EP713 - Intraoperative Radiotherapy in the Management of Locally Advanced and Recurrent Colorectal Cancer: A Retrospective Study

Monday, May 12, 2025

10:36 AM – 10:41 AM PT

ePoster Presenter(s)

Ali Alipouriani, MD

Clinical Research Fellow
Colorectal Surgery Department, Digestive Disease Institute, Cleveland Clinic Foundation
Department of colorectal surgery, Cleveland Clinic Foundation
Cleveland, Ohio, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Author(s)

Salih Karahan, MD

Research Fellow
Cleveland Clinic Department of Colorectal Surgery
Cleveland Heights, Ohio, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.
SA

Sudha R. Amarnath, MD

Staff Physician
Cleveland Clinic Foundation-Main Campus
Cleveland, Ohio, United States

Disclosure information not submitted.
JM

Jacob A. Miller, MD

Assistant Professor
Radiation Oncology, Cleveland Clinic
Cleveland, Ohio, United States

Disclosure information not submitted.
Michael A. Valente, DO

Associate Professor of Surgery
Cleveland Clinic
cleveland, Ohio, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.
Scott R. Steele, MD, MBA

President, Cleveland Clinic, Main Campus Submarket and Rupert B. Turnbull M.D., Endowed Chair in Colorectal Surgery
Cleveland Clinic
Cleveland, OH, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.
David Liska, MD

Associate Professor, Chair
Department of Colorectal Surgery, Cleveland Clinic
Cleveland Clinic, Cleveland, Ohio
Cleveland, Ohio, United States

Disclosure information not submitted.

Senior Author(s)

EG

Emre Gorgun, MD, MBA

Vice Chair, Department of Colorectal Surgery
Cleveland Clinic Foundation-Main Campus
Cleveland, Ohio, United States

All of the relevant financial relationships listed below have been mitigated.
This individual has no relevant relationships with ineligible companies.

All of the relevant financial relationships listed below have been mitigated.

Ali Alipouriani, MD: This individual has no financial relationships with ineligible companies.

Salih Karahan, MD: This individual has no financial relationships with ineligible companies.

Michael A. Valente, DO: This individual has no financial relationships with ineligible companies.

Scott R. Steele, MD, MBA: This individual has no financial relationships with ineligible companies.

Emre Gorgun, MD, MBA: This individual has no relevant relationships with ineligible companies.

Image or Table (Do Not add text here):

Purpose/Background: Colorectal cancer is a leading cause of cancer mortality and morbidity. Patients with locally advanced colorectal cancer (LACC) or locally recurrent colorectal cancer (LRCC) are at a higher risk of local recurrence despite multimodal treatments, including surgery or chemoradiation therapy. They are surgical challenges for oncological resections such as major vessels, bones, soft tissue (e.g. abdominal wall) in case of locally advanced cases. Intraoperative radiotherapy (IORT) offers direct high-dose radiation to the tumor bed during surgery, potentially reducing local recurrence while preserving surrounding healthy tissues. The role of IORT in improving local control and survival in this patient population remains under investigation.

Methods/Interventions: This retrospective cohort study evaluated IORT outcomes in patients with LACC and LRCC treated between January 1, 2013, and December 30, 2023. Inclusion criteria encompassed patients who underwent surgical resection with IORT. Data on demographics, tumor characteristics, treatment details, and clinical outcomes were collected. Descriptive statistics summarized baseline characteristics, and statistical tests (e.g., chi-square, t-tests) were used to assess differences in recurrence rates, survival, and complications between the LACC and LRCC groups.

Results/Outcomes: A total of 75 patients were included, 23 (31%) patients in the LACC group and 52 (69%) in the LRCC group, with a median age of 59 years in both groups. The majority of patients were male: 12 (52.1%) in the LACC group and 32 (61.5%) in the LRCC group. Tumor location was predominantly in the rectum (LACC: 82.6%, LRCC: 65.4%), and adenocarcinoma was the most common histology (LACC: 82.6%, LRCC: 84.6%). There was no statistically significant difference in tumor stage or metastasis between the two groups. Local recurrence was significantly higher (LRCC: 21% vs LACC: 3%, p=0.03) although distant metastasis rates were similar (LACC: 17.3% vs LRCC: 38.5%, p=0.9). Wound dehiscence (LACC: 30.4% vs LRCC: 25%, p=0.7) and pelvic abscess (LACC: 8.7% vs LRCC: 13.5%, p=0.7) were the predominant complications within the first 90 days after IORT, whereas radiation-induced fibrosis emerged as the most frequent issue beyond 90 days (LACC: 4.3% vs LRCC: 13.5%, p=0.4). With a median follow-up time of one, three, and five years, overall survival rate were not significantly different between two groups.

Conclusion/Discussion: Intraoperative radiotherapy improves local control in LACC, particularly in cases with anatomical challenges like major vessels, bones, or soft tissue involvement. While it doesn't affect distant metastasis or overall survival, our data suggest IORT may play a key role in reducing local recurrence in advanced colorectal cancer.