Stereotactic Pelvic Adjuvant Radiation Therapy in Cancers of the Uterus.

Stereotactic Pelvic Adjuvant Radiation Therapy in Cancers of the Uterus: A Phase 1 Pilot Study (SPARTACUS)

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.

Study Overview

• Status: Completed
• Conditions: Carcinosarcoma; Endometrioid Adenocarcinoma; Clear Cell Carcinoma; Serous Carcinoma; Dedifferentiated Carcinoma
• Intervention / Treatment: Radiation: Image-guided adjuvant pelvic radiotherapy

• Study Type: Interventional
• Enrollment (Actual): 23
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • London, Ontario, Canada, N6A 5W9
      • London Regional Cancer Program

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assess the acute urinary and bowel toxicities	Acute urinary and bowel toxicities associated with adjuvant SBRT treatment in the setting of high-risk endometrial cancer will be assessed using the Common Terminology Criteria for Adverse Events.	Baseline to 2 years post-treatment.

Collaborators and Investigators

• Sponsor: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
• Investigators: Principal Investigator: David D'Souza, M.D., London Regional Cancer Program

Study record dates

Study Major Dates

• Study Start (Actual): August 26, 2020
• Primary Completion (Actual): May 2, 2024
• Study Completion (Actual): May 14, 2024

Study Registration Dates

• First Submitted: June 23, 2020
• First Submitted That Met QC Criteria: July 2, 2020
• First Posted (Actual): July 7, 2020

Study Record Updates

• Last Update Posted (Actual): August 1, 2025
• Last Update Submitted That Met QC Criteria: July 29, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Endocrine System Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Neoplasms by Histologic Type; Uterine Diseases; Genital Diseases, Female; Neoplasms, Glandular and Epithelial; Adenocarcinoma; Ovarian Diseases; Adnexal Diseases; Genital Neoplasms, Female; Gonadal Disorders; Sarcoma; Neoplasms, Connective and Soft Tissue; Cystadenocarcinoma; Neoplasms, Cystic, Mucinous, and Serous; Neoplasms, Complex and Mixed; Endometrial Neoplasms; Ovarian Neoplasms; Carcinoma; Cystadenocarcinoma, Serous; Carcinosarcoma; Carcinoma, Endometrioid; Adenocarcinoma, Clear Cell; Uterine Neoplasms; Adenomyoepithelioma
• Other Study ID Numbers: SPARTACUS

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No