Rednet News, August 24 (Correspondent: Long Hong) — Recently, the gastrointestinal surgery team led by Ouyang Jun at The First Affiliated Hospital of University of South China, working with the radiotherapy team led by Manbo Cai from the Department of Oncology, successfully performed a 3D laparoscopic radical resection for rectal cancer (Dixon procedure). Using HC-IORT, the teams completed the hospital’s first rectal cancer intraoperative radiotherapy procedure with an electron beam spherical applicator, seamlessly integrating surgical resection with IORT.

Rectal tumors are located within the narrow, deep pelvis. In some high-risk patients, subclinical disease that is difficult to detect visually may remain even after all visible tumor has been surgically removed, creating a risk of local recurrence. IORT can deliver a localized boost to areas at high risk of recurrence during surgery. Normal tissues can be displaced outside the irradiation field for protection, allowing potential residual disease to be targeted precisely. When combined with surgery and postoperative external beam radiotherapy, this approach may further improve surgical benefit and the likelihood of cure.

During this procedure, Ouyang Jun’s team used 3D laparoscopy to complete precise radical resection of the rectal tumor. After tumor removal, Manbo Cai’s radiotherapy team identified the target area at high risk of recurrence under direct laparoscopic visualization. Because the pelvic surgical bed may be curved, recessed or otherwise irregular, a conventional planar applicator may not conform adequately or match the intended treatment area. The clinical team therefore selected a 50 mm electron beam spherical applicator. Its curved surface conformed closely to the complex deep-pelvic surgical bed, reducing geometric mismatch and helping deliver an adequate, uniform dose to the tumor bed. The prescribed dose was 15 Gy using a 9 MeV electron beam, with an actual beam-on time of only 4.91 minutes.

Precise resection and targeted irradiation were completed during the same operation, providing a new technical approach to local treatment of high-risk rectal cancer in the deep pelvis. The successful procedure represents another advance in multidisciplinary rectal cancer care at the hospital and may help strengthen comprehensive treatment capabilities for gastrointestinal tumors in southern Hunan.