KEY POINTS
- This prospective randomized pilot study enrolled 20 patients with locally advanced head and neck cancer receiving curative-intent concurrent chemoradiotherapy; 19 were included in the final analysis after one patient in the hydrogen gas group discontinued treatment.
- Patients received standard concurrent chemoradiotherapy alone or concurrent chemoradiotherapy plus daily hydrogen gas inhalation for 1 hour, given 1–2 hours before each irradiation session.
- Treatment consisted of intensity-modulated radiotherapy delivered in 30–33 fractions over 6–6.5 weeks, with weekly cisplatin 40 mg/m² or carboplatin at area under the curve 2.
- The hydrogen gas group showed numerically fewer chemotherapy delays (3 of 9 vs 6 of 10) and shorter median overall treatment time (48.0 vs 51.5 days), but between-group differences were not statistically significant.
- Serum metabolomics suggested exploratory changes involving uric acid and lipid-related metabolites; the hydrogen gas group had a numerically smaller reduction in uric acid, but the direct between-group comparison was not significant (p = 0.11).
CLINICAL TAKEAWAY
This is an early supportive-care and mechanistic signal, not evidence to add hydrogen gas inhalation to routine head and neck chemoradiotherapy. The toxicity trend is interesting, but the study was very small, heterogeneous, not powered for clinical outcomes, and the metabolomic pathway findings were exploratory with no external validation. Larger prospective studies with direct between-group metabolomic analysis and oncologic follow-up are needed.