RadioGraphics, Vol 15, 1483-1488, Copyright © 1995 by Radiological Society of North America
Use of multiplanar reformatted radiographic and digitally reconstructed radiographic images for planning conformal radiation therapy
IJ Das, KP McGee, DA Fein, SJ Milito, G Shammo, WJ Curran Jr and LR Coia
Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
A three-dimensional treatment planning system capable of gantry,
collimator, and table rotations is required for a noncoplanar conformal
therapy. Unfortunately, such a system is not widely available. A method in
which multiplanar reformatted radiographic (MPR) and digitally
reconstructed radiographic (DRR) images are used is presented for conformal
treatment of brain tumors. A head phantom containing a target volume was
scanned on a computed tomographic (CT) simulator. The coronal MPR images
were digitized on a treatment planning system to create a conformal block
of the planned treatment field. The DRR images were generated on the CT
simulator with the setup parameters calculated from the treatment planning
system. A second set of conformal blocks was generated based on DRR images
of the fields. The accuracy of the MPR- and DRR-generated blocks was
verified on the vertex field. The differences between the actual planning
target volume and the field edges of the MPR and DRR blocks were within +/-
4 mm and +/- 2 mm, respectively. The authors conclude that the MPR and DRR
images could be successfully used to generate conformal blocks and for
treatment planning of noncoplanar beams in radiation therapy.
