A Study of Short-course Hypofractionated Online-adaptive Radiotherapy for the Post-operative Treatment of Endometrial Cancer: Tolerability and Feasibility

NCT07675733 | Not Yet Recruiting DMC

• 1 other identifier: CCR6365
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to assess the safety and feasibility of using a new form of radiotherapy technology, known as CT online-adaptive radiotherapy, to reduce the number of treatment sessions required in post-operative radiotherapy for patients with endometrial cancer, from 25 sessions over 5 weeks to 5 sessions over a week and a half. The main questions it seeks to answer are:

• If it is safe to deliver the radiotherapy in a smaller number of treatment sessions with a larger dose per session by utilising the CT online-adaptive technology
• If it is feasible for this treatment to be delivered using the CT online-adaptive technology in a clinical trial All participants who enrol in the study would be offered the trial treatment of the radiotherapy being delivered in 5 sessions. Any potential participants who are subsequently found to be ineligible during the radiotherapy planning process would be excluded from the trial treatment of a higher dose over 5 sessions, but would still be offered the CT online-adaptive technology over 25 sessions outside of the trial. Participants would undergo the trial treatment with the radiotherapy being delivered in 5 sessions over a week and a half using the CT online-adaptive technology, with any issues during the treatment delivery recorded, and a questionnaire to complete at the end of treatment to see how the new technology was tolerated by participants. Participants will have their side effects recorded by the trial team before, during and after their treatment for 2 years following the radiotherapy. During this time period participants will also be asked to complete patient questionnaires to assess their perception of side effects and their quality-of-life after undergoing the treatment. Participants will also have blood tests before, during and after the radiotherapy for 3 months to check for any potential problems with blood counts as a result of the trial treatment. During the 2 years of follow-up after the radiotherapy, participants will also have assessments for if the cancer has returned, which will be completed by a combination of clinical examination, and CT scans. Following completion of the 2 years of trial follow-up, participants would remain on general follow-up to assess for if the cancer has returned, or for any longer term side effects for up to 5 years after the treatment, but this follow-up will be outside of the trial without the request for ongoing completion of participant questionnaires.

Conditions

Endometrial Carcinoma (EC)

Keywords

Online Adaptive Radiotherapy; Hypofractionation; Ultrahypofractionation; Endometrial; CT Online Adaptive Radiotherapy

Outcome Measures

Primary Outcomes (1)

• Percentage of patients experiencing acute grade 3 or 4 gastrointestinal or genitourinary toxicity, attributable to radiotherapy

  • Percentage of patients experiencing acute grade 3 or 4 gastrointestinal or genitourinary toxicity, attributable to radiotherapy, up to 12 weeks following radiotherapy (as assessed by National Cancer Institute Clinician graded Common Terminology Criteria for Adverse Events (CTCAE) 6.0)

  From beginning radiotherapy, up to 12 weeks following completion of radiotherapy

Secondary Outcomes (12)

• Feasibility of a CT Online Adaptive workflow

  From Day 1 of radiotherapy treatment course, assessed at every treatment fraction for all 5 treatment fractions, up to and inclusive of final 5th radiotherapy fraction (an average duration of 10 days)

• Patient-reported acute GI and GU toxicity incidence, severity, and longitudinal change from baseline up to 12 weeks following radiotherapy

  From beginning radiotherapy, up to 12 weeks following completion of radiotherapy

• Percentage of patients experiencing all acute grade 2 + toxicity, including haematological toxicity, attributable to radiotherapy, up to 12 weeks following radiotherapy

  From beginning radiotherapy, up to 12 weeks following completion of radiotherapy

• Percentage of patients experiencing all acute grade 3 / 4 toxicity, including haematological toxicity, attributable to radiotherapy, up to 12 weeks following radiotherapy

  From beginning radiotherapy, up to 12 weeks following completion of radiotherapy

• Percentage of patients experiencing all late grade 2 + toxicity, attributable to radiotherapy, up to 2 years following radiotherapy

  From beginning radiotherapy, up to 2 years following completion of radiotherapy

Study Arms (1)

Single-arm - Hypofractionated online-adaptive radiotherapy 30Gy/5# via CT-OART

EXPERIMENTAL

Single-arm - All 30 patients to undergo experimental arm of hypofractionated online-adaptive radiotherapy for the post-operative treatment of endometrial cancer with a dose of 30 Gray in 5 fractions, delivered on alternate weekdays over a week and a half duration, via a CT-online adaptive approach (CT-OART)

Radiation: Hypofractionated CT online adaptive radiotherapy (CT-OART) with dose of 30 Gray in 5 fractions, over one and a half weeks

Interventions

Hypofractionated CT online adaptive radiotherapy (CT-OART) with dose of 30 Gray in 5 fractions, over one and a half weeks RADIATION

Hypofractionated CT online adaptive radiotherapy (CT-OART) with dose of 30 Gray in 5 fractions, over one and a half weeks, for the post-operative treatment of endometrial cancer

Single-arm - Hypofractionated online-adaptive radiotherapy 30Gy/5# via CT-OART

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Histologically confirmed endometrial carcinoma - inclusive of endometrioid adenocarcinoma, carcinosarcoma, clear cell carcinoma, serous carcinoma, dedifferentiated carcinoma, mucinous carcinoma, mixed carcinoma
• Age greater than 18 years old
• Disease fully resected at time of surgery
• Indication for post-operative external beam radiotherapy: high-intermediate risk and high-risk disease (ESGO-ESTRO-ESP guideline), or at the discretion of treating Clinical Oncologist
• If adjuvant systemic chemotherapy is indicated, participants will still be eligible for trial participation, provided there is a minimum 3-week gap between completing chemotherapy and beginning external beam radiotherapy
• If adjuvant vaginal vault brachytherapy boost is indicated, participants will still be eligible for trial participation, with a minimum gap of 1 day from completion of external beam radiotherapy to first fraction of brachytherapy
• WHO Performance Status 0 - 2
• Informed written consent

You may not qualify if:

• Previous pelvic radiotherapy
• Contraindication to receiving external beam radiotherapy
• Residual disease identified on post-operative imaging
• FIGO 2023 Stage 3C2 disease requiring extended para-aortic treatment field
• Hip prostheses or other metal work within the imaging field which would produce significant imaging artifact
• Indication for adjuvant concurrent chemo-radiotherapy

Sponsors & Collaborators

• Royal Marsden NHS Foundation Trust: lead

Study Sites (1)

The Royal Marsden Hospital - Sutton

Sutton, SM2 5PT, United Kingdom

Location

MeSH Terms

Conditions

Endometrial Neoplasms

Condition Hierarchy (Ancestors)

Uterine Neoplasms; Genital Neoplasms, Female; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Uterine Diseases; Genital Diseases, Female; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Genital Diseases

Study Officials

• Susan Lalondrelle, Consultant Clinical Oncologist

  Royal Marsden NHS Foundation Trust

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Benjamin James Thomas, Clinical Research Fellow

CONTACT

+442086426011; SHORTEN.trial@rmh.nhs.uk

Kylie Fitch, Trial Manager

CONTACT

+442086426011; SHORTEN.trial@rmh.nhs.uk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 12, 2026
• First Posted: June 30, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): May 1, 2028
• Study Completion (Estimated): May 1, 2030
• Last Updated: June 30, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL

Locations

GB (1)