Intraoperative radiation therapy for pediatric sarcomas and other solid tumors

Area of Science:

• Pediatric Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Intraoperative radiation therapy (IORT) is a specialized radiation technique delivering a high dose of radiation to a tumor bed during surgery.
• Pediatric solid tumors (ST) present unique challenges in treatment due to patient age and tumor biology.
• Evaluating the efficacy and safety of IORT in pediatric ST is crucial for optimizing treatment strategies.

Purpose of the Study:

• To assess local failure (LF) rates following intraoperative radiation therapy (IORT) in pediatric patients with solid tumors (ST).
• To evaluate the toxicity profile associated with IORT in this pediatric population.
• To determine the overall safety and effectiveness of IORT for local control in challenging pediatric ST cases.

Main Methods:

• A retrospective analysis of 96 pediatric patients (108 applications) treated with IORT for ST between 1995 and 2022 at a single institution.
• Local failure (LF) was calculated using the cumulative incidence function, and overall survival (OS) was determined by the Kaplan-Meier method.
• Data collected included patient demographics, tumor histology, prior treatments, IORT dose, treated area, LF, and toxicity.

Main Results:

• The cumulative incidence of local failure (LF) was 17% at 2 years and 23% at 5 years post-IORT.
• Toxicity was acceptable, with postoperative complications potentially related to IORT observed in 16% of patients.
• Common histologies included rhabdomyosarcoma, Ewing sarcoma, and Wilms tumor; 54% were treated with upfront IORT due to difficult circumstances.

Conclusions:

• Intraoperative radiation therapy (IORT) demonstrates efficacy in achieving local control for pediatric solid tumors (ST), with less than a quarter experiencing local failure.
• The study highlights IORT as a safe and effective technique, particularly for pediatric patients with challenging tumor presentations.
• This analysis represents a significant contribution to understanding the long-term outcomes of IORT in pediatric oncology.