manipulation, conscious sedation may not be adequate and spinal or general anesthesia may be required. The cervix can be evaluated initially in the transverse plane, and the centrally placed needle puncture can be initiated at the proper x-y coordinate.
At this point, the cephalic progress of the needle tip can be monitored by switching to the linear component of the endorectal probe (Fig 8). Minor corrections in the anteroposterior angulation of the needle can be made until the tip is within the endometrial cavity. A small amount of saline solution may be injected through the needle if required to delineate the cavity. A wire is passed through the needle and coiled in the endometrial cavity, the access needle is removed, and dilators are passed over the wire. A nick made with a long-handled blade at the site of wire entry can ease initial passage of the dilators. Dilators up to 22 F (7.3 mm) are provided in the kit used at the University of Wisconsin (Cook) for this purpose (Fig 9). When an adequate track has been created, a sheath-covered dilator is placed, the inner dilator is removed, and the uterine instrument is passed through the sheath.
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Figure 8a. Uterine access in a 68-year-old woman with cervical os stenosis and postmenopausal bleeding. The initial needle puncture was performed from the cervix to the endometrial cavity with axial guidance. (a) Transverse US scan of the uterus shows the needle (arrows) and the margin of the uterus (arrowheads). After the needle tip was documented in the cavity, a wire was passed through the needle and coiled in the cavity. The exchange was monitored from the longitudinal approach. (b) Longitudinal endorectal US scan of the uterus shows the wire in the uterine cavity (arrows) and the anterior margin of the uterus (arrowheads). (c) Longitudinal endorectal US scan of the uterus obtained after wire access was secured shows progressive dilators (arrowheads) passed over the wire.
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Figure 8b. Uterine access in a 68-year-old woman with cervical os stenosis and postmenopausal bleeding. The initial needle puncture was performed from the cervix to the endometrial cavity with axial guidance. (a) Transverse US scan of the uterus shows the needle (arrows) and the margin of the uterus (arrowheads). After the needle tip was documented in the cavity, a wire was passed through the needle and coiled in the cavity. The exchange was monitored from the longitudinal approach. (b) Longitudinal endorectal US scan of the uterus shows the wire in the uterine cavity (arrows) and the anterior margin of the uterus (arrowheads). (c) Longitudinal endorectal US scan of the uterus obtained after wire access was secured shows progressive dilators (arrowheads) passed over the wire.
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Figure 8c. Uterine access in a 68-year-old woman with cervical os stenosis and postmenopausal bleeding. The initial needle puncture was performed from the cervix to the endometrial cavity with axial guidance. (a) Transverse US scan of the uterus shows the needle (arrows) and the margin of the uterus (arrowheads). After the needle tip was documented in the cavity, a wire was passed through the needle and coiled in the cavity. The exchange was monitored from the longitudinal approach. (b) Longitudinal endorectal US scan of the uterus shows the wire in the uterine cavity (arrows) and the anterior margin of the uterus (arrowheads). (c) Longitudinal endorectal US scan of the uterus obtained after wire access was secured shows progressive dilators (arrowheads) passed over the wire.
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US-guided Placement of Brachytherapy Devices
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The most commonly used and best-known form of radiation therapy is external-beam irradiation (teletherapy). Brachytherapy, in which radiation is delivered over a short distance, is used to treat many malignancies of the female pelvis, often in conjunction with external-beam irradiation. High-dose-rate brachytherapy permits delivery of relatively high doses in a shorter interval with sparing of normal tissue as a consequence of rapid dose falloff and the ability to tailor the field to the geometry of the tumor (18). The radiation-delivery system must be placed close to the tumor, limiting its use in the female pelvis to intracavitary applications (intrauterine, intracervical, and intravaginal) and interstitial applications (in which radiation sources are directly imbedded in the tumor). Intracavitary high-dose-rate brachyther-apy is delivered via a small-caliber intrauterine stent (tandem), which is often accompanied by ovoids placed in the vaginal fornices; interstitial radiation therapy is performed by loading small radioactive sources (such as iridium-192) into hollow needles or tubes that have been placed within the target tissue.
