Figure 6a. Squamous cell carcinoma in a 62-year-old man. (a) Pretreatment chest radiograph shows a cavitary mass in the right lower lobe. The patient was treated with a radiation dose of 50 Gy with portals that included lung tissue adjacent to the mass as well as the lower mediastinum (cf Fig 5c). (b) Radiograph obtained 4 months after completion of radiation therapy shows faint, ill-defined areas of increased opacity around the cavitary mass (arrows).