Advanced technology has enabled radiation oncologists to more accurately and precisely target radiation to areas at risk while maximally sparing healthy tissue. Furthermore, there is growing evidence demonstrating both safety and efficacy for SBRT. We propose that these advantages are translatable to the adjuvant treatment of endometrial cancer. We submit that a prescription dose of 30 Gy in 5 fractions, which equates to a 2 Gy equivalent dose (i.e an EQD2) (α/β = 10 Gy) of 48 Gy, compares favorably to the EQD2 delivered standardly for adjuvant treatment (44.25 Gy via 45Gy/25Fx; 50 Gy at vaginal surface for vault brachytherapy) and therefore should be effective and safe dose in the adjuvant setting. Through precision delivery and careful dosimetry the treatment should be safe and well tolerated with minimal impact on patient quality of life.

Inclusion Criteria:

• Patients, who have undergone hysterectomy for curative intent, with histologically confirmed endometrioid adenocarcinoma, serous or clear cell carcinoma, or carcinosarcoma or dedifferentiated carcinoma

• Patient is a candidate for adjuvant pelvic radiation (+/- vault brachytherapy), meeting one of the following conditions:

  • High grade histology OR
  • Outer-half myometrial invasion and FIGO grade 1-2 OR
  • FIGO stage II - IIIC1 (all gross nodal disease must be resected)

• Patient is willing and able to give informed consent to participate in this clinical trial.

• Age ≥18 years.

• Patients who are to receive adjuvant systemic therapy in addition to pelvic radiotherapy will be eligible provided that there is at minimum a 3-week interval between any radiation treatment and chemotherapy treatments. Adjuvant systemic therapy may be given before or after radiation treatment.

• Patient must be willing and able to complete the QLQ-C30 questionnaire with EN-24 companion as described in the study protocol.

• Primary language of the patient must be English or, if a patient's primary language is not English, they are still able to participate provided the QLQ-C30 and EN-24 is available in their primary language.

Exclusion Criteria:

• Patient has had prior pelvic radiotherapy.
• Patient has received neo-adjuvant systemic therapy
• Patient has a contraindication to pelvic radiotherapy, such as but not limited to a connective tissue disease or inflammatory bowel disease.
• Patient has a contraindication to iodinated CT contrast.
• Patient has a hip prosthesis.