CLINICAL APPLICABILITY OF HUMAN IN-VIVO LOCALIZED P-31 MAGNETIC-RESONANCE SPECTROSCOPY OF BONE AND SOFT-TISSUE TUMORS

Background: Magnetic resonance imaging (MRI) is of restricted value fo r the in vivo characterization of tumor types. The applicability of ph osphorus-31 (P-31) magnetic resonance spectroscopy (MRS) in the diagno sis of bone and soft tissue tumors is unknown. Methods: A total of 191 consecutive patients (85 females and 106 males; mean age 41 years, ra nge 1-80) with a well-defined bone or soft tissue tumor on MRI were an alyzed for additional P-31 spectroscopy. Histology and/or cytology was obtained from all tumors. Because of low sensitivity of the P-31 nucl eus and the contamination of surrounding tissue, only large, superfici ally located tumors accessible to the surface coil could be accepted f or MRS. Results: Twenty-one patients (11%) could be included in the st udy. From this remaining group only 12 studies (57%) produced spectra with well resolved phosphorus peaks and an acceptable signal-to-noise ratio. However, these spectra did not allow differentiation between th e benign and malignant nature of the lesions. The other 9 studies show ed spectra with poor signal intensities and/or poorly defined peaks, m aking tumor differentiation impossible. Conclusion: Only 6% of the bon e and soft tissue tumors produced well defined spectra, which implies that localized P-31 MRS cannot be considered as a routine technique in the diagnostic and treatment evaluation of bone and soft tissue tumor s.