[Nuclear magnetic resonance in oncologic radiotherapy].

The possibilities of utilizing Nuclear Magnetic Resonance in Radiation Oncology are examined, on the basis of information provided by spectroscopy (MRS), studies on the tissues characterization of tumors, and preliminary practical application of imaging (MRI) to radiation therapy. MRS affords information on the bioenergetics of the tumor cells, and on the biochemical changes induced by ionizing radiation; further, some results of clinical importance were obtained in "monitoring" tumor response to radiation therapy and chemotherapy. Tissue characterization of normal tissues and of tumor is analyzed; technical factors, morphological elements, and structural elements are considered. Morphological elements include anatomical recognition, clinical and radiological evaluation, appraisal of the peritumoral tissues, and analysis of inhomogeneities. Among structural elements are considered some methods suitable to achieve a full evaluation of tissue characterization of tumors, on the basis of an appropriate employment of sequence parameters. Practical application of MRI on radiotherapy of tumors comprises staging procedures, contribution to the selection of differentiated radiation volumes for radiotherapy planning, and new data on the evaluation of biological effects of ionizing radiation on normal tissues of patients.