Endometrium & Cervix — Post-operative

GYNEndometriumEndometrial cancerCervixPost-operativeIMRTVMATITVVaginal cuffImage fusionConventional fractionation
Overview

Post-operative pelvic radiotherapy after hysterectomy for endometrial or cervical cancer. The target is the vaginal cuff and the pelvic nodes; the planning work is in covering a cuff that moves with bladder filling while keeping dose off the bowel that falls into the pelvis after surgery.

Start here: I’m planning my first GYN case — a step-by-step learning roadmap.

Schedules

After hysterectomy, pelvic radiotherapy treats the vaginal cuff, the paravaginal tissues and the pelvic nodes to 45 Gy in 25 fractions or 50.4 Gy in 28. It is used for endometrial cancer at higher risk of pelvic recurrence and for cervical cancer with risk factors at surgery, sometimes with concurrent chemotherapy — the same planning approach serves both.

Two related options change what is planned:

  • Vaginal cuff brachytherapy alone replaces pelvic external beam for some endometrial cancers, treating only the top of the vagina — see GYN Brachytherapy.
  • A cuff boost — brachytherapy or an external beam boost after the pelvic course — is considered in selected cases, such as close or positive vaginal margins.

One template asks for treatment to start 4–9 weeks after surgery. Your protocol sets the dose, the boost and whether chemotherapy is given.

Simulation & Setup

After hysterectomy the vaginal cuff moves with bladder and rectal filling, and bowel often drops into the empty pelvis. Simulation is built around those two problems.

Position and immobilization
Supine or prone, with the legs in a custom or indexed device so the pelvis sits the same way every day.

What is it?

Supine or prone in an immobilization device — for example a custom vacuum cushion or an indexed leg support.

Why does it matter?

The nodal volumes follow the pelvic vessels close to bone, so a reproducible pelvis keeps them in place day to day.

Vaginal markers
Seeds or clips at the vaginal apex show where the cuff is on CT.

What is it?

Radiopaque marker seeds or clips placed at the vaginal apex before simulation. One template advises against markers that distend the vagina.

Why does it matter?

The vaginal cuff is hard to see on CT. A marker at the apex shows where the top of the vagina is, which anchors the vaginal CTV.

Bladder filling and the vaginal ITV
A full- and an empty-bladder scan show how far the cuff moves, and the vaginal ITV covers both positions.

What is it?

A moderately full bladder for simulation and treatment, plus a second scan with the bladder empty. The vaginal CTV is contoured on the full-bladder scan and expanded to cover the cuff's position on the empty-bladder scan, giving the vaginal ITV. Planning is done on the full-bladder scan.

Why does it matter?

Bladder and rectal filling move the vaginal cuff from day to day. With an ITV, the cuff stays inside the target whatever the day's bladder filling. A full bladder also lifts small bowel out of the pelvis.

Planning CT
A thin-slice CT from about L1 to mid-thigh, with IV contrast for the vessels the nodal volumes follow.

What is it?

A CT with slices of 3 mm or less, from about L1 to mid-thigh, with IV and bowel contrast allowed.

Why does it matter?

The nodal CTV is drawn around the iliac vessels, so contrast makes them clear. If the planning scan has contrast, its density is overridden for dose calculation.

Image fusion — MRI and PET/CT
Diagnostic pelvic MRI and/or PET/CT can be fused to help define any residual disease.

What is it?

Image fusion aligns an outside scan with the planning CT so the target can be drawn using information the CT doesn't show. One template recommends fusing a diagnostic pelvic MRI and/or PET/CT, ideally taken close in time to the planning scan.

Why does it matter?

After surgery there is usually no gross tumor, but residual nodal disease becomes a nodal GTV, and fused imaging helps find it. The same template discourages deformable registration of the diagnostic MRI and asks that PET/CT registrations be reviewed with caution.

Daily imaging
Daily IGRT with IMRT, usually matched to bone, with the vaginal ITV covering the cuff's movement.

What is it?

Daily image guidance with IMRT — usually cone-beam CT matched to the bony anatomy.

Why does it matter?

With an ITV built from the bladder-filling scans, the cuff should stay inside the target on a bony match. CBCT also shows when the bladder or rectum is very different from the plan.

Target Delineation

What each volume represents. Expansions, nodal regions and dose levels come only from your protocol.

GTV — Only if disease remains

Definition

Usually none after surgery. Residual nodal disease is contoured as a nodal GTV.

Why it matters

Post-operative treatment targets microscopic disease, so the CTV, not a GTV, defines the plan in most cases.

Contouring resources

Organ contouring guides →

Relevant protocols

Vaginal CTV / ITV — Vaginal cuff and paravaginal tissues

Definition

The upper vagina and the paravaginal tissues out toward the pelvic sidewall, contoured on the full-bladder scan and expanded to the cuff's position on the empty-bladder scan.

Why it matters

Recurrence after hysterectomy is most likely at the vaginal cuff. The final vaginal ITV often includes the back wall of the bladder and may include the front wall of the rectum, which affects those organs' doses.

Contouring resources

Organ contouring guides →

Relevant protocols

Nodal CTV — Pelvic nodes

Definition

The external and internal iliac and obturator nodal regions, often with the common iliac nodes, drawn around the vessels — with the presacral region added when the protocol calls for it.

