System for delivering conformal radiation therapy while simultaneously imaging soft tissue

Abstract

A device and a process for performing high temporal- and spatial-resolution MR imaging of the anatomy of a patient during intensity modulated radiation therapy (IMRT) to directly measure and control the highly conformal ionizing radiation dose delivered to the patient for the treatment of diseases caused by proliferative tissue disorders. This invention combines the technologies of open MRI, multileaf-collimator or compensating filter-based IMRT delivery, and cobalt teletherapy into a single co-registered and gantry mounted system.

1 . A radiation treatment system, comprising:
 an irradiating device configured to deliver ionizing radiation to a subject from one or more treatment beams selected from the group of radioisotope beams, proton beams and heavy ion beams;   a magnetic resonance imaging system operably engaged with the irradiating device, the magnetic resonance imaging system configured to acquire a sequence of 3D images of the subject fast enough to capture intra-fraction organ motions;   a controller in communication with the irradiating device and the magnetic resonance imaging system and configured to substantially simultaneously
 a) control the magnetic resonance imaging system to acquire the 3D images of the subject; and 
 b) control the irradiating device to deliver ionizing radiation to the subject and record delivered treatment beam fluences; and 
 c) determine an actual dose deposition in the subject from the 3D images of the subject and the delivered treatment beam fluences. 
   
     
     
         2 . The radiation treatment system according to  claim 1  wherein a magnetic resonance imaging system magnetic field is substantially orthogonal to the one or more treatment beams. 
     
     
         3 . The radiation treatment system of  claim 2  further comprising a multi-leaf collimator configured to rapidly adjust radiation delivery to account for intra-fraction organ motions. 
     
     
         4 . The radiation treatment system of  claim 3 , wherein the multi-leaf collimator comprises a fixed primary collimator, a secondary doubly divergent multileaf collimator, and a tertiary multi-leaf collimator configured to block interleaf leakage from the secondary multi-leaf collimator. 
     
     
         5 . The radiation treatment system of  claim 2 , wherein the controller is configured to employ deformable image registration in determining the actual dose deposition in the subject. 
     
     
         6 . The radiation treatment system of  claim 2  wherein the controller is configured to deliver the ionizing radiation to the subject through intensity modulated radiation therapy. 
     
     
         7 . The radiation treatment system of  claim 6  wherein the controller is configured to reoptimize the delivery of ionizing radiation to the subject based on the determined actual dose deposition. 
     
     
         8 . The radiation treatment system of  claim 6  wherein the controller is configured to deliver of ionizing radiation to the subject based on a treatment plan. 
     
     
         9 . The radiation treatment system of  claim 8  wherein the controller is configured to alter the treatment plan based on the actual dose deposition. 
     
     
         10 . The radiation treatment system of  claim 2  wherein the controller is configured to stop the delivery of ionizing radiation to the subject if the actual dose deposition evidences a dosimetric error. 
     
     
         11 . The radiation treatment system of  claim 2 , wherein the magnetic resonance imaging system is further configured to acquire magnetic resonance imaging data that identifies regions of tracer uptake substantially simultaneously to the delivery of ionizing radiation to the subject. 
     
     
         12 . The radiation treatment system of  claim 2 , wherein the magnetic resonance imaging system is further configured to acquire magnetic resonance imaging data that identifies regions of contrast enhancement substantially simultaneously to the delivery of ionizing radiation to the subject. 
     
     
         13 . The radiation treatment system of  claim 2 , wherein the magnetic resonance imaging system is further configured to acquire spectroscopic information substantially simultaneously to the delivery of ionizing radiation to the subject. 
     
     
         14 . The radiation treatment system of  claim 2 , wherein the magnetic resonance imaging system is further configured to acquire one or more types of information selected from the group of metabolic information and physiological information substantially simultaneously to the delivery of ionizing radiation to the subject. 
     
     
         15 . The radiation treatment system of  claim 2 , wherein the magnetic resonance imaging system is further configured to acquire one or more types of information selected from the group of magnetic resonance angiography data and lymphangiography data substantially simultaneously to the delivery of ionizing radiation to the subject. 
     
     
         16 . The radiation treatment system of  claim 2 , wherein the magnetic resonance imaging system is further configured to perform in vivo thermometry. 
     
     
         17 . The radiation treatment system of  claim 2 , wherein the system is further configured to perform ablative therapy under substantially simultaneous image guidance. 
     
     
         18 . A method of radiation treatment comprising:
 delivering ionizing radiation to a subject with an irradiating device including one or more treatment beams selected from the group of radioisotope beams, proton beams and heavy ion beams;   acquiring, with a magnetic resonance imaging system operably engaged with the irradiating device, a sequence of 3D images of the subject fast enough to capture intra-fraction organ motions;   controlling the magnetic resonance imaging system to acquire the 3D images of the subject and, substantially simultaneously, controlling the irradiating device to deliver ionizing radiation to the subject; and,   recording delivered treatment beam fluences; and   determining an actual dose deposition in the subject from the 3D images of the subject and the delivered treatment beam fluences.   
     
     
         19 . The method of radiation treatment of  claim 18  wherein the delivering of ionizing radiation is performed with the one or more treatment beams being substantially orthogonal to a magnetic resonance imaging system magnetic field. 
     
     
         20 . The method of radiation treatment of  claim 18  further comprising rapidly adjusting radiation delivery with a multi-leaf collimator to account for intra-fraction organ motions. 
     
     
         21 . The method of radiation treatment of  claim 18  wherein determining the actual dose deposition further comprises the use of deformable image registration. 
     
     
         22 . The method of radiation treatment of  claim 18  wherein delivering ionizing radiation further comprises intensity modulated radiation therapy. 
     
     
         23 . The method of radiation treatment of  claim 18  further comprising reoptimizing the delivery of ionizing radiation to the subject based on the determined actual dose deposition 
     
     
         24 . The method of radiation treatment of  claim 18  wherein the delivering of ionizing radiation to the subject is based on a treatment plan. 
     
     
         25 . The method of radiation treatment of  claim 24  further comprising altering the treatment plan based on the actual dose deposition. 
     
     
         26 . The method of radiation treatment of  claim 18  further comprising stopping the delivery of ionizing radiation to the subject if the actual dose deposition evidences a dosimetric error.