Mri guided hyperthermia surgery

Abstract

An MRI guided surgical apparatus includes a heat source formed by a laser and an optical fiber carrying the heat energy into a part to be coagulated by hyperthermia with an end reflector to direct the energy in a beam to one side of the fiber end. The fiber includes a reinforcing sleeve along its length to prevent bending and twisting. The sleeve is mounted in a shielded, Piezo-electric motor which causes movement of the fiber longitudinally of its axis to move the end within the part and rotation of the fiber about its axis to cause the beam to rotate about the axis. A rigid elongate cannula is arranged for insertion to a position at the part of the patient having a bore for receiving a portion of the fiber adjacent the outlet end in sliding engagement therein such that the end can pass through the cannula into engagement with the part of the patient. A part of the sleeve projecting beyond the cannula is rigid and a further part connecting to the motor is stiff but less rigid. A magnetic resonance imaging system is arranged to generate a series of output signals over a period of time representative of temperature in the part as the temperature of the part changes during that time. The heat source is controlled in heat energy applied and location and orientation of the beam to continue the heating at a respective area in the part until the temperature at a selected location in the part normally at the boundary of a tumor reaches the required hyperthermic temperature as monitored whereupon the heating in the area is halted.