Proper placement of brachytherapy devices is essential for optimal treatment of the target tissue without exposure of normal structures (the intestine and bladder). At the University of Wisconsin, US guidance is frequently used to place intrauter-ine tandems (19) and may also be performed for calculation of treatment geometry (stage I endometrial carcinoma) (20) and placement of interstitial needles. Use of US guidance in this scenario can decrease therapy-related complications (bowel obstruction, fistula formation) and reduce treatment costs, since high-dose-rate brachytherapy is delivered over a short period and normally on an outpatient basis.
Intracavitary Brachytherapy
Indications.—The most common application of intracavitary radiation therapy is management of cervical carcinoma. It may also be used to deliver a booster dose to tumors of the bladder, urethra, or vagina. Most delivery systems combine a central uterine stent (tandem) and peripheral ovoids, which are placed in the lateral vaginal fornices under direct visualization. The combination results in a pear-shaped treatment field that conforms to the shape of the tumor. The tandem and ovoids are then afterloaded with the chosen radiation source. High-dose-rate afterloading can permit multifractionated brachytherapy on an outpatient basis, reducing the attendant risks of prolonged bed rest, including thrombophlebitis and pulmonary embolism.
Tandem diameters for high-dose-rate therapy are relatively small (3.2 mm), allowing placement by using only conscious sedation. Tandems may be placed without US guidance after uterine sounding, but when difficulty is encountered, portable US should be used to guide placement. Perforation is more likely when tumor grossly distorts cervical anatomy (Fig 10), in cases of cervical stenosis, in cases of prior pelvic irradiation, and when tumor involving the parametriumdistorts the uterus. Distortion by uterine fibroids and extreme retroflexion or anteflexion may also predispose to perforation. Because the dose per fraction ranges from 4 to 9 Gy, extreme care must be taken to avoid inadvertent overdosing of the intestine or bladder if perforation or myometrial penetration occurs.
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Figure 10a. Placement of a treatment tandem in a woman with stage IV cervical carcinoma. The patient had obliterated vaginal fornices and a distorted cervical os. (a) Longitudinal transabdominal US scan shows a tandem (arrow) perforating the uterine body, with the tip lying about 3 cm from the serosal surface. The tandem was withdrawn. By using a 30° tandem, satisfactory placement was achieved in this retroflexed uterus. (b) Longitudinal US scan shows the tip of the tandem (arrow) lying within the uterus approximately 3 mm from the serosal surface. Note the bright curved artifact extending posteriorly from the tandem tip (arrowheads). (c) Photograph shows a central uterine tandem with ovoids attached laterally. The ovoids are normally placed after the tandem is properly seated.
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Figure 10b. Placement of a treatment tandem in a woman with stage IV cervical carcinoma. The patient had obliterated vaginal fornices and a distorted cervical os. (a) Longitudinal transabdominal US scan shows a tandem (arrow) perforating the uterine body, with the tip lying about 3 cm from the serosal surface. The tandem was withdrawn. By using a 30° tandem, satisfactory placement was achieved in this retroflexed uterus. (b) Longitudinal US scan shows the tip of the tandem (arrow) lying within the uterus approximately 3 mm from the serosal surface. Note the bright curved artifact extending posteriorly from the tandem tip (arrowheads). (c) Photograph shows a central uterine tandem with ovoids attached laterally. The ovoids are normally placed after the tandem is properly seated.
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Figure 10c. Placement of a treatment tandem in a woman with stage IV cervical carcinoma. The patient had obliterated vaginal fornices and a distorted cervical os. (a) Longitudinal transabdominal US scan shows a tandem (arrow) perforating the uterine body, with the tip lying about 3 cm from the serosal surface. The tandem was withdrawn. By using a 30° tandem, satisfactory placement was achieved in this retroflexed uterus. (b) Longitudinal US scan shows the tip of the tandem (arrow) lying within the uterus approximately 3 mm from the serosal surface. Note the bright curved artifact extending posteriorly from the tandem tip (arrowheads). (c) Photograph shows a central uterine tandem with ovoids attached laterally. The ovoids are normally placed after the tandem is properly seated.
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Technique.—Guidance for placement of the central tandem is normally performed via the abdominal approach after the bladder has been distended with sterile water. Bladder filling may also create a more favorable angle between the cervix and uterus, aiding placement. Assessment of uterine anatomy aids in selection of tandem curvature, and real-time monitoring of the placement determines the need for directional deviations. Endorectal guidance may also be used for guidance but is more cumbersome, with the diagnostic radiologist and radiation therapist both present in a small working space.
