Impact of Fluorescence-Guided Resection and Chemoradiotherapy on the Systemic Immune Response in Glioblastoma: A Kinetic Analysis of Immune Biomarkers.

The immune system plays a critical role in cancer progression and antitumor responses. Glioblastoma is an aggressive and incurable brain tumor characterized by a highly immunosuppressive microenvironment. Over the past two decades, photodynamic therapy (PDT) has been evaluated as an adjunct to fluorescent-guided resection (FGR) and chemoradiotherapy according to the STUPP protocol, for resectable glioblastomas. In addition to demonstrating the feasibility of such a procedure, two previous clinical trials (INDYGO, NCT03048240; DOSINDYGO, NCT04391062) revealed/highlighted significant systemic immune changes following treatment, including modifications in peripheral blood mononuclear cells (PBMCs) activation and cytokine secretion profiles. However, the specific contribution of PDT remains uncertain due to the combined effects of, on the one hand, PDT and, on the other hand, FGR and chemoradiotherapy. This study aims to evaluate immune parameters in a control population undergoing FGR and chemoradiotherapy only (i.e., without PDT). The objective is to distinguish the immunological impact of PDT from that of FGR and chemoradiotherapy. The results will provide a better understanding of the systemic immune modulation induced by PDT in glioblastoma.

Inclusion Criteria: * Patient male or female ≥18 years * General status (WHO) of Performance status 0, 1 or 2 * Probable glioblastoma according to clinical and radiological criteria, * whose surgical indication was given in Multidisciplinary consultation meeting (RCP) of neurooncology, * Decision to treat the patient as part of the Clinical trial also taken in neuro-oncology RCP ("Multidisciplinary consultation meeting") * Patient operable on the basis of absence of cardiopulmonary disease history; a complete medical check-up sufficient to insure a post-operative state with normal daily life * Clinical neuro-oncological monitoring and long-term MRI scheduled at the hospital CHRU of Lille, center of reference of the region * Patient able to understand and sign voluntarily Informed consent * Patient able to adhere to the visit's calendar of the study and other imperatives of the protocol * Women of child-bearing potential should benefit of an effective contraception * For patients receiving hepatotoxic therapy in the long term, this treatment must be suspended during the 24h after taking 5-ALA * Patient assigned to an health insurance Exclusion Criteria: * Contraindications to 5-ALA (Gliolan®) * Porphyria * Taking photosensitizer treatment * Severe renal or hepatic impairment * Bilirubin\> 1.5 x maximum level, Alkaline Phosphatases and transaminases (ASAT)\> 2.5 x Maximum rates * Creatinine clearance \