Hypofractionated External Beam Radiotherapy With Adaptive Planning for Endometrial and Cervical Cancers

The investigators hypothesize that adaptive planning with either computed tomography (CT) or magnetic resonance imaging (MRI) guidance may offer improved SBRT plans for postoperative gynecological cancer patients due to issues with anatomic variation between and during fractions of radiation therapy. Treatment on an MRI-guided linear accelerator with adaptive planning capabilities has been shown to significantly improve acute toxicity in the setting of prostate SBRT compared to conventional linear accelerators.10 The investigators, therefore, propose using adaptive planning with CT- or MRI-guidance to deliver 30 Gy in 5 fraction adjuvant SBRT to the pelvis for endometrial and cervical cancer patients.

Stereotactic Body Radiation Therapy (SBRT) with adaptive planning will be delivered following surgical resection of the primary tumor. Patients will receive 6.0 Gy x 5 fractions delivered once every other day. Patients will not be treated on weekends or holidays as is standard practice for radiation treatments.

Patients will be seen by the radiation oncologist within the first 3 months after completion of radiation therapy. For patients who live a distance far enough away from the University of California at Los Angeles (UCLA) where travel would be challenging for the patient, a phone or telemedicine follow-up will be considered acceptable. After this, follow-up will be performed every 6 months (+/- 4 weeks) for 5 years following completion of radiotherapy. Patients will be followed clinically and/or radiographically per physician discretion.

SCHEMA

Diagnosis of endometrial or cervical cancer

Surgical resection of primary tumor

Multidisciplinary discussion and recommendation for adjuvant radiotherapy to the pelvis

Patient enrollment in HERA clinical trial

Simulation scans to plan post-operative radiotherapy

Five fractions of radiation therapy using adaptive planning and CT or MRI guidance (6 Gy per fraction) delivered once every other day excluding weekends and holidays

Follow-up within 3 months of completion of radiotherapy

Follow-up every 6 months (+/- 4 weeks) until 5 years of completion of radiotherapy

Inclusion criteria

• Histologically confirmed endometrial or cervical cancer
• Surgical resection of the primary tumor
• International Federation of Gynecology and Obstetrics (FIGO) Stage IA-IVB endometrial cancer OR FIGO Stage IA-IIA cervical cancer that meets indications for receiving adjuvant pelvic radiotherapy alone as standard of care
• Age ≥ 18 years old
• Karnofsky performance status (KPS) ≥ 60 or Eastern Cooperative Oncology Group (ECOG) 0-2

Exclusion criteria

• Must not meet indications for receiving concurrent chemotherapy as standard of care
• Active treatment of a separate malignancy
• History of prior irradiation to the area to be treated