Photodynamic therapy using talaporfin sodium for grade 2/3 meningiomas: a preliminary study of safety, feasibility, and clinical outcomes

PURPOSE: Atypical and anaplastic (grade 2/3) meningiomas are associated with high recurrence rates and lack effective systemic therapies other than radiotherapy. Photodynamic therapy (PDT) using talaporfin sodium (TPS) generates selective cytotoxicity extending beyond resection margins and may improve local tumor control. Objective is to evaluate the feasibility, safety, and clinical outcomes of additional intraoperative PDT using TPS for grade 2/3 meningioma patients. METHODS: Nineteen patients with grade 2/3 meningiomas who underwent resection together with PDT at our institute between 2015 and 2025 were retrospectively analyzed. PDT was performed 22 to 26 h after intravenous TPS administration. Tumor location, pathology, Simpson resection grades, history of radiation therapy (RT), and outcomes were reviewed. RESULTS: Of the 19 patients, 18 had recurrent tumors, and 10 had prior RT. Tumor sites included skull base (8 patients), parasagittal sinus (6), convexity (2), falx (1), subcutaneous (1), and intraventricular (1). Histology revealed grade 2 (12 patients) and grade 3 (7), with Simpson I (3), II (6), III (2), and IV (8) resections. Median progression-free survival was 12.5 months, and median overall survival after PDT was 54.5 months. The prognosis was more favorable in RT- naïve patients than in those with a history of prior RT before PDT. CONCLUSION: PDT combined with resection is a safe adjunctive strategy for grade 2/3 meningiomas. Our preliminary data suggest that its efficacy is limited in post-radiation recurrences, but it may delay disease progression when applied before RT. PDT should hence be considered as a therapeutic option for grade 2/3 meningiomas.