WASPE Sleep Adjustment for Children Aged 0-4 Years Undergoing Radiation Therapy

This is a prospective, randomized, open-label, pragmatic feasibility trial comparing a structured behavioral sleep-adjustment protocol (WASPE) with standard pharmacologic sedation to support radiotherapy (RT) delivery in children 0-4 years. Eligible patients have non-head-and-neck solid tumors indicated for external-beam RT and are randomized 2:1 to WASPE or sedation. To focus on children who typically require assistance to complete daily RT, those able to maintain treatment position without assistance are excluded.

The WASPE workflow is caregiver-guided and begins ≥3 days before RT to build sleep pressure: early wake (≈06:00-07:00), late bedtime (≈22:00-23:00), and RT scheduled 14:00-16:00 to coincide with a natural nap; familiarization with the treatment environment is encouraged. During treatment, motion is monitored with an optical surface monitoring system (OSMS) using a 5-mm threshold; if deviation exceeds the threshold and does not self-correct, irradiation is paused, the child is repositioned, and alignment is re-verified with CBCT. The control arm receives chloral hydrate 30-50 mg/kg (max 1 g) orally or rectally ~30 minutes before treatment per institutional protocol with continuous cardiorespiratory monitoring. Rescue sedation may be used as medically necessary and is recorded; caregiver-requested crossover from the sedation arm to WASPE is permitted.

Pre-treatment CBCT is registered to the planning CT at each fraction to correct set-up error. Real-time surface tracking is performed with OSMS.

The primary outcome is the per-fraction sedation-free completion rate in the WASPE arm, evaluated for non-inferiority to a prespecified performance target (95% with a 2% margin; lower 95% CI > 93%). Secondary outcomes include inter- and intrafraction displacement (CBCT/OSMS), serum IgA/IgG/IgM and growth hormone measured ≤3 days before RT and ≈7 days after completion, and safety per CTCAE v5.0 (including treatment interruptions and rescue sedation).

Inclusion criteria

• Age 0-4 years, any sex.
• Histologically confirmed malignant solid tumor indicated for external-beam radiotherapy.
• Lansky performance status ≥ 70.
• Expected survival ≥ 3 months.
• Adequate organ function within 14 days prior to enrollment, as determined by the investigator.
• Parent(s)/legal guardian(s) able and willing to follow the WASPE instructions and provide written informed consent.
• Clinical expectation that pharmacologic sedation or a structured behavioral intervention (e.g., WASPE) would otherwise be needed to complete radiotherapy.

Exclusion criteria

• Ability to maintain treatment position without assistance (i.e., child already tolerates RT without sedation/behavioral intervention).
• Head and neck tumors requiring thermoplastic mask immobilization incompatible with OSMS in our workflow.
• Sleep disorders or central nervous system dysfunction affecting sleep-wake regulation or protocol compliance.
• Clinically significant growth retardation or immunologic impairment judged by the investigator.
• Severe or uncontrolled systemic disease or infection that could interfere with participation.
• Contraindication or known allergy to chloral hydrate.
• Any other condition that, in the investigator's judgment, would preclude safe participation or reliable assessment of outcomes.