High-dose rate intraoperative radiation therapy for pediatric solid tumors

Area of Science:

• Pediatric Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Investigated the feasibility and safety of high-dose rate intraoperative radiation therapy (IOHDR) in 16 pediatric patients with solid tumors.
• IOHDR was delivered using a remote afterloader, with patients receiving multiagent chemotherapy and some prior external beam radiation therapy.

Purpose of the Study:

• To evaluate the safety and efficacy of IOHDR as a treatment modality for pediatric solid tumors.
• To assess local control, metastasis-free survival, and overall survival rates following IOHDR.

Main Methods:

• Included 16 pediatric patients with various solid tumors (Ewing's sarcoma, rhabdomyosarcoma, etc.).
• IOHDR was administered to the abdomen, chest-wall/thoracic cavity, and pelvis, with prescribed doses of 1200 cGy.
• Patients received chemotherapy, and some had prior external beam radiation therapy or surgical resection attempts.

Main Results:

• At a median follow-up of 18 months, 2-year actuarial rates for local control, metastasis-free survival, and overall survival were 61%, 51%, and 54%, respectively.
• Patterns of failure included local, distant, and combined local + distant recurrence.
• Complications included abscess, delayed wound healing, and cytopenia. Survival outcomes varied, with some patients alive with no evidence of disease and others deceased due to disease, other causes, or treatment.

Conclusions:

• IOHDR demonstrated potential for improving local control in pediatric solid tumors.
• The ability to precisely target radiation with IOHDR minimizes dose to surrounding normal tissues, making it a valuable adjunct to external beam radiation therapy.
• IOHDR can be safely integrated into the management of pediatric solid tumors, balancing high radiation doses with the risk of late effects.