Encouraging Local Control With Pediatric Spatially Fractionated Radiation Therapy

Area of Science:

• Radiation Oncology
• Pediatric Oncology
• Medical Physics

Background:

• Spatially fractionated radiation therapy (SFRT) involves delivering high-dose radiation in discrete spheres, potentially improving treatment outcomes.
• While effective in adults, SFRT data in pediatric patients are lacking.
• This study addresses the need for pediatric SFRT data.

Purpose of the Study:

• To evaluate the safety and efficacy of Spatially Fractionated Radiation Therapy (SFRT) in pediatric patients.
• To analyze local control and toxicity outcomes of SFRT in a pediatric cohort.
• To explore the potential of SFRT for challenging pediatric tumors.

Main Methods:

• Retrospective chart review of pediatric patients receiving radiation therapy between 2019 and 2025.
• Inclusion criteria: at least one follow-up imaging study.
• Data collected: patient characteristics, SFRT details, outcomes, and toxicity.

Main Results:

• Five pediatric patients (median age 15.7 years) received SFRT.
• Three patients survived at last follow-up (median 13 months).
• No tumor progression or high-grade toxicity observed at SFRT sites; one wound infection noted. Two patients with pelvic osteosarcoma achieved primary tumor control but have metastatic disease. Other cases involved metastatic/recurrent Ewing sarcoma, anaplastic ependymoma, and renal cell carcinoma.

Conclusions:

• This case series presents early findings of SFRT in pediatric patients.
• SFRT demonstrated favorable local control and acceptable toxicity in this cohort.
• Further investigation of SFRT for pediatric radioresistant or recurrent tumors is warranted.