Table 1 Contouring protocol for target volumes
From: A prospective study of nomogram-based adaptation of prostate radiotherapy 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 | 5Â mm margin around CTVLN | If CTVLN contoured |