Pelvic Ultra-Hypofractionated Adjuvant Radiotherapy for Endometrial Cancer (PURE-cohort)

Pelvic Ultra-Hypofractionated Adjuvant Radiotherapy for High-Intermediate and High-Risk Endometrial Cancer: A Prospective Multicenter Phase II Safety Cohort Study

The PURE trial is a prospective multicenter phase II study evaluating the safety and feasibility of ultra-hypofractionated adjuvant pelvic radiotherapy in patients with high-intermediate-risk and high-risk endometrial cancer following surgery. The study investigates a treatment regimen consisting of 27.5 Gy delivered in five fractions using modern image-guided IMRT/VMAT techniques. The primary objective is to assess acute gastrointestinal and genitourinary toxicity according to CTCAE version 5.0.

PURE is a prospective multicenter phase II safety study designed to evaluate ultra-hypofractionated adjuvant pelvic radiotherapy in patients with high-intermediate-risk and high-risk endometrial cancer. Eligible patients will receive 27.5 Gy in five fractions delivered over approximately two weeks using image-guided IMRT/VMAT. The study aims to determine whether this regimen achieves acceptable toxicity while preserving treatment efficacy and quality of life. Secondary endpoints include late toxicity, treatment compliance, patient-reported outcomes, locoregional control, disease-free survival, and overall survival. The study employs a Simon optimal two-stage design and plans to enroll 46 evaluable patients.

Inclusion Criteria:

1. Aged > 18 years.
2. Histologically confirmed diagnosis of endometrial cancer post hysterectomy: endometrial adenocarcinoma, serous or clear cell carcinoma, or carcinosarcoma or dedifferentiated carcinoma.
3. Patients candidates for adjuvant pelvic (Cht)EBRT treatment (+/- vaginal cuff brachytherapy), categorized by Intermediate-high risk and high risk primary endometrial cancer based on recent ESGO/ESTRO/ESMO Guidelines (2025).
4. Patient is willing and able to give informed consent to participate in this clinical trial.
5. Patient must be willing and able to complete the QLQ-C30 questionnaire with EN-24 companion as described in the study protocol
6. Possibility of fiducial marker placement on vaginal vault.
7. Dosimetric feasibility based on OAR constraint and targets objective

Exclusion Criteria:

1. Prior pelvic or abdominal radiation therapy delivered.
2. Inflamatory bowel disease of other contraindication to pelvic radiotherapy.
3. Previous abdominal or pelvic complicated surgery.