Apparatus and methods for providing attenuation guidance and tumor

Abstract

A system and method for providing external therapy radiation to radioactively tagged cancerous tissue via a radiation therapy machine. The system includes at least one radiation detector, e.g., a probe or gamma camera, and an analyzer, which is(are) arranged to be mounted with respect to the radiation therapy machine so that it(they) is(are) located adjacent the patient for receiving gamma rays and characteristic x rays emitted from the tagged cancerous tissue and for providing a signal representative thereof to the analyzer. The signal includes a first portion representing the characteristic x rays received from the tagged tissue and a second portion representing the gamma rays received therefrom. The portion of the signal corresponding to Compton-scattered photons is removed in the region of the full-energy gamma ray and in the region of the characteristic x ray. The analyzer uses selected portions of the signal to provide near-field information about the cancerous tissue, far-field information about the cancerous tissue, and extended field information about the cancerous tissue. This information is provided to the radiation therapy machine to control its operation so that it can irradiate the localized cancerous tissue from various directions to destroy the localized cancerous tissue, with minimal damage to adjacent viable normal tissue.