BACKGROUND AND AIMS
The gross total resection of a glial tumour is the aim of complex treatment and gives greater efficiency of the subsequent treatment stages, defining patients’ longevity. The impossibility of radical surgical treatment, short period of recurrency, and average longevity dictates the search for new treatment methods. Intraoperative photodynamic therapy (PDT) may lead to an increase in totality of tumour resection.1-4
The aim of the study was to increase the survival rate and duration of the relapse-free period in patients with malignant brain gliomas by using PDT as part of complex treatment.5-7
MATERIALS AND METHODS
The study included patients with glial brain tumours of supratentorial localisation with a high degree of malignancy (Grade IV glioblastoma) undergoing treatment at the Russian Neurosurgical Research Institute. The study group included 50 patients and there were 50 patients in the control group. Patients in the study group were injected intravenously 1.5 hours before the operation with a photosensitiser of the chlorine e6 group (2nd generation). After resection of the tumours, a PDT session was performed using a Latus-2.5 laser (Lotus Laser Systems, Basildon, UK) as a radiation source. The average dose was 180 J/cm2. In the postoperative period, patients in both groups received adjuvant therapy (chemotherapy and radiation therapy).8,9 Long-term results (inter-recurrence period and overall survival) were evaluated depending on the results of immunohistochemical studies (the presence of IDH mutation and MGMT).
The median survival for patients with Grade IV gliomas (MGMT+) using PDT was 23.3±4.1 months; in the control group (without PDT) the median survival was 16.5±3.3 months (p=0.0002). The median survival for patients with Grade IV gliomas (MGMT-) using PDT was 18.2±3.5 months; in the control group (without PDT) this was 11.2±2.4 months (p=0.0001). The median duration of the inter-relapse period for patients with Grade IV gliomas (MGMT+) was 13.5±2.3 months in the study group and 9.1±1.4 months in the control group (p=0.0003). The median duration of the inter-relapse period for patients with Grade IV gliomas (MGMT-) was 10.1±2.2 months in the study group and 7.0±1.1 months in the control group (p=0.0001).
PDT increased the median of the inter-relapse period and life expectancy in patients with malignant gliomas. In patients expressing MGMT, the magnitude of the inter-relapse period and life expectancy was significantly higher in the group receiving PDT.