Figure 7b. Three patterns of radiation-induced lung injury after 3D conformal radiation therapy. (a-c) Modified conventional pattern in a 53-year-old woman with adenocarcinoma. (a) CT scan obtained before treatment shows a mass in the left lower lobe. (b) CT scan obtained 1 month after completion of radiation therapy shows a decrease in the size of the mass along with ground-glass attenuation, which is indicative of pneumonitis. (c) CT scan obtained 5 months after completion of radiation therapy shows organization of the pneumonitis into fibrosis. Note the volume loss, consolidation, and air bronchograms, as in conventional fibrosis; however, the fibrosis is localized to a small area of the lung. (d) Masslike pattern in a 67-year-old man with squamous cell carcinoma. CT scan obtained 14 months after completion of radiation therapy shows the consolidation and bronchiectasis of fibrosis. The fibrosis forms a masslike area of increased attenuation, which could be mistaken for a malignancy. (e) Scarlike pattern in a 60-year-old woman with poorly differentiated non-small cell carcinoma. CT scan obtained 5 years after completion of radiation therapy shows only a linear band of fibrosis, which resembles a scar.