(31)PHOSPHORUS MAGNETIC-RESONANCE SPECTROSCOPY IN THE ASSESSMENT OF HEAD AND NECK TUMORS

Purpose: (31)Phosphorus magnetic resonance spectroscopy (P-31-MRS) pro vides biochemical information in a noninvasive way, The aim of this wo rk was: (a) to characterize the P-31 spectrum of advanced head and nec k tumors, and (b) to evaluate the spectral changes after treatment and to correlate them with the pathologic response. Methods and Materials : A total of 20 patients diagnosed with advanced head and neck tumors and 7 healthy controls participated in the study, The tumor mass and i ts contralateral side were studied by means of P-31-MRS before and aft er treatment, Neck muscles of a control group were also studied, Resul ts: Tumors presented ratios of phosphomonoesters (PME), phosphodiester s (PDE), and inorganic phosphate (Pi) with respect to the adenosine tr iphosphate (ATP), significantly higher and a PCr (phosphocreatine)/ATP ratio lower than the neck muscle of volunteers or the contralateral s ide, The PDE/ATP and PME/ATP ratio values obtained before therapy were similar, independent of the later response to treatment, However, whe n there was a complete response, the ratios measured after treatment w ere decreased, Conclusion: These results show the existence of signifi cant differences between the (31)phosphorus spectrum of tumors and nec k muscle, but also between the tumors and their contralateral sides. M oreover, P-31-MRS is able to detect metabolic changes after a complete response, These results suggest that P-31-MRS would be useful in the evaluation of the clinical response of head and neck tumors, (C) 1998 Elsevier Science Inc.