Peripheral Brachytherapy of Protruding Conformable Organs

Abstract

A system for and method of applying non-invasive brachytherapy to a targeted volume within a protruding organ of a patient, employs an applicator constructed so as to be positioned relative to the organ so that an enhanced dose of divergent radiation is deliverable from at least two locations at or very near the periphery of the organ transcutaneously to the targeted volume of the protruding organ from at least two directions so that a higher dose is delivered to the targeted volume than to tissue surrounding the targeted volume. The treatment planning, and image guidance techniques are also described.

1 . A method of non-invasively delivering brachytherapy to a designated volume within a protruding organ, comprising:
 a. Identifying a designated volume within the organ in need of radiation treatment, and determining locations at or near the periphery of the organ from which an enhanced dose of divergent radiation can be transcutaneously delivered to the designated volume of the protruding organ so that a higher dose is delivered to the designated volume than to tissue surrounding the designated volume;   b. Employing image guidance to locate the designated volume;   c. Securing a non-invasive applicator to the organ so that the applicator can receive and fixedly position at least one radiation source relative to the designated volume; and   d. Exposing for a predetermined amount of time the designated volume at each of the determined locations at or near the periphery of the organ so that a therapeutic dose is delivered to the targeted volume and a sub-therapeutic dose is delivered to the targeted volume and a sub-therapeutic dose is delivered to tissue surrounding the designated volume.   
     
     
         2 . A system for non-invasively delivering brachytherapy to a designated volume within a protruding organ, comprising:
 a. an imaging system constructed and arranged so as to (a) Identify a designated volume within the organ in need of radiation treatment, (b) aid in the determination of locations at or near the periphery of the organ from which an enhanced dose of divergent radiation can be transcutaneously delivered to the designated volume of the protruding organ so that a higher dose is delivered to the designated volume than to tissue surrounding the designated volume; and (c) assist in the employment of image guidance to locate the designated volume;   b. a non-invasive applicator shaped so that the applicator can be fixed relative to the organ, the applicator being constructed and arranged so that the applicator can receive and fixedly position at least one radiation source relative to the designated volume; expose for a predetermined amount of time the designated volume at each of the determined locations at or near the periphery of the organ so that a therapeutic dose is delivered to the targeted volume and a sub-therapeutic dose is delivered to the targeted volume and a sub-therapeutic dose is delivered to tissue surrounding the designated volume.   
     
     
         3 . A method of applying brachytherapy to a protruding organ, comprising:
 placing a non-invasive applicator on the organ, the applicator constructed and arranged so as to receive at least one radiation source and expose a designated volume within the organ from at least two dwell positions;   controlling the dwell position and the dwell time of the radiation source placed via the applicator at a close distance to the periphery of the organ such that the diverging exposure field from each dwell position is superpositioned on the diverging exposure field from other dwell positions to deliver a therapeutic dose to a large portion or substantially the entire volume of the said organ.   
     
     
         4 . A system for applying brachytherapy to a protruding organ, comprising:
 a non-invasive applicator configured to contact the organ during treatment, the applicator constructed and arranged so as to receive at least one radiation source and expose transcutaneously a designated portion of the organ from at least two dwell positions; and controlling the dwell time of the radiation source at each of the dwell positions placed via the applicator at or near the periphery of the organ such that the diverging exposure field from each dwell position is superpositioned on the diverging exposure field from other dwell positions to deliver a therapeutic dose to a targeted volume within the organ.   
     
     
         5 . The method of applying brachytherapy to a designated volume within a protruding organ:
 using image guidance to locate the designated volume;   placing on the organ a non-invasive applicator with at least one radiation source so that the designated volume can be exposed transcutaneously for a predetermined dwell time for each of at least two dwell positions at or near the periphery of the organ; and   controlling the dwell position and the dwell time of the radiation exposure at each of the dwell positions such that the diverging exposure field from each dwell position is superpositioned on the diverging exposure field from other dwell positions to deliver a therapeutic dose to the designated volume and a sub-therapeutic dose to other tissue adjacent the designated volume.   
     
     
         6 . The system for applying brachytherapy to a designated volume within a protruding organ:
 an imaging system for defining the designated volume;   a non-invasive applicator with at least one radiation source constructed to be placed on the organ so that the designated volume can be exposed transcutaneously for a predetermined dwell time for each of at least two dwell positions at or near the periphery of the organ; and control the dwell position and the dwell time of the radiation exposure at each of the dwell positions such that the diverging exposure field from each dwell position is superpositioned on the diverging exposure field from other dwell positions to deliver a therapeutic dose to the designated volume and a sub-therapeutic dose to other tissue adjacent the designated volume.   
     
     
         7 . A method of applying radiotherapy to a protruding organ, comprising:
 A. Compressing the protruding organ between two plates so as to define the initial treatment plane;   B. Imaging the protruding organ in the initial treatment plane while it is immobilized to identify the designated volume of tissue in need of radiotherapy;   C. Delivering radiotherapy to the designated volume while the protruding organ is immobilized from a direction within an angle of 30 degrees from normal to the initial treatment plane;   D. Removing the compression plates and rotating the compression plates to a new orientation which is within 60 to 120 degrees of the initial treatment plane, and re-applying compression to immobilize the said protruding organ at the new orientation;   E. Identifying the designated volume by imaging, or other means, within the protruding organ from the new orientation;   F. Delivering radiotherapy to the designated volume while the protruding organ is immobilized in the new orientation from a direction substantially normal to the compression plates;   G. Repeating steps D to F, as needed until a therapeutic dose is delivered to the designated volume within the protruding organ.   
     
