Actively Recruiting
Phase 2 Single-Arm Rectal Cancer Brachytherapy for Patients With Low-Lying Residual Adenocarcinoma After Total Neoadjuvant Therapy to Improve Organ Preservation Rates
Led by University of Colorado, Denver · Updated on 2026-04-06
44
Participants Needed
3
Research Sites
260 weeks
Total Duration
On this page
Sponsors
U
University of Colorado, Denver
Lead Sponsor
C
Cancer League of Colorado
Collaborating Sponsor
AI-Summary
What this Trial Is About
Rectal cancer patients who do not achieve a complete response to standard of care chemotherapy and radiation often require surgical resection as part of curative intent therapy. This study will evaluate whether additional "focal" radiation delivered internally (rectal brachytherapy) can provide complete responses and thus spare the requirement for surgery. The main questions are whether: 1) rectal brachytherapy is safe in this clinical treatment paradigm and if 2) rectal brachytherapy improves organ preservation (no need for surgery). The trial involves an additional MRI pelvis and sigmoidoscopy with marker placement to define high-risk residual disease for radiation planning. Subsequently, 3 outpatient brachytherapy treatments are given on a weekly basis. If a patient achieves a complete response to brachytherapy, standard of care non-operative surveillance visits are conducted with study visits aligned during the first two years following brachytherapy.
CONDITIONS
Official Title
Phase 2 Single-Arm Rectal Cancer Brachytherapy for Patients With Low-Lying Residual Adenocarcinoma After Total Neoadjuvant Therapy to Improve Organ Preservation Rates
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Willing and able to sign and date the consent form
- Willing to comply with all study procedures and available for study duration
- Adults aged 18 to 100 years
- ECOG performance status between 0 and 3
- Diagnosed with MMR-proficient low to mid rectal adenocarcinoma cT1-4 N0-2 M0 after total neoadjuvant therapy without complete tumor response
- Surgical resection offered would be abdominoperineal resection (APR) or low low anterior resection (LAR)
- Tumor restaging done 4 to 16 weeks after total neoadjuvant therapy, with at least 8 weeks if chemotherapy then chemoradiation/short course radiation was given
- Residual tumor less than 4 cm in length, less than 1.2 cm in thickness, less than 50% circumferential involvement, above the dentate line, and not involving the anal canal
- Near-complete or complete response in pelvic lymph nodes after total neoadjuvant therapy if originally cN1-2
- Time between completing total neoadjuvant therapy and starting rectal brachytherapy is between 4 and 16 weeks
- Recovered from total neoadjuvant therapy with no significant rectal incontinence at screening
- Received external beam chemoradiation between 45-56 Gy or short-course radiation of 25 Gy to rectal mucosa plus systemic chemotherapy per guidelines
- Women of child-bearing potential have a negative pregnancy test within 14 days before HDR treatment
- Sexually active men and women agree to contraception during the study and 6 months after
- Screening blood counts: platelets >50 x10^9/L, hemoglobin >8 g/dL, absolute neutrophil count >500 x10^9/L
You will not qualify if you...
- History of ulcerative colitis or Crohn's disease
- Prior pelvic radiotherapy before rectal cancer external beam radiation
- Prior colorectal surgery near the HDR brachytherapy target (except local excision)
- Uncontrolled severe illness including active infection, symptomatic heart failure, uncontrolled hypertension, unstable angina, arrhythmia, interstitial lung disease, serious gastrointestinal conditions with diarrhea, or psychiatric/social issues limiting compliance
- Life expectancy less than 3 years
- Receiving concurrent cytotoxic chemotherapy, immunotherapy, or targeted cancer agents affecting rectal cancer during the study
- Rectal cancer treatment outside standard total neoadjuvant therapy per guidelines, including radiation doses above 56 Gy or short-course radiation above 30 Gy
- Pregnant women
AI-Screening
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Trial Site Locations
Total: 3 locations
1
University of Colorado Cancer Center
Aurora, Colorado, United States, 80045
Actively Recruiting
2
University of Rochester Medical Center
Rochester, New York, United States, 14642
Not Yet Recruiting
3
Oregon Health and Sciences University
Portland, Oregon, United States, 97239
Not Yet Recruiting
Research Team
R
Radiation Therapy Group
CONTACT
A
Alex Fonder
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
NA
Model
SINGLE_GROUP
Primary Purpose
TREATMENT
Number of Arms
1
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