Sep 29

SS 34 - The Automated Clinic: AI-Powered Contouring, Monitoring, and Data Extraction

286 - First Implementation of an All-In-One Solution with Fully Automatic Workflow for Rectal Cancer Based on an Integrated CT-Linac

02:15pm - 02:25pm ET

Room 257

Presenter(s)

Suqing Tian, MD, PhD - Peking University Third Hospital, Beijing, Beijing

L. Wang^1,2, X. Li^1,2, M. Yang³, Y. Pan^1,2, M. Wang^1,2, W. Zhang³, L. Jia³, R. Peng^1,2, and H. Wang^1,2; ¹Department of Radiation Oncology, Peking University Third Hospital, Beijing, China, ²Beijing Key Laboratory for Interdisciplinary Research in Gastrointestinal Oncology (BLGO), Peking University Third Hospital, Beijing, China, ³Shanghai United Imaging Healthcare Co., Ltd., Shanghai, China

Purpose/Objective(s):

To prospectively evaluate the feasibility, clinical workflow efficiency, and dosimetric performance of an integrated All-in-One (AIO) radiotherapy solution for rectal cancer, combining CT simulation, automatic segmentation, planning, and treatment on a single CT-linac platform.

Materials/Methods:

A total of 20 patients with rectal cancer underwent AIO radiotherapy using an integrated CT-linac system. The workflow included CT simulation, AI-based auto-segmentation, plan generation, online verification, and beam delivery—all executed sequentially without patient repositioning. Dosimetric parameters for targets and organs-at-risk (OARs), as well as gamma analysis results, were collected. Auto-segmentation accuracy was evaluated using Dice similarity coefficient (DSC) and average surface distance (ASD). Short-term toxicities, surgical outcomes, and tumor regression grades (TRG) were assessed at follow-up.

Results:

The entire AIO workflow was successfully completed in all patients. The median total treatment time was 37.5±6.9 minutes, with auto-segmentation and planning being the most time-consuming steps. The AIO auto-planning system achieved clinically acceptable target coverage and dose control in most cases, reflecting stable and reproducible plan quality across the cohort. The mean DSC for GTV, CTV45, and CTV50 were 0.83, 0.95, and 0.89, respectively. Gamma analysis showed excellent plan quality, with 3D pass rates exceeding 95% in all patients, and 2D pass rates across gantry angles ranging from 83.98% to 100.0% (3%/3 mm). Hematologic toxicity was the most common adverse event, with leukopenia in 55.0% of patients. Among 20 patients who completed follow-up, 19 underwent surgery and 1 achieved clinical complete response. The overall complete response (CR) rate was 15.0%, and 68.4% of surgical patients achieved TRG 0-1.

Conclusion:

The AIO approach enables a fully automated, time-efficient, and clinically feasible radiotherapy workflow for rectal cancer. High target conformity, stable plan quality, and promising early outcomes support its potential for broader clinical adoption.