Photodynamic therapy of malignant gliomas

Introduction. Malignant gliomas are among the most lethal and difficult to treat types of tumors, given their aggressiveness and infiltrative nature of growth, as well as localization. Photodynamic therapy (PDT) is a promising method and direction, and is an intraoperative local laser therapy used after surgical removal of the tumor. Purpose of the study. To analyze the clinical outcomes and prognosis in patients with glioblastoma treated with PDT compared to patients who did not receive it. Material and methods. This retrospective study included patients diagnosed with glioblastoma treated at the Polenov Russian Scientific Research Institute from January 2011 to December 2017. PDT included irradiation of the postoperative resection cavity with a 662 nm semiconductor laser after intravenous injection of Photoditazine. The main efficacy indicators were recurrence rate and survival time, which were compared in the PDT and non-PDT groups. Univariate and multivariate analyses were used to determine prognostic factors. In addition, adverse events and prognostic factors were analyzed in the PDT group. Results. The PDT and non-PDT groups included 39 and 55 patients, respectively. The local recurrence rate was significantly lower in the PDT group than in the non-PDT group (50.8 % vs. 84.1 %), and the distant recurrence and dissemination rates were also lower in the PDT group than in the non-PDT group (20.5 % vs. 44.3 %). Median progression-free survival and overall survival were significantly higher in the PDT group than in the non-PDT group (recurrence-free survival: 11.9 vs. 7.6 months, respectively, and overall survival: 21.5 vs. 13.1 months, respectively). Multivariate analysis of the PDT groups showed that younger age was an independent prognostic factor. Conclusion. PDT with Photoditazine provided effective local control with minimal side effects. The survival time of patients treated with PDT was significantly higher than that of patients who did not receive PDT.