FIGURE 1.
CTV contours and organs at risk are contoured by radiation oncologists on dedicated planning CT (CT simulation). (A) CTV for intact (definitive) prostate is prostate gland itself with or without pelvic nodes and seminal vesicles. (B) CTV for SRT includes prostate bed with or without pelvic nodes. CTV is usually drawn in absence of radiographic evidence of recurrent disease. Instead, CTVs are based on consensus guidelines to encompass prostate bed with or without pelvic lymph nodes. The most commonly used external-beam dose-fractionation schedules for definitive prostate radiotherapy deliver 75.6–79.2 Gy in fractions of 1.8–2 Gy, whereas those for SRT deliver 66–72 Gy. When included, pelvic nodal volumes are prescribed 45–50.4 Gy.