Outcomes of Near-Infrared Photoimmunotherapy for Head and Neck Cancer: A Single-Center Retrospective Study

BACKGROUND/OBJECTIVES: Near-infrared photoimmunotherapy (NIR-PIT) represents a treatment approach for patients with locally advanced or recurrent head and neck cancers who are unsuitable for surgery post-standard therapy. Since its introduction in Japan in January 2021, NIR-PIT has been available exclusively under the national health insurance system, resulting in limited real-world clinical practice data. This study evaluated the association between NIR-PIT and overall survival (OS) in clinical practice. METHODS: This single-center retrospective study included 45 patients with head and neck cancer who were not amenable to surgical resection owing to advanced local disease or regional recurrence without distant metastasis and who underwent NIR-PIT or systemic pharmacotherapy between January 2021 and April 2025. The primary endpoint was OS. RESULTS: Twenty-two and 23 patients received NIR-PIT and pharmacotherapy, respectively. In the NIR-PIT group, irradiation was delivered to primary tumors in 20 patients, cervical lymph node lesions in one, and both primary and lymph node lesions in one. The median OS was 35 and 8 months, with median follow-up of 40 and 49 months in the NIR-PIT and pharmacotherapy groups, respectively. Among the NIR-PIT-eligible patients, 22 and 10 were treated with NIR-PIT and pharmacotherapy, respectively. The median OS was 35 and 8 months, with median follow-up of 40 and 24 months in the NIR-PIT and pharmacotherapy groups, respectively. CONCLUSIONS: NIR-PIT was independently associated with improved OS in patients with unresectable recurrent or metastatic head and neck cancer without distant metastasis. Prospective multicenter studies are warranted to validate these findings.