OncoMatch/Clinical Trials/NCT07786493

HDR Endorectal Brachytherapy With 3D-Printed Guidance and Local Shielding for Rectal Cancer Organ Preservation

Official title: A Prospective Single-Arm Phase II Study of Pelvic External Beam Radiotherapy Followed by HDR Endorectal Brachytherapy Combined With a 3D-Printed Individualized Guide Template and Tungsten-Alloy Local Shielding for Organ Preservation in Inoperable Localized Rectal Cancer

Is NCT07786493 recruiting? Yes, currently enrolling (Oct 2026). This NA trial studies non-drug interventions for rectal cancer, adenocarcinoma.

This prospective, single-center, single-arm phase II study will evaluate the efficacy, safety, and technical feasibility of an organ-preserving radiotherapy strategy for patients with localized rectal adenocarcinoma who are medically inoperable, decline radical surgery, or are considered technically unresectable without distant metastases. Participants will receive pelvic external beam radiotherapy followed by high-dose-rate (HDR) endorectal brachytherapy. Concurrent capecitabine may be given during external beam radiotherapy to participants who are considered able to tolerate chemotherapy. During HDR brachytherapy, all participants will be treated using a patient-specific 3D-printed guide template and individualized tungsten-alloy local shielding. The guide template is designed to improve applicator positioning and treatment reproducibility, while the local shielding is intended to reduce radiation exposure to non-target rectal wall. The study will enroll 50 participants. The primary objectives are to evaluate the 12-month clinical complete response rate and the technical completion rate of the HDR brachytherapy platform. Secondary assessments include organ preservation, local regrowth, survival outcomes, treatment-related toxicity, quality of life, and anorectal function.