Figure 9. Biopsy-proved Gleason grade 8 adenocarcinoma in a 74-year-old man with a PSA level of 20.2 ng/mL. T2-weighted axial MR image shows a midline low-signal-intensity lesion in the peripheral zone with focal smooth bulging of the capsule. The patient was treated with intensity-modulated radiation therapy. The MR imaging findings, in particular the close spatial relationship between the tumor (T) and rectal wall, were helpful for designing the radiation treatment plan.