Phase 2 Single-Arm Rectal Cancer Brachytherapy for Patients With Low-Lying Residual Adenocarcinom… (NCT07292298) | Clinical Trial Compass
RecruitingPhase 2
Phase 2 Single-Arm Rectal Cancer Brachytherapy for Patients With Low-Lying Residual Adenocarcinoma After Total Neoadjuvant Therapy to Improve Organ Preservation Rates
United States44 participantsStarted 2026-11
Plain-language summary
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.
Who can participate
Age range
18 Years – 100 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Provision to sign and date the consent form.
. Stated willingness to comply with all study procedures and be available for the duration of the study.
. Adults (18-100 years old)
. ECOG 0-3
. Patients with MMR-proficient low-mid rectal adenocarcinoma cT1-4 N0-2 M0 who underwent total neoadjuvant therapy who have not achieved complete response (i.e. incomplete or near-complete) in the rectal primary tumor such that surgical resection, if offered presently or in the future, would be an APR or low LAR per colorectal surgeon expert opinion and central review at University of Colorado rectal tumor board. Tumor restaging will be 4-16 weeks following completion of total neoadjuvant therapy, and no sooner than 8 weeks if patients received chemotherapy followed by chemoradiation/short course radiation.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Organ preservation (no surgical requirement) of the rectum associated with complete clinical response
. Residual rectal disease must have its craniocaudal extent \<4 cm with thickness \<1.2 cm. Tumor must have \<50% circumferential involvement. Residual disease must be above the dentate line and not involving the anal canal.
. In patients with original cN1-2 disease, restaging CT and MRI after total neoadjuvant therapy must demonstrate at least near-complete response of the pelvic lymph nodes per NCCN criteria as evaluated by central review at University of Colorado rectal tumor board.
. Interval of time between completion of TNT and initiation of rectal brachytherapy must be between 4-16 weeks.
Exclusion criteria
. History of ulcerative colitis or Crohn's disease.
. Pelvic radiotherapy given prior to rectal cancer external beam radiation.
. Prior colorectal surgery in which anastomotic site is at or near HDR brachytherapy target.
. Uncontrolled intercurrent severe illness, including but not limited to, ongoing or active infection, symptomatic congestive heart failure, uncontrolled hypertension, unstable angina pectoris, cardiac arrhythmia, interstitial lung disease, serious chronic gastrointestinal conditions associated with diarrhea, or psychiatric illness/social situations that would limit compliance with study requirement, substantially increase risk of incurring AEs or compromise the ability of the patient to give written informed consent.
. Life expectancy \<3 years per provider discretion.
. Concurrent administration of any cytotoxic chemotherapy, immunotherapy, or other any targeted oncologic agent that would impact rectal cancer is not allowed during study protocol.
. If rectal cancer has been treated outside of standard total neoadjuvant therapy per NCCN guidelines, patients are ineligible for the trial. This includes if patients received external beam chemoradiation dose with prescription \>56 Gy or short-course radiation to rectal mucosa prescription \>30 Gy.