Treating the prostate together with the pelvic lymph nodes adds a large nodal volume that runs up the pelvic side walls, usually delivered as a simultaneous integrated boost with the prostate at the highest dose. The planning problem grows accordingly: rectum and bladder still matter around the prostate, but small and large bowel now sit alongside the nodal targets.
Adding the pelvic lymph nodes turns a small, compact prostate plan into a large one that reaches up to the common iliac vessels. Randomized evidence such as POP-RT supports elective nodal treatment in higher-risk disease.
Most plans use a simultaneous integrated boost (SIB): several dose levels in one plan, delivered in the same number of fractions. Published protocols, for example, give three SIB schedules — 20, 25 or 39–40 fractions — with separate dose levels for the prostate and involved seminal vesicles, uninvolved seminal vesicles, involved nodes and elective nodes.
What changes for the planner:
As for prostate-only treatment, with a longer scan and more attention to the bowel.
A planning CT that extends high enough to cover the full nodal volume with margin.
The scan typically runs from L3/L4 to below the ischial tuberosities; the upper level may be extended when nodes are treated.
Intravenous contrast at simulation to show the pelvic vessels.
Elective nodal volumes are drawn around the iliac vessels, so seeing the vessels clearly makes nodal contouring more reproducible. IV contrast is often considered for this.
Image fusion aligns an outside scan with the planning CT so the target can be drawn using information the CT doesn't show. When the pelvic nodes are treated, staging with PSMA PET/CT is recommended — it shows involved nodes and disease within the prostate. MRI is fused for the prostate and seminal vesicles, as in prostate-only treatment.
Involved nodes receive a higher dose than elective ones, so knowing exactly which are involved changes the target volumes. In a randomized trial, PSMA PET/CT found pelvic nodal or distant spread more accurately than CT and bone scan. Involved nodes are small and sit along the vessels, so check the registration at each node rather than only at the prostate.
A comfortably full, reproducible bladder.
With nodes in the field, bladder filling also affects how much small bowel sits in the pelvis — a fuller bladder can displace bowel upward and away from the nodal PTV.
The same measures used for prostate-only treatment. More →
The prostate boost still sits against the rectum; see the definitive page for details.
What each volume represents. Nodal regions, margins and dose levels come from your protocol.
The prostate and any involved seminal vesicles, receiving the highest dose level.
Planned exactly as in prostate-only treatment; rectal and bladder dose around it still matter most.
Seminal vesicles not involved by tumor, treated to a lower dose.
Giving uninvolved seminal vesicles a lower dose level reduces dose to the rectum and bladder behind and below them.
Nodes that are visibly involved, typically on PSMA PET, with a small expansion.
They receive a higher dose than elective nodes, which can put a high-dose region right next to bowel.
Pelvic node regions at risk — obturator, internal, external and common iliac and presacral, depending on the protocol.
The nodal volume is the largest target and the one closest to bowel. Consensus atlases define which regions to include and where each one starts and stops.
An expansion of each CTV for setup and motion uncertainty.
The prostate moves independently of the pelvic bones and nodes. Image guidance usually matches on the prostate, so the nodal PTVs have to allow for that difference.
Click an organ for its anatomy, why it matters and contouring resources. Superscripts link to the study behind each value.
| Organ | 60 Gy / 20 fxNodes 44 Gy | 68 Gy / 25 fxNodes 45–50 Gy | 78–80 Gy / 39–40 fxNodes 54–60 Gy |
|---|---|---|---|
| Rectum | |||
| Bladder | |||
| Small Bowel25 fx values are acceptable limits; stricter ideal targets exist. | — |
| |
| Large Bowel / Sigmoid39–40 fx values are general conventional limits, not prostate-specific. | — | ||
| Femoral Heads |
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| |
| Penile BulbNever at the expense of PTV coverage. | — | — |
Values quoted from eviQ 3657 (last reviewed 7 November 2024; review due 31 December 2026) and CORSAIR, checked by DoseLab on 2026-09-23. Verify against your protocol, institutional policy and physician directive before clinical use.
Efficacy results of the POP-RT randomized phase 3 trial. Citation as given in the eviQ reference list; not yet checked against the journal.
Late toxicity and quality-of-life results from the randomized POP-RT trial of prostate-only versus whole-pelvic radiotherapy. Citation as given in the eviQ reference list.
NRG Oncology's page for RTOG 0924, a phase 3 trial of androgen deprivation and high-dose radiotherapy with or without whole-pelvic radiotherapy.
NRG Oncology's updated international consensus atlas for elective pelvic lymph node volumes in prostate cancer.
Consensus guideline and atlas for pelvic node contouring. Citation as given in the eviQ reference list; not yet checked against the journal.
Australian and New Zealand consensus recommendations for node-positive prostate cancer. Citation as given in the eviQ reference list; not yet checked against the journal.
Randomized phase 3 non-inferiority trial of conventional versus moderately hypofractionated IMRT for localized prostate cancer. A correction to this article was also published.
A 2010 journal supplement summarizing dose-volume and outcome data for normal tissues, organized by organ.
RTOG consensus panel atlas of male and female pelvic normal tissues. Citation as given in the eviQ reference list; not yet checked against the journal.