Image-guided therapy of a tissue

Abstract

Image-guided therapy of a tissue can utilize magnetic resonance imaging (MRI) or another medical imaging device to guide an instrument within the tissue. A workstation can actuate movement of the instrument, and can actuate energy emission and/or cooling of the instrument to effect treatment to the tissue. The workstation and/or an operator of the workstation can be located outside a vicinity of an MRI device or other medical imaging device, and drive means for positioning the instrument can be located within the vicinity of the MRI device or the other medical imaging device. The instrument can be an MRI compatible laser probe that provides thermal therapy to, e.g., a tissue in a brain of a patient.

What is claimed is: 
     
         1 . (canceled) 
     
     
         2 . A side-firing energy emission probe comprising:
 a housing;   an optical fiber disposed within the housing, wherein
 the optical fiber includes a sheathed portion and an unsheathed portion, the unsheathed portion disposed at least adjacent to a distal end of the optical fiber, and the unsheathed portion of the optical fiber having at least one facet upon a longitudinal surface; and 
   a cooling tube disposed within the housing, wherein a distal opening of the cooling tube opens to a cooling chamber region of the distal end of the housing to supply a cooling gas to cool an exterior surface of the distal end of the housing during energy emission by the optical fiber; wherein   the optical fiber is configured to emit energy via the at least one facet at an angle to a longitudinal axis of the optical fiber through a transparent region of the housing.   
     
     
         3 . The side-firing energy emission probe of  claim 2 , wherein the angle is substantially perpendicular to the longitudinal axis of the optical fiber. 
     
     
         4 . The side-firing energy emission probe of  claim 2 , wherein the gas coolant is medical grade carbon dioxide. 
     
     
         5 . The side-firing energy emission probe of  claim 2 , wherein the coolant gas is pressurized gas, and the coolant gas expands within the cooling chamber region to provide Joule-Thomson cooling. 
     
     
         6 . The side-firing energy emission probe of  claim 2 , wherein the distal opening of the cooling tube is swaged to form a cross section of reduced inner diameter. 
     
     
         7 . The side-firing energy emission probe of  claim 6 , wherein the cross section of the reduced inner diameter is between 0.002 and 0.006 inches. 
     
     
         8 . The side-firing energy emission probe of  claim 2 , further comprising a temperature measurement element disposed within the housing, wherein the temperature measurement element is configured to:
 measure a temperature within the cooling chamber region; and   provide the temperature to an external flow rate controller for controlling a flow of the cooling gas.   
     
     
         9 . The side-firing energy emission probe of  claim 8 , wherein the temperature measurement element comprises a thermocouple. 
     
     
         10 . The side-firing energy emission probe of  claim 2 , wherein the housing comprises:
 a cannula portion; and   a transparent capsule portion, wherein the transparent capsule portion is fixed to a distal end of the cannula portion.   
     
     
         11 . The side-firing energy emission probe of  claim 2 , wherein regions of the unsheathed portion surrounding the at least one facet include cladding, and the at least one facet is defined by removing cladding from faceted regions. 
     
     
         12 . The side-firing energy emission probe of  claim 2 , wherein the at least one facet comprises an etched surface of the unsheathed portion. 
     
     
         13 . A system for treatment of a tissue comprising:
 a side-firing energy emission probe comprising
 a housing, 
 a cooling tube configured for delivery of a coolant gas to a gas chamber region of a distal end of the side-firing energy emission probe, and 
   an optical fiber having a distal end comprising at least one facet, wherein the at least one facet is configured to emit energy within the gas chamber region and through a transparent surface region of the housing at an angle to a longitudinal axis of the optical fiber;   an energy source to generate laser energy for the side-firing energy emission probe;   a gas coolant source; and   a workstation comprising processing circuitry and a non-transitory computer readable medium having instructions stored thereon, wherein the instructions, when executed by the processing circuitry, cause the processing circuitry to effect treatment to a target area of the tissue, wherein effecting treatment comprises:
 activating the energy source, and 
 activating a gas flow of the gas coolant source. 
   
     
     
         14 . The system of  claim 13 , wherein effecting treatment to the target area of the tissue further comprises:
 receiving an indication of temperature regarding at least one of i) a tissue temperature of tissue abutting the distal end of the side-firing energy emission probe, and ii) a gas chamber temperature of the gas chamber region of the side-firing energy emission probe; and   responsive to the indication of temperature, adjusting at least one of a flow rate and a pressure of the gas flow.   
     
     
         15 . The system of  claim 14 , adjusting the at least one of the flow rate and the pressure of the gas flow comprises maintaining the gas chamber temperature between −20° C. and 20° C. 
     
     
         16 . The system of  claim 14 , wherein adjusting the pressure of the gas flow comprises adjusting the pressure to a value between 700 and 850 psi. 
     
     
         17 . The system of  claim 14 , wherein adjusting the flow rate of the gas flow comprises adjusting the flow rate to a value between 1 and 15 litres per minute. 
     
     
         18 . The system of  claim 13 , wherein the at least one facet comprises two or more facets longitudinally displaced along the optical fiber. 
     
     
         19 . The system of  claim 13 , wherein the at least one facet comprises two or more facets in a sawtooth pattern. 
     
     
         20 . A method for tissue treatment using a side-firing energy emission probe, comprising:
 identifying a target that comprises tissue for treatment;   percutaneously inserting a side-firing energy emission probe comprising
 a housing, 
 a cooling tube configured for delivery of a coolant gas to an gas chamber region of a distal end of the side-firing energy emission probe, and 
 an optical fiber having a distal end comprising at least one facet, wherein the at least one facet is configured to emit energy within the gas chamber region and through a transparent surface region of the housing at an angle to a longitudinal axis of the optical fiber; 
   positioning the side-firing energy emission probe such that the target is positioned at the angle to the longitudinal axis of the optical fiber;   emitting energy from the optical fiber sufficient to treat the target by directing laser energy through the optical fiber; and   during energy emission, cooling a distal end of the side-firing energy emission probe to prevent overheating tissue abutting an exterior surface of the side-firing energy emission probe by directing cooling gas to the gas chamber in the distal end of the side-firing energy emission probe through the coolant tube.   
     
     
         21 . The method of  claim 20 , wherein cooling the distal end of the side-firing emission probe comprises surrounding the at least one facet with the cooling gas such that no condensate forms on the at least one faceted surface.