The results of postoperative irradiation in malignant glioma patients

Abstract

Aim

The purpose of our study was to conduct a retrospective analysis of malignant glioma patients treated with postoperative radiotherapy in order to assess the clinical outcome and identify prognostic factors which may alter the prognosis.

Materials/Methods

We have retrospectively reviewed the medical records of 107 patients with histologically confirmed cerebral high grade gliomas (HGG) treated with postoperative radiotherapy from November 1997 to December 2002 at the Department of Radiotherapy of the Holycross Cancer Centre in Kielce. The total dose varied from 20 Gy in 5 fractions to 62 Gy in 31 fractions. The overall survival (OS) and the progression free survival (PFS) were calculated by using the actuarial method according to Kaplan and Meier. A multivariate analysis was made using the Cox regression model to identify independent prognostic factors. The following factors were studied for the prognostic significance for OS and PFS: histology, sex, age, the WHO performance status and the neurological deficit status, the size and localization of the tumour before surgery, the extent of the resection, the time from the operation to the start of the irradiation, the total dose of radiotherapy and the response to treatment three months from the end of radiotherapy.

Results

The overall survival (OS) was 0.38 and 0.13 at one and two years, respectively, and the progression free survival (PFS) was 0.13 and 0.06 at one and two years, respectively, for the whole group of the postoperatively irradiated patients. In the multivariate analysis: histopathology, age, performance and the neurological status before the onset of radiotherapy, the total dose of irradiation and the response to the treatment observed three months from the end of radiotherapy were found to be significant prognostic factors for the overall survival, while histopathology, age, performance and the neurological status at the beginning of the irradiation and the total dose of the radiotherapy were found to be significant prognostic factors for the progression free survival.

Conclusions

The prognosis for high-grade glioma patients remains poor. The combined treatment, operation and radiotherapy, resulted in the overall survival of 0.38 at one year and 0.13 at two years and the progression free survival of 0.13 at one year and 0.06 at two years in the study group. In the multivariate analysis: histopathology, age, performance and the neurological status before the onset of radiotherapy, the total dose of the irradiation and the response to treatment observed three months from the end of radiotherapy were found to be significant prognostic factors influencing the overall survival, while histopathology, age, performance and the neurological status at the beginning of the irradiation, the total dose of radiotherapy were found to be significant prognostic factors influencing the progression free survival. The assessment of the prognostic factors is very important, because it is a guide to the treatment selection by clinicians.