At the University of Wisconsin, high-dose-rate brachytherapy is also used to treat stage I endometrial carcinoma that is inoperable due to obesity. In selected patients at high risk for local recurrence, it may also be used to reduce cuff recurrences, and it may be used to treat stage II endometrial carcinoma in combination with external-beam irradiation and surgery. Treatment is normally delivered with a single intrauterine tandem and ovoids in the vaginal fornices. US is routinely used in this scenario, both to ensure proper placement of the tandem within the endometrial cavity and to provide uterine measurements at several points. These measurements assist the radiation oncologist in shaping treatment geom-etry, which may be manipulated by changing the dwell times of the radiation source at several points along the length of the tandem (Fig 11).
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Figure 11a. Uterine measurement in a woman with inoperable stage IA carcinosarcoma of the uterus. US guidance was requested for endocavitary placement of the tandem and measurement of uterine dimensions. (a) Longitudinal US scan shows the tandem in the small uterus. Wall measurements were also obtained to assist in treatment planning. (b) Line drawing shows standard uterine measurements obtained for treatment planning. (c) Line drawing shows isodose curves superimposed on the uterine outline.
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Figure 11b. Uterine measurement in a woman with inoperable stage IA carcinosarcoma of the uterus. US guidance was requested for endocavitary placement of the tandem and measurement of uterine dimensions. (a) Longitudinal US scan shows the tandem in the small uterus. Wall measurements were also obtained to assist in treatment planning. (b) Line drawing shows standard uterine measurements obtained for treatment planning. (c) Line drawing shows isodose curves superimposed on the uterine outline.
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Figure 11c. Uterine measurement in a woman with inoperable stage IA carcinosarcoma of the uterus. US guidance was requested for endocavitary placement of the tandem and measurement of uterine dimensions. (a) Longitudinal US scan shows the tandem in the small uterus. Wall measurements were also obtained to assist in treatment planning. (b) Line drawing shows standard uterine measurements obtained for treatment planning. (c) Line drawing shows isodose curves superimposed on the uterine outline.
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Interstitial Brachytherapy
Indications.—Tumors that can be localized with radiography or US may be amenable to interstitial brachytherapy. Applications in the female pelvis include vulvar carcinoma, bladder carcinoma, and recurrent pelvic neoplasms including cervical and vaginal neoplasms. Interstitial implantation may be indicated when the anatomy is unfavorable for tandem and ovoid insertion, such as in a patient with a stenosed vagina or obliterated vaginal fornices or in cases of tumors that have not adequately regressed after standard radiation therapy. By using hollow needles temporarily implanted within an accessible volume of tissue, high doses of radiation can be delivered to areas that cannot be adequately treated with intracavitary brachytherapy techniques.
Technique.—Originally, interstitial implantation was performed with freehand placement of radium needles into the paracervical and paravaginal tissues. Transperineal templates are now used, allowing the operator to guide and secure needles within the tumor mass. Physical examination of the pelvis may be used to guide the location and depth of needle placement, but this method is inherently inaccurate. Inaccurate placement increases the risk of underdosing the target volume or causing unintended treatment of the nearby rectum and bladder with adverse reactions, including proctosigmoiditis, cystitis, vault necrosis, and fistula formation. Imaging guidance with CT and MR has been attempted to improve the accuracy of needle placement but is unwieldy.
Endorectal US transducers may be effectively used to guide placement of the needles in pelvic soft-tissue masses (21). With the patient in the dorsal lithotomy position and under spinal anesthesia, an endorectal probe with linear and axial imaging capability is placed. In addition, a combination of diatrizoate sodium meglumine and sterile saline solution is placed in the bladder with an indwelling Foley catheter. The pelvic tumor mass is then evaluated for relationship to the bladder and rectum as well as maximum transverse and longitudinal dimensions. In most practice situations, the patient will have undergone prior CT or MR imaging to provide planning information. Implantation normally begins with the longest transverse dimension of the target volume, with needles inserted into the most anterior aspect of the volume first followed by more posterior implantation to avoid imaging interference from the needles between the US transducer and the needle placement site. Needles are placed with the target volume monitored on transverse images first; the bladder, rectum, and extratumoral tissue are avoided. Once a needle is documented in the proper transverse plane, the probe can be switched to longitudinal imaging. The advancing needle tip is monitored until it is placed at the desired depth: to the margin of, but not beyond, the cranial aspect of the tumor (Fig 12).