     
         8 . The method of  claim 7 , where the protruding organ is the breast. 
     
     
         9 . The method of  claim 8 , wherein the breast has been subjected to a lumpectomy procedure and wherein the designated volume is the lumpectomy cavity margin. 
     
     
         10 . The method of  claim 7 , comprising the means of compression, imaging and delivering radiation therapy are performed with a single apparatus. 
     
     
         11 . An apparatus for applying radiotherapy to a protruding organ, comprising:
 A. a pair of plates constructed and arranged so as to compress the protruding organ and define an initial treatment plane, wherein the compression plates are adapted to rotate to at least a second orientation, and re-applying compression to immobilize the said protruding organ at the new orientation;   B. an imaging device constructed and arranged so as to image the protruding organ in the initial treatment plane while the organ is immobilized and so as to identify the designated volume of tissue in need of radiotherapy, and identify the designated volume in the second orientation;   C. a radiation delivery system constructed and arranged so as to deliver radiotherapy to the designated volume while the protruding organ is immobilized from a direction within an angle of 30 degrees from normal to the initial treatment plane.   
     
     
         12 . The system according to  claim 11 , wherein the second orientation is within 60 to 120 degrees of the initial treatment plane. 
     
     
         13 . The system according to  claim 11 , where the protruding organ is the breast. 
     
     
         14 . The system according to  claim 13 , wherein the breast has been subjected to a lumpectomy procedure and wherein the designated volume is the lumpectomy cavity margin. 
     
     
         15 . A system for applying non-invasive brachytherapy to a targeted volume within a conformable protruding organ of a patient, comprising:
 an applicator constructed so as to be positioned relative to the organ so that an enhanced dose of divergent radiation is deliverable from at least two locations at or very near the periphery of the conformable protruding organ transcutaneously to the targeted volume of the conformable protruding organ from at least two directions so that a higher dose is delivered to the targeted volume than to tissue surrounding the targeted volume;   treatment planning program used to guide the use of the applicator; and   an image guidance device constructed and arranged so as image the targeted volume   wherein the treatment planning program and image guidance device is sued to determine the optimum treatment plan.   
     
     
         16 . A system according to  claim 15 , wherein the treatment planning program includes parameter determination subprogram configured and arranged so as to determine radiation exposure parameters including isodose center, dose volume and dose uniformity as a function of the designated dose and dose distribution with the size and shape of the protruding organ and the location and extent of the targeted volume, as identified from the image guidance device. 
     
     
         17 . A system according to  claim 16 , wherein the treatment planning program includes a subprogram configured and arranged so as to determine the position, intensity, size shape, and energy of one or more sources for providing the enhanced dose as a function of the targeted volume, which in turn is determined by the size and shape of the organ, or the size and shape of the designated volume identified from the image guidance device. 
     
     
         18 . A system according to  claim 17 , wherein the treatment planning program includes a subprogram configured and arranged so as to determine the dwell position, swell patter, and dwell time, of one or more sources for providing the enhanced dose coincides with the targeted volume. 
     
     
         19 . A system according to  claim 15 , further including image markers arranged to align the position of the applicator to coordinates of the organ to coincide radiation treatment with the targeted volume. 
     
     
         20 . A method of applying non-invasive brachytherapy to a targeted volume within a conformable protruding organ of a patient, comprising:
 positioning an applicator positioned relative to the organ so that an enhanced dose of divergent radiation is deliverable from at least two locations at or very near the periphery of the conformable protruding organ transcutaneously to the targeted volume of the conformable protruding organ from at least two directions so that a higher dose is delivered to the targeted volume than to tissue surrounding the targeted volume;   using a treatment planning program to guide the use of the applicator;   using an image guidance device to image the targeted volume so as to determine the optimum treatment plan.   
     
     
         21 . A method according to  claim 20 , wherein using the treatment planning program includes determining radiation exposure parameters including isodose center, dose volume and dose uniformity as a function of the designated dose and dose distribution with the size and shape of the protruding organ and the location and extent of the targeted volume, as identified from the image guidance device. 
     
     
         22 . A method according to  claim 20 , wherein using the treatment planning program includes
 determining by the size and shape of the organ, or the size and shape of the designated volume identified from the image guidance device; and   determining the position, intensity, size shape, and energy of one or more sources for providing the enhanced dose as a function of the targeted volume.   
     
     
         23 . A method according to  claim 20 , wherein using the treatment planning program includes determining the dwell position, swell patter, and dwell time, of one or more sources for providing the enhanced dose as it coincides with the targeted volume. 
     
     
         24 . A method according to  claim 20 , further including using image markers arranged to align the position of the applicator to coordinates of the organ to coincide radiation treatment with the targeted volume.