Why it matters

The pelvic nodes are the next most common site of spread. The NRG/RTOG consensus atlas shows the boundaries of each region and where to stop at the top and bottom.

Contouring resources

Organ contouring guides →

Relevant protocols

PTV — Planning target volume

Definition

The vaginal ITV and nodal CTV expanded for setup uncertainty.

Why it matters

Bowel lies just above and around the nodal PTV, so the bowel space limit and PTV coverage are usually the main trade-off.

Contouring resources

Organ contouring guides →

Organs at Risk & Dose Constraints

Click an organ for its anatomy, why it matters and contouring resources. Superscripts link to the source behind each value.

Organ45–50.4 Gy / 25–28 fxPost-operative pelvis
Small BowelBoth use a contour of the space the bowel can occupy, but defined differently — match your contour to the source.
  • Bowel space V40 Gy ≤30%1
  • Bowel cavity V45 Gy <195 cc2
Rectum
  • V40 Gy ≤80%1
Bladder
  • V45 Gy ≤35%1
Femoral Heads
  • D15% ≤30 Gy, D0.03 cc ≤50 Gy1
Pelvic Bone MarrowPelvic bones as a surrogate, including the femoral heads but not the necks.
  • V10 Gy ≤90%, V40 Gy ≤37%1
  • Mean ≤27 Gy1
  • NRG values are the template's per-protocol (ideal) levels; its variation-acceptable levels are much looser (e.g. rectum V40 Gy <100%, bladder and bowel space <70%).
  • The vaginal ITV often includes the back wall of the bladder and the front wall of the rectum, so some rectal and bladder dose is unavoidable.
  • The template asks for no volumetric organ limits for vaginal cuff brachytherapy — see the GYN brachytherapy page.
References (2)
  1. NRG endometrial RT template — NRG Oncology Protocol Development Template for Radiation Therapy — Gynecological Cancer: Endometrial Cancer (post-operative treatment after hysterectomy). NRG Oncology protocol template Source
  2. QUANTEC summary — Use of normal tissue complication probability models in the clinic. Int J Radiat Oncol Biol Phys. 2010;76(3 Suppl):S10–S19 Source

Values quoted from NRG endometrial RT template and QUANTEC summary, checked by DoseLab on 2026-09-30. Verify against your protocol, institutional policy and physician directive before clinical use.

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Protocols & Literature

Clinical resourceSource Verified
NRG Oncology Protocol Development Template for Radiation Therapy — Gynecological Cancer: Endometrial Cancer (post-operative treatment after hysterectomy)
Lee YC, Kim H, Tsai P, Liang X, Padgett K, Portelance L · NRG Oncology Medical Physics Subcommittee / Radiation Oncology Committee · 2024

The NRG Oncology template for the radiation section of a post-operative endometrial cancer trial. It covers supine or prone setup, vaginal apex markers, full- and empty-bladder scans fused to build the vaginal internal target volume, nodal CTV guidance, standard structure names, example prescriptions (45 or 50.4 Gy), example vaginal cuff brachytherapy schedules alone or as a boost, and per-protocol and variation-acceptable organ goals. For cuff brachytherapy it asks for dose points along the cylinder and verification of the dome position rather than volumetric organ limits. Its values are examples meant to be edited for each trial.

View Source Details
Contouring atlasUnder Review

NRG Oncology/RTOG consensus update on the clinical target volumes for post-operative pelvic IMRT after hysterectomy for endometrial or cervical cancer — vaginal cuff, parametria and the pelvic nodal regions. NRG hosts the atlas images and viewer packages on its gynecologic CIRO page. Citation checked against Europe PMC.

View Source Details
Landmark trialUnder Review

PORTEC-2 randomized women with high-intermediate risk endometrial cancer to vaginal brachytherapy or pelvic external beam radiotherapy after surgery. Vaginal brachytherapy gave similar vaginal control with fewer bowel side effects. Citation checked against Europe PMC.

View Source Details
Contouring atlasUnder Review
Female RTOG Normal Pelvis Atlas
Gay HA, Barthold HJ, O'Meara E, et al. · NRG Oncology / RTOG · 2012

NRG Oncology's hosted copy of the RTOG female normal pelvis atlas (from the RTOG pelvic normal tissue consensus): bladder, rectum, sigmoid, bowel, femoral heads and other pelvic organs, as a PowerPoint and an interactive viewer.

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AAPM reportUnder Review

AAPM Task Group 132 report on image registration and fusion in radiotherapy. It reviews rigid and deformable registration, points out that every registration carries an uncertainty that should be understood and communicated, and gives recommendations for commissioning and quality assurance of registration software and for checking individual registrations. Citation checked against Europe PMC.

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Clinical resourceSource Verified

Endorsed eviQ protocol for adjuvant pelvic external beam radiotherapy after hysterectomy for endometrial cancer. It covers simulation with a vaginal marker and optional full- and empty-bladder scans, 45–50.4 Gy in 25–28 fractions, an optional vault boost by EBRT or HDR brachytherapy, the vaginal–parametrial and nodal CTVs referenced to the NRG/RTOG post-operative consensus, and an organ table. Its review is due 31 December 2026.

View Source Details

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