P09.37 Photodynamic therapy using Talaporfin sodium and semiconductor laser combined with maximum tumor resection improves prognosis of patients with glioblastoma

Abstract

Photodynamic therapy (PDT) is a local therapy that utilizes biochemical reactions between photosensitizer, light and tissue oxygen. PDT using Talaporfin sodium has shown dramatic anti-tumor effects for various cancers including esophageal cancer. We have conducted a prospective phase II trial of PDT for malignant brain tumors between 2009 and 2012, and it was approved in 2013 in Japan. Since the approval, our institute has performed a prospective post-marketing surveillance study of PDT and we have treated 90 patients with malignant brain tumors. Here, we analyzed clinical results of this prospective study on PDT for glioblastoma patients. 41 patients (23 males and 18 females) with 16 newly diagnosed and 25 recurrent glioblastoma were treated with PDT between March 2009 and August 2015. A maximum resection of the enhanced lesion using intraoperative MRI was followed by PD laser irradiation of the cavity wall for 6 locations on average. Fractionated radiotherapy (60 Gy) and concomitant temozolomide chemotherapy were given for patients with newly diagnosed glioblastoma. The median PFS and OS were 19.6 and 31.5 months, respectively. Compared to other 76 patients with glioblastoma who underwent surgical resection in the same period in our institute, their median PFS and OS were 6.9 and 21.0 months, respectively. There was statistically significant difference in PFS between two groups (P=0.018, HR= 0.49), however there was no statistical significance in OS (P=0.08, HR=0.51), probably because of the small size of the PDT group. There was no significant adverse effect apparently related to PDT in any of the patients. Among 12 patients who recurred, only 5 (41.7%) showed local recurrence and the rest (58.3%) showed distant recurrence or dissemination, suggesting good local control by PDT. The median PFS and OS after PDT in patients with recurrent glioblastoma was 4.3 and 15.0 months, respectively. As conclusion, PDT appears to provide survival benefit for patients with both newly diagnosed and recurrent glioblastomas. A randomized clinical trial is justified and is under planning.