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Figure 12a. Placement of interstitial treatment needles in a woman with a history of grade 2, stage IB squamous cell carcinoma of the cervix. The carcinoma was treated with radical hysterectomy and bilateral lymphadenectomy. (a) Axial MR image shows a 4 x 4 x 5-cm recurrent tumor (arrowheads) at the vaginal apex that involves the left posterolateral bladder wall. Note the proximity of the mass to the rectum (arrow). (b) Longitudinal endorectal US scan (7 MHz) of the pelvis shows the mass (arrowheads) between the intracystic Foley balloon and the rectum. (c) Longitudinal endorectal US scan shows a needle that was advanced too far cranially (arrow); the needle was withdrawn. (d) Longitudinal endorectal US scan shows the needle tip (arrowhead) at the margin of the mass. In this case, a total of 16 needles were implanted.
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Figure 12b. Placement of interstitial treatment needles in a woman with a history of grade 2, stage IB squamous cell carcinoma of the cervix. The carcinoma was treated with radical hysterectomy and bilateral lymphadenectomy. (a) Axial MR image shows a 4 x 4 x 5-cm recurrent tumor (arrowheads) at the vaginal apex that involves the left posterolateral bladder wall. Note the proximity of the mass to the rectum (arrow). (b) Longitudinal endorectal US scan (7 MHz) of the pelvis shows the mass (arrowheads) between the intracystic Foley balloon and the rectum. (c) Longitudinal endorectal US scan shows a needle that was advanced too far cranially (arrow); the needle was withdrawn. (d) Longitudinal endorectal US scan shows the needle tip (arrowhead) at the margin of the mass. In this case, a total of 16 needles were implanted.
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Figure 12c. Placement of interstitial treatment needles in a woman with a history of grade 2, stage IB squamous cell carcinoma of the cervix. The carcinoma was treated with radical hysterectomy and bilateral lymphadenectomy. (a) Axial MR image shows a 4 x 4 x 5-cm recurrent tumor (arrowheads) at the vaginal apex that involves the left posterolateral bladder wall. Note the proximity of the mass to the rectum (arrow). (b) Longitudinal endorectal US scan (7 MHz) of the pelvis shows the mass (arrowheads) between the intracystic Foley balloon and the rectum. (c) Longitudinal endorectal US scan shows a needle that was advanced too far cranially (arrow); the needle was withdrawn. (d) Longitudinal endorectal US scan shows the needle tip (arrowhead) at the margin of the mass. In this case, a total of 16 needles were implanted.
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Figure 12d. Placement of interstitial treatment needles in a woman with a history of grade 2, stage IB squamous cell carcinoma of the cervix. The carcinoma was treated with radical hysterectomy and bilateral lymphadenectomy. (a) Axial MR image shows a 4 x 4 x 5-cm recurrent tumor (arrowheads) at the vaginal apex that involves the left posterolateral bladder wall. Note the proximity of the mass to the rectum (arrow). (b) Longitudinal endorectal US scan (7 MHz) of the pelvis shows the mass (arrowheads) between the intracystic Foley balloon and the rectum. (c) Longitudinal endorectal US scan shows a needle that was advanced too far cranially (arrow); the needle was withdrawn. (d) Longitudinal endorectal US scan shows the needle tip (arrowhead) at the margin of the mass. In this case, a total of 16 needles were implanted.
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By using the perineal template as a guide, the entire target volume can be covered with properly spaced needles, optimally placed in the transverse and craniocaudal dimensions. If an intracavitary tandem is used in conjunction with the interstitial needles, the longitudinal rectal probe allows one to verify that the central tandem has entered the uterine cavity without perforation. Sources may then be afterloaded into the hollow needles after dosimetric evaluation.
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Conclusions
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US guidance enhances success in many gynecologic interventions. In our experience, it can reduce complications and decrease both the length of inpatient stays and the need for laparoscopic or open abdominal procedures.
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References
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S. G. Yarram, H. V. Nghiem, E. Higgins, G. Fox, B. Nan, and I. R. Francis
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[Abstract]
[Full Text]
[PDF]
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Abstract
Introduction
