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.