The application of nuclear magnetic resonance data to radiation therapy

The appropriate therapeutic modality for a patient with a malignancy depends on knowledge of the extent of the disease. If the disease is localized and suited for a course of conventional radiotherapy, delineation of the borders of the gross tumor is necessary for treatment planning. The proton nuclear magnetic resonance scan may be useful in precisely delineating the extent of the tumor due to large differences in the spin-lattice relaxation times between normal and malignant tissues. Proton NMR scanning can also be used to provide information on the relative hydrogen concentration of various tissues in situ. Knowledge of the hydrogen concentration is required to calculate the dose to an organ irradiated with a fast neutron beam.