eP344 - High Dose Intraoperative Radiotherapy (HD-IORT) for Colorectal Cancer: A Single Institution Experience

Sunday, June 2, 2024

11:45 AM – 11:50 AM ET, USA

Location: Baltimore Convention Center, Room 318-320

ePoster Presenter(s)

PP

Poya Pourghaderi, DO

Colorectal fellow
Univeristy of Texas Southwestern
Dallas, TX, United States

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

Author(s)

MN

Maisa Nimer, MD

General surgery resident
UT Southwestern
Dallas, Texas, United States

Disclosure information not submitted.
SL

Scott Lacritz, MD

General surgery resident
UT Southwestern
Dallas, Texas, United States

Disclosure information not submitted.
RH

Rochelle Hartmann, APP

Colorectal Surgery Physician Assistant
UT Southwestern
Dallas, Texas, United States

Disclosure information not submitted.

Senior Author(s)

JS

Javier Salgado Pogacnik, MD

Section Chief of Colorectal Surgery
University of Texas Southwestern Medical Center
Dallas, Texas, United States

Disclosure information not submitted.

Author(s)

AG

Aurelie Garant, MD

Director of Brachytherapy
UT Southwestern
Dallas, Texas, United States

Disclosure information not submitted.
JM

Jennie Meier, MD

General surgery resident
UT Southwestern
Dallas, Texas, United States

Disclosure information not submitted.

Purpose/Background: Intraoperative radiotherapy is the delivery of a single high dose radiation at the time of surgery either through electron beam or high dose radiation. Previous studies have shown higher risks of post operative complications with high dose rate intraoperative radiotherapy (HD-IORT) compared to electron beam. They have been mixed on outcomes regarding locoregional control. We describe our quaternary institution’s experience with HD-IORT.Methods/Interventions: A retrospective chart review was performed to identify patients with colon and rectal cancer undergoing HD-IORT from 2016 to 2023 in a single institution. The patient demographics, tumor characteristics, operative findings and radiation therapy information were obtained from the chart review. Patient’s treatment modality, oncological outcomes, morbidity and mortality were evaluated.Results/Outcomes: Eleven patients were identified with colon and rectal cancer, all of whom had adenocarcinoma. 27.7% of patients had low anterior resection with HD–IORT as a part of their index surgery, 9.1% had a right hemicolectomy with HD-IORT as a part of their index surgery, and the remaining had pelvic exenteration for recurrent locoregional control. 63.6% had HD-IORT during reoperation for locoregional recurrence whereas 36.4% required HD-IORT at their index resection. A majority of patients had T4b tumors with 90.9 % including high risk features and 18.2% had lymph node involvement. 72.7% had R1 on pathology, 18.2% R0, and 9.1% R2 with 90.9% including pelvic side wall involvement. The post operative complication rate was 72.7%. Most frequent complication observe was post operative bleeding requiring transfusion (45.5%) and ileus (45.5%). There were no post operative mortalities. The median time to locoregional recurrence after HDR-IORT was 11 months.Conclusion/

Discussion: In this single institution chart review study, HD-IORT to locally advanced and recurrent colon and rectal cancer patients was associated with notable postoperative morbidity. Further multi-institutional prospective studies are needed to investigate the safety and efficacy of IORT in the management of locally advanced and recurrent colorectal malignancies.