Long-term follow-up results of concomitant chemoradiotherapy followed by adjuvant temozolomide therapy for glioblastoma multiforme patients. The importance of MRI information in survival: Single-center experience.

BACKGROUND AND PURPOSE: Glioblastoma multiforme (GBM) is the most common malignant primary anomaly of central nervous system. The GBM infiltrates the nearly sturctures from the initial tumor and its metastatic attribution is well known. The aim of our single-centered retrospective study was to introduce the importance of postoperative medical imaging confirmation of total tumor resection for patient with GBM combined concomitant and adjuvant chemoradiotherapy on a 10 year long patient follow up.

METHODS: From January 2006 to April 2015 we registered 59 patients with newly diagnosed GBM at the University of Kaposvár Health Center Institute of Diagnostic Imaging and Radiation Oncology. The histological diagnosis was confirmed by a proficient neuropathologist (World Health Organisation WHO; grade IV astrocytoma). According to histological status if the ECOG performance status of patients allowed it the mutidisciplinary oncoteam recommended adjuvant chemoradiotherapy all features strictly by Stupp protocol. (60 Gy dose on the gross tumor volume and 2-3 cm margin for the clinical target volume with parallel 75 mg/m2 TMZ. Four weeks after monotherapial phase patients had to recieve 6 cycles of TMZ first cycle with 150 mg/m2 up to 200 mg/m2). The irradiation was carried out by a conformal three dimensional planning system.

RESULTS: 59 patients with the median age of 63 (range 17-84) year. Our sample counted 34 male patients and 25 woman patients. 14 patients underwent gross total tumor resection while, 39 patients underwent partial resection and the rest from our sample 6 patients passed through biopsy. Statistical analysis showed a lengthier survival among males than females, with a median survival of 13 months for males and females, the OS of 26.209 for males, meanwhile 15.625 for females. However, the difference is not considerable (log-rank p=0.203). Our study found that the estimated survival of patients at least 50 years old is significantly shorter at a median survival of 12 months (log rank p=0.027) than that of patients below 50 years of age at a median survival of 23 months. The longest estimated median survival was calculated with patients of ECOG '0' condition (16 months). However, no significant difference was found in the estimated survival of patients of different ECOG conditions (log-rank p=0.146). Based on the extent of surgery, complete resection resulted in the longest average survival of 36.4 months, followed by 21.5 months among patients with biopsy, and 15.8 months among patients with partial resection. Different surgical procedures, however, did not result in significant differences in survival (log-rank p=0.059). The overal survival of patients who had complete resection confirmed by MRI compared with the overal survival of patients with residual tumor confirmed by MRI as well we can estimate that there is significant difference between these two groups (p=0,004).

CONCLUSION: Despite complex and intense treatment, recurrence is inevitable and causes relatively rapid death. In our analysis complete resection, as defined from the neurosurgeon's report and postoperative MRI, resulted in an independently significant improvement in OS. Our results are the evidences that the treatment of patients with glioblastoma multiforme in Hungary is at least on the same level as any other developed European countries.