Cs-131LDR Brachytherapy for Organ-Preserving Irradiation for Recurrent Cervical and Endometrial Cancer

Phase II Clinical Trial of Cesium-131 Low-dose Rate Interstitial Brachytherapy as an Organ-preserving Irradiation Technique for Recurrent Cervical and Endometrial Cancer

This clinical trial studies how well cesium-131 low-dose rate interstitial brachytherapy works as an organ-preserving radiation technique in the treatment of patients with cervical and endometrial cancer that has come back in the vagina after a period of improvement following pelvic radiation therapy (vaginal recurrence). In cervical and endometrial cancer patients with vaginal recurrence following pelvic radiation therapy, the only curative option involves a major surgical procedure which removes all the contents of the pelvic cavity, such as the uterus, cervix, bladder, rectum, vagina, and vulva. This procedure is complex and comes with many side effects; therefore, a need remains to improve radiation treatment techniques so radiation therapy can be offered as an alternative treatment option for these patients. Cesium-131 low-dose rate interstitial brachytherapy is a form of internal radiation therapy called brachytherapy. It uses grain-of-rice-sized radioactive seeds implanted directly into or near where the tumor has returned. The implanted seeds give off radiation to kill tumor cells for only a short time after they are placed. Most of the radiation is gone within a few weeks. The seeds stay in the body permanently, but they become inactive quickly. Cesium-131 low-dose rate interstitial brachytherapy may be an effective organ-preserving radiation technique for the treatment of cervical and endometrial cancer patients with vaginal recurrence following pelvic radiation therapy

Study Overview

• Status: Not yet recruiting
• Conditions: Gynecologic Cancer
• Intervention / Treatment: Device: Cesium-131 Low Dose Radiation (LDR)

• Study Type: Interventional
• Enrollment (Estimated): 10
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Heather Pavlik; Phone Number: 8593232354; Email: heather.schroer@uky.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients must have histologically or cytologically confirmed vaginal recurrence of endometrial (endometrioid adenocarcinoma, uterine serous, carcinosarcoma, clear cell) or cervical (squamous, adenosquamous, or adenocarcinoma) cancer and prior history of pelvic radiation.
• Patients must have vaginal recurrence that is amenable to cesium implant for salvage
• Patients must have a vaginal lesion that is measurable according to RECIST 1.1 criteria; that is, at least 1 cm upon measurement by CT, or MRI if the patient cannot have a CT with contrast or lesion is not visualized on CT scan, or measurement by calipers if the lesion is not seen on CT or MRI.
• Patients must have previous external beam radiation treatment to the pelvis for the uterine cervix or endometrial malignancy that has recurred to be eligible for this study, so long as the prior exposure does not exceed tolerance at the discretion of the treating physician.
• Gynecologic Oncology Group performance status of 0, 1, or 2 (see Appendix A).
• There are no minimum organ/marrow function requirements because patients will not be receiving systemic therapy.
• Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

• Patients who have another concurrent, active invasive malignancy or have had a prior invasive malignancy diagnosed within the last three years, with the following two exceptions: [a] non-melanoma skin cancer and/or [b] prior in situ carcinoma of the cervix and/or [c] in situ bladder cancer.
• Patients who have metastatic or regional lymph node metastases who have radiographic evidence of disease at time of study enrollment. Patients who have had metastasis or lymph nodes previously treated without radiographic disease at time of study enrollment may be considered at discretion of the treating radiation oncologist.
• Receipt of epoetin alpha (Procrit, Epogen) within 1 month of study screening.
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to Cesium-131 implant or other agents used in this study.
• Pregnant women are excluded from this study because radiation is a known teratogen. Patient must agree to use two forms of birth control if they are of child-bearing potential. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, throughout duration of active treatment and for two months after completion of radiation. Should a woman become pregnant or suspect she is pregnant while she is participating in this study, she should inform her treating physician immediately.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cesium-131 Brachytherapy	Device: Cesium-131 Low Dose Radiation (LDR); Placed one time by radiation oncologist under appropriate level of sedation as determined by anesthesiologist.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of participants with organ preservation	Organ preservation rate is defined as avoidance of pelvic exenteration and organ sacrificing surgeries including total vaginectomy, cystectomy and anterior perineal resection.	1 Year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression-free survival (PFS)	PFS using RECIST 1.1	1 Year
Local Control Rate	Local control using combination of imaging and physical exams	1 Year

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tumor Hypoxia Inducible Factor (HIF-1a) Marker Expression	Assessment of tumor hypoxia marker expression using HIF-1a expression in recurrent tumors previously treated with radiation.	2 Years
Radiosensitivity Marker Expression for Breast Cancer Gene (BRCA)	Assessment of radiosensitivity marker expression using BRCA in recurrent tumors previously treated with radiation.	2 Years
Radiosensitivity Marker Expression for Mismatch Repair (MMR)	Assessment of radiosensitivity marker expression using MMR in recurrent tumors previously treated with radiation.	2 Years
Prognostic Marker Expression p16	Assessment of prognostic marker expression using p16 in recurrent tumors previously treated with radiation.	2 Years

Collaborators and Investigators

• Sponsor: Denise Fabian

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): May 1, 2029
• Study Completion (Estimated): May 1, 2030

Study Registration Dates

• First Submitted: April 30, 2026
• First Submitted That Met QC Criteria: June 1, 2026
• First Posted (Actual): June 8, 2026

Study Record Updates

• Last Update Posted (Actual): June 8, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Cesium
• Additional Relevant MeSH Terms: Therapeutics; Radiotherapy
• Other Study ID Numbers: MCC-25-GYN-12

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes