Prognostic Value of MRS Metabolites in Postoperative Irradiated High Grade Gliomas

Abstract

Purpose. We studied the prognostic significance of Magnetic Resonance Spectroscopy (MRS) in operated high grade gliomas. Materials and Methods. Twelve patients were treated with radiotherapy and Temozolomide. The MRS data were taken four weeks after operation (before radiotherapy) and every six months after the completion of RT. The N-acetyl aspartate, choline, creatine, and myo-inositol parameters were quantified, analyzed, and correlated to recurrence-free survival (RFS). Results. The median RFS was 26.06 months. RFS was significantly worse in elderly patients (P = 0.001) along with the higher choline/creatine ratios at either baseline (P = 0.003) or six months post Radiotherapy (P = 0.042). Median RFS was 23 months in high choline/creatine levels = 2 at 6 months after radiotherapy and 11 months for those with <2 choline/creatine levels. There was a significant correlation of maximum difference of choline/creatine ratio with RFS (rho = 0.64, P = 0.045). Conclusion. Age and choline/creatine ratio are strong independent prognostic factors in high grade gliomas.