Photodynamic Therapy for Malignant Brain Tumors

Abstract

Photodynamic therapy (PDT) using talaporfin sodium together with a semiconductor laser was approved in Japan in October 2003 as a less invasive therapy for early-stage lung cancer. The author believes that the principle of PDT would be applicable for controlling the invading front of malignant brain tumors and verified its efficacy through experiments using glioma cell lines and glioma xenograft models. An investigator-initiated clinical study was jointly conducted with Tokyo Women’s Medical University with the support of the Japan Medical Association. Patient enrollment was started in May 2009 and a total of 27 patients were enrolled by March 2012. Of 22 patients included in efficacy analysis, 13 patients with newly diagnosed glioblastoma showed progression-free survival of 12 months, progression-free survival at the site of laser irradiation of 20 months, 1-year survival of 100%, and overall survival of 24.8 months. In addition, the safety analysis of the 27 patients showed that adverse events directly related to PDT were mild. PDT was approved in Japan for health insurance coverage as a new intraoperative therapy with the indication for malignant brain tumors in September 2013. Currently, the post-marketing investigation in the accumulated patients has been conducted, and the preparation of guidelines, holding training courses, and dissemination of information on the safe implementation of PDT using web sites and videos, have been promoted. PDT is expected to be a breakthrough for the treatment of malignant glioma as a tumor cell-selective less invasive therapy for the infiltrated functional brain area.

Enhanced Neurogenic Biomarker Expression and Reinnervation in Human Acute Skin Wounds Treated by Electrical Stimulation

“…Several studies have provided insights into mechanisms promoting accelerated neural differentiation and tissue regeneration (33,34). In complimentary clinical and experimental studies, documented imbalances of neuromediators found in denervated tissue are associated with conditions where delayed wound healing is common.…”

DNA repair genes in astrocytoma tumorigenesis, progression and therapy resistance

“…Among its several advantages, worthy of note are the minimum systemic adverse effects due to its double selectivity (de Freitas et al, 2017). In the past decade, the DNA repair genes in astrocytoma 9 application of PDT to treat GBM has been investigated and proven to be a promising approach, both in vitro and in vivo (Chakrabarti et al, 2013;Akimoto, 2016). In fact, the Japanese health insurance coverage has introduced, since September 2013, the PDT as a new intraoperative therapy with an indication for malignant brain tumors (Akimoto, 2016).…”

“…Firstly, it helps the surgeon to locate the whole tumor through the fluorescence emission of the photosensitizers (Fluorescence Image Guided Surgical Resection), providing higher rates of complete resection (Eljamel, 2015). Secondly, PDT increases the success of tumor ablation by eliminating its roots while normal brain tissue is spared due to a preferable accumulation of PSs in tumor cells, improving progression-free and overall survival of patients (Akimoto, 2016). However, several variables were found among the studies, including light dose and delivery method, photosensitizer utilized, and sensitivity of different tumor types, evidencing the requirement of standardized clinical trials to effectively evaluate PDT as a treatment option for GBM patients (Quirk et al, 2015).…”

Light Sources and Dosimetry Techniques for Photodynamic Therapy

“…Its use for treatment of age-related macular degeneration (3)(4)(5), actinic keratosis (6,7), esophageal cancers (8,9), and non-small cell lung cancer (10,11) has been approved by the FDA. The use of PDT in pre-clinical studies and clinical trials for skin (12)(13)(14), bladder (15), prostate (16), brain (17,18), and head and neck cancers (19)(20)(21)(22), as well as malignant mesothelioma (23)(24)(25) and gynecologic disease (26) have been reported. In contrast with chemotherapy, PDT is a highly localized treatment technique that can spare healthy cells.…”