Appendix 2.

Definition of target volumes and planning target volume margins for EBRT in published clinical protocols

Protocol/reference(s)	GTV and CTV	PTV
MD Anderson: RCT of 70 Gy vs 78 Gy Kuban, 200814	•CTV = prostate and SVs	•Conventional 4-field box, 11 × 11 cm for AP/PA fields, 11 × 9 cm for lateral fields, then reduce all fields to 9 × 9 cm •On 70-Gy arm, CT performed to confirm that margins from CTV to block edge were 1.25 to 1.5 in anterior and in dimensions and 0.75 × 1.0 cm in posterior and superior dimensions
PROG 9509 RCT of 70.2 Gy vs 79.2 Gy Zietman, 201024	•CTV = prostate + 5-mm margin	•CTV + 7-10 mm
GETUG: RCT of 70 vs 80 Gy Beckendorf, 200425	•CTV = prostate ± SVs	•Phase 1: prostate and SVs + 10-mm margin, reduced posteriorly to 5 mm •Phase 2: prostate alone with same margins
Dutch CKVO96-10: RCT of 68 Gy vs 78 Gy Al-Mamgami, 200826	• CTV = GTV ○ Group 1: prostate only ○ Group 2-3: prostate and SVs (for first 50-68 Gy), then prostate only for remainder ○ Group 4: prostate and SVs	•CTV + 10 mm during first 68 Gy •CTV + 5 mm (except 0 mm toward the rectum) for last 10 Gy in high-dose arm
UK MRC RT01: RCT of 64 Gy vs 74 Gy Dearnaley, 200727, 28	•64-Gy arm: GTV = prostate ± base of SVs (for phase 1 GTV) • 74-Gy arm: GTV = ○ Prostate + SVs (for phase 1 GTV) ○ Prostate ± base of SVs (for phase 2 GTV) •CTV = GTV + 5 mm	•CTV + 5- to 10-mm margin
RTOG 0126:29 RCT of 70.2 Gy vs 79.2 Gy	•GTV = prostate •CTV = prostate and proximal SVs (up to 10 mm); may be reduced to prostate only after 55.8 Gy	•CTV + a minimum of 5 mm in all directions. Superior and inferior margins should be 5-10 mm depending on spacing of planning CT
RTOG 0924:30 RCT of high-dose RT ± pelvic RT in intermediate- and high-risk patients	•GTV1 = all known disease on planning CT, urethrogram, clinical information •GTV2 = prostate + proximal SVs •CTV1 = prostate and SVs + LNs (obturator, external iliac, proximal internal iliac, common iliac) + 7-mm margins (excluding bone) •CTV2 = GTV2	•PTV1 = CTV1 + 5-15 mm •PTV2 = CTV2 + 5-10 mm •Individual selection of PTV margin should be based on spacing of planning CT

CTV, clinical target volume; EBRT, external-beam radiation therapy; GETUG, Groupe d'Etude des Tumeurs Uro-Génitales; GTV, gross tumor volume; PTV, planning target volume; RCT, randomized controlled trial; SVs, seminal vesicles. Other abbreviations as in Appendix 1.

All studies listed use conventionally fractionated radiation therapy (ie, 1.8-2.0 Gy/fraction).