1. Study Type: Single-center, single-arm, prospective study.

2. Sample Size: 20 patients with high-risk endometrial cancer were enrolled.

3. Treatment Procedure:

   The existing clinical oART (Online Adaptive Radiotherapy) workflow protocol for malignant tumors used in our department was applied.

   Procedures included simulation, target volume delineation, radiotherapy planning, and treatment delivery.

   External beam radiation therapy (EBRT) was delivered using moderate hypofractionation.

   If indicated, brachytherapy was performed after the completion of EBRT. When combined with chemotherapy, radiotherapy could be administered during chemotherapy intervals or after completion of chemotherapy.

4. Study Endpoints:

Primary Endpoint: Incidence of acute toxicity. Secondary Endpoints: 3-year failure-free survival (FFS) rate, incidence of chronic toxicity, quality of life (QoL), treatment costs, etc.

Research Process

1. Baseline Assessment Includes medical history inquiry, physical examination, and relevant laboratory/imaging tests. Complete the pre-radiotherapy Quality of Life Scale.
2. Treatment Plan

External Beam Radiotherapy (EBRT): Utilize online adaptive radiotherapy technology to irradiate the vagina and pelvic lymph node drainage areas. Employ moderate fractionation. Prescription Dose: 40.05 Gy / 15 fractions, administered once daily, five times per week.

Brachytherapy: Commence after completion of EBRT. Utilize 3D intracavitary brachytherapy technology. Fraction Dose: 4-6 Gy, for a total of 2-3 fractions, administered with an interval of 1-2 days between fractions.

3. Follow-up Visits

1. During Radiotherapy: Monitor CBC weekly and Biochemistry Panel every 2 weeks. Perform radiotherapy-related toxicity assessment.
2. Post-Radiotherapy:

Timepoints: End of radiotherapy; 3 months post-radiotherapy; 6 months post-radiotherapy; then every 6 months thereafter, until 3 years post-radiotherapy.

Follow-up Content: Includes medical history inquiry, physical examination, and Quality of Life assessment; Laboratory/Imaging Tests.

Inclusion Criteria:

• Age : 18-70 years old.
• Performance Status :

ECOG score 0-2.

• Expected to comply with oART (Online Adaptive Radiotherapy) workflow.
• Initial Surgical Treatment :

Total hysterectomy and bilateral salpingo-oophorectomy ± Pelvic and/or para-aortic lymph node dissection/sampling or sentinel lymph node biopsy.

• Pathological Staging & Histology (per FIGO 2009):

Stage I :

Grade 3 endometrioid adenocarcinoma with superficial myometrial invasion and extensive LVSI (Lymphovascular Space Invasion).

Grade 2 endometrioid adenocarcinoma with deep myometrial invasion and extensive LVSI.

Grade 3 endometrioid adenocarcinoma with deep myometrial invasion. Stage II-IIIC1 : Endometrioid carcinoma. Stage I-IIIC1 : Serous carcinoma or clear cell carcinoma.

• Informed Consent :
• Patients and families fully understand the study protocol.
• Voluntarily participate and sign informed consent forms before enrollment

Exclusion Criteria:

• Prior Radiotherapy : History of abdominal or pelvic irradiation.
• Treatment Interval :

Without adjuvant chemotherapy: >12 weeks between surgery and radiotherapy initiation.

With adjuvant chemotherapy: >6 months between surgery and radiotherapy initiation.

• Malignancy History : Prior diagnosis of other malignancies.
• Pregnancy/Lactation : Pregnant or breastfeeding women.
• Active Infection : Fever or uncontrolled active infection.
• Inflammatory Bowel Disease (IBD) : History of IBD (regardless of activity status).
• Comorbidities : Severe conditions affecting trial compliance, including: Unstable cardiac disease requiring treatment, renal impairment, chronic hepatitis, poorly controlled diabetes, psychiatric disorders