Utility of a Simplified Irradiator for Photosensitivity Testing in Head and Neck Photoimmunotherapy

BACKGROUND/AIM: Head and neck photoimmunotherapy (HN-PIT) using cetuximab sarotalocan sodium requires post-treatment assessment for photosensitivity, but tests using direct sunlight are affected by weather and lack standardization. This study evaluated a simplified artificial irradiator for more consistent light irradiation testing. PATIENTS AND METHODS: This single-center retrospective study analyzed 16 HN-PIT treatments in 8 patients with unresectable locally advanced or recurrent head and neck cancer. On days 6-7 post-treatment, patients underwent both direct sunlight exposure and a simple irradiation test using a FLASH-PAK projector equipped with an R-60 filter to evaluate reactions around the clinically relevant 690 nm wavelength. Erythema and edema were assessed on the day of the test and 1 month later. RESULTS: No photosensitivity reactions occurred with either method, nor were delayed reactions observed. CONCLUSION: The simplified irradiator allows standardized, weather-independent photosensitivity testing after HN-PIT, although further studies are needed to confirm sensitivity and long-term reliability.