Patent ID: 6416531
Filing Date: 2002-07-09
Classification: A61B,A61N

Abstract:
A method for destroying abnormal tissue in a tumor within a patient's body using an extended light therapy that directly applies light to less than all of the abnormal tissue in the tumor, comprising the steps of:(a) providing a plurality of light emitting probes, each light emitting probe being capable of emitting light having a characteristic emission waveband and being adapted to be at least partially inserted into said tumor, light emitted by each light emitting probe generating a fluence zone comprising a volume of tissue surrounding the light emitting probe into which light emitted by the light emitting probe penetrates along a direct path, light emitted by each light emitting probe further inducing at least one concomitant effect that generates a necrotic zone associated with each fluence zone when a corresponding light emitting probe emits light for an extended period of time, each necrotic zone extending substantially beyond the associated fluence zone; (b) determining a desired treatment zone, said desired treatment zone comprising a portion of said tumor that contains substantially all abnormal tissue that will desirably be destroyed by the extended light therapy and at least one concomitant effect associated with the extended light therapy; (c) administering a photoreactive agent to the abnormal tissue of the tumor, said photoreactive agent having a characteristic light absorption bandwidth and being preferentially absorbed by the abnormal tissue rather than by normal tissue in the patient's body; (d) implanting said plurality of light emitting probes in a spaced-apart array within said tumor, said spaced-apart array defining a pattern of the plurality of light emitting probes selected to directly apply light to less than all of the abnormal tissue, and selected such that a union of each necrotic zone associated with an implanted light emitting probe substantially corresponds to said treatment zone; (e) activating said plurality of light emitting probes to administer light to the abnormal tissue within the fluence zone around each light emitting probe; (f) continuing to administer the light emitted by the light emitting probes to the abnormal tissue for at least three hours in carrying out the extended light therapy, said light destroying abnormal tissue within each fluence zone by activating the photoreactive agent absorbed thereby; and (g) destroying abnormal tissue that is within the treatment zone but substantially beyond the fluence zone around each light emitting probe, by inducing at least one concomitant effect based upon the extended light therapy, a volume of said treatment zone being substantially greater than a combined volume of the fluence zones around each of the plurality of light emitting probes.