Safety Profile and Therapeutic Efficacy of Photodynamic Therapy for Early-Stage Endobronchial Carcinoma

<bold>Background:</bold> Photodynamic therapy (PDT) is a minimally invasive endoscopic treatment for early-stage endobronchial carcinoma, particularly in multimorbid patients unsuitable for surgery. Despite its potential, limited data on its safety and efficacy have hindered widespread adoption. <bold>Methods:</bold> A retrospective analysis was conducted on all patients who received curative PDT for central early-stage endobronchial carcinoma at Ruhrlandklinik, Essen, from 2015 to 2023. The photosensitizers used were Photofrin, Chlorin E6, and Foscan. <bold>Results:</bold> The study included 36 patients (mean age: 65.4 ± 7.6 years; 19% female; mean FEV1: 51.6 ± 21.1%; mean DLCO: 46.2 ± 21.7%) with 61 lesions, of which 68.9% were multilocular. Fibrin exudation occurred in 90.6% of PDT procedures (n = 53), resulting in complete airway obstruction in 30.2% of cases within the treated area. One patient required prolonged mechanical ventilation due to severe fibrin exudation. Following the PDT procedures, bronchoscopic fibrin removal was performed in 84.9% of cases, with a median of 2 (1–4) bronchoscopies within the inpatient treatment. Phototoxic skin reactions occurred in 5.7% of cases. No postprocedural deaths occurred. Sequential biopsies revealed complete remission in 56% of lesions. Local tumor control was achieved in 88.9% of subjects, with an overall survival rate of 80.6% over a mean follow-up period of 2.3 ± 2.1 years. <bold>Interpretation:</bold> PDT demonstrates high local tumor control rates and a manageable safety profile for early-stage endobronchial carcinoma, highlighting its value as a treatment alternative for selected patients in an appropriate inpatient setting with access to endoscopic fibrin removal.