Table 1.

Contouring protocol for target volumes

Structure	Contouring protocol	Condition
CTVP	Prostate as defined using CT and MRI imaging + any extra-prostatic extension as noted on examination or pre-ADT imaging	All patients
CTVECE	3 mm isotropic margin from CTVP, excluding overlap with rectum	If ECE risk ≥ 15 %
CTVSVI	Entire bilateral seminal vesicles (only contoured if known seminal vesicle involvement)	If SV involved
CTVSVA	Proximal 20 mm of SV, measured obliquely along long axis of SV (only contoured for adjuvant treatment of seminal vesicles)	If SVI risk ≥ 15 %
CTVLN	Pelvic nodes: 7 mm margin around obturator, pre-sacral, and external and internal iliac vessels contoured as per RTOG consensus guidelines [21], up to 10 mm inferior to the sacral promontory)	If LNI risk ≥ 15 %
PTV70	If no SV involvement: 5 mm margin around CTVP If SV involvement: 5 mm margin around CTVP + 7 mm margin around CTVSVI anteriorly and posteriorly and 5 mm otherwise	All patients
PTV61.6	If SV involvement or SVI risk <15 %: 5 mm margin around CTVECE If no SV involvement and SVI risk ≥15 %: 5 mm margin around CTVECE + 7 mm margin around CTVSVA anteriorly and posteriorly and 5 mm otherwise	If CTVECE or CTVSVA contoured
PTV50.4	5 mm margin around CTVLN	If CTVLN contoured