Upright pediatric radiotherapy roadmap prioritizes anesthesia safety and prospective validation

KEY POINTS

• This is a practice development report, not a clinical guideline or prospective trial, produced by an international multidisciplinary task group spanning radiation oncology, medical physics, radiation therapy, pediatric anesthesia and engineering. It evaluates upright treatment for both photon and proton radiotherapy.
• The proposed clinical rationale is strongest in children who might otherwise require repeated anesthesia but could potentially cooperate when treated in a more natural seated position. The authors explicitly state that upright radiotherapy should complement rather than replace supine treatment.
• Historical pediatric experience provides some geometric reassurance: a previous upright head and neck technique using thermoplastic immobilization reported mean intrafraction motion of approximately 0.8 mm. Contemporary pediatric evidence, however, remains extremely sparse.
• The report highlights the first modern pediatric clinical proof-of-concept described in the literature: a 4-year-old child received upright proton craniospinal irradiation under monitored anesthesia, with 18.0 Gy(RBE) in 12 fractions, a simultaneous integrated boost to 21.6 Gy(RBE) and a sequential boost to 30.6 Gy(RBE). Treatment was completed without interruption and without grade ≥2 acute toxicity.
• Anesthetized upright treatment introduces specific safety constraints. Airway visibility and access, continuous capnography, rapid immobilization release, immediate beam cessation and a predefined route to a supine rescue position should be treated as primary system-design requirements, not workflow details added after commissioning.
• Upright physiology also changes anesthetic monitoring. Because an arm blood-pressure cuff lies below brain level in a seated child, the report recommends accounting for a hydrostatic difference of approximately 2 mmHg per inch, or 1 mmHg per 1.25 cm, when considering cerebral perfusion pressure.
• Before broader pediatric adoption, the authors call for staged validation including phantom testing, upright imaging and treatment-planning accuracy, day-to-day reproducibility, intrafraction postural stability, emergency workflow testing, treatment duration, anesthesia utilization and prospective patient- and caregiver-reported experience. Three authors are employed by an upright-radiotherapy equipment company, with conflict-management procedures described in the manuscript.

CLINICAL TAKEAWAY

SOURCE

Technical Innovations & Patient Support in Radiation Oncology