20-fraction hypofractionated radiotherapy passes noninferiority for tumor control and late toxicity in locally advanced head and neck cancer

$20-fraction hypofractionated radiotherapy passes noninferiority for tumor control and late…$

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International journal of radiation oncology, biology, physics Published June 1, 2026 Medically reviewed June 1, 2026 Study authors: Bentzen Søren M, Gupta Tejpal, Jacinto Alexandre A, Rosenblatt Eduardo, Bhasker Suman, Napoles Misle… PubMed ↗ DOI ↗ By Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development

Key Takeaway

Consider 20-fraction hypofractionated radiotherapy as a noninferior option for locally advanced head and neck cancer.

This randomized, open-label, Phase 3 noninferiority trial enrolled 792 patients with locally advanced head and neck squamous cell carcinoma across 12 centers. The study compared a 20-fraction hypofractionated (HFX) schedule delivering 55 Gy in 20 fractions, 5 fractions per week, over 4 weeks against a 33-fraction accelerated, normofractionated (NFX) 2 Gy per fraction schedule delivering 66 Gy in 2-Gy fractions, 6 fractions per week over 5.5 weeks. The primary outcomes were loco-regional tumor control and grade 3 or higher late adverse events. Noninferiority was passed for both outcomes with P = .04 for tumor control and P = .004 for late adverse events. The absolute difference between arms for overall survival, progression-free survival, loco-regional control, and grade 3+ late adverse events was ≤1.4 percentage points. Safety data regarding discontinuations and tolerability were not reported. All outcome data remained blinded at the time of reporting. The study design and population suggest potential practice relevance for radiotherapy scheduling in this setting.

Study Details

Study typeRct

Sample sizen = 792

EvidenceLevel 2

Follow-up0.9 mo

PublishedJun 2026

PMID41711624

View Original Abstract ↓

PURPOSE: Based on bioeffect modeling of published outcomes after radiation therapy for head and neck squamous cell carcinoma with various time-dose-fractionation, we hypothesized that a 20-fraction hypofractionated (HFX) schedule delivering 55 Gy in 20 fractions, 5 fractions per week, over 4 weeks would be noninferior to a 33-fraction accelerated, normofractionated (NFX) 2 Gy per fraction schedule, delivering 66 Gy in 2-Gy fractions, 6 fractions per week over 5.5 weeks with respect to both local tumor control and late adverse events. METHODS AND MATERIALS: The HYPNO (HYPo-fractionated vs NOrmo-fractionated radiation therapy for head and neck squamous cell carcinoma) trial was designed as a multicenter, pragmatic, embedded, 2-arm, unblinded, randomized controlled noninferiority trial with dual primary endpoints, loco-regional tumor control, and grade 3 or higher late adverse events with a 10% noninferiority margin for both endpoints. The trial was open for enrollment in 12 centers, each adhering to their standard of care to the extent that it was consistent with the requirements of the trial protocol. Concurrent chemoradiation therapy with 35 mg/m cisplatin weekly was permitted. RESULTS: Between March 2014 and February 2020, 792 patients were centrally randomized: 395 to HFX and 397 to NFX. Accrual closed, with all outcome data still blinded, with 792 of a planned 836 patients (94.7%) enrolled, in part due to the emerging COVID-19 pandemic. The HYPNO test arm passed the separate noninferiority tests for both loco-regional tumor control (P = .04) and grade 3+ late adverse events (P = .004). At 3 years, the absolute difference in outcome between the 2 arms was ≤1.4 percentage points for overall survival, progression-free survival, loco-regional control, and grade 3+ late adverse events. The planned subgroup analyses showed no statistically significant heterogeneity of effect estimates for loco-regional control between the 2 trial arms. CONCLUSIONS: The HYPNO test arm schedule was shown to be noninferior with respect to both loco-regional tumor control and grade 3+ late adverse events.