Deformable Gel Based Phantoms to Improve Accuracy of Dose Calculations in Thoracic Treatment Planning using 3D Magnetic Resonance Relaxometry


SDSU Co-Leader

Usha Sinha, Ph.D.  

UCSD Co-Leader

Todd Pawlicki, Ph.D.



Lung cancer accounts for 28% of all cancer deaths in the US.  Further, differences in lung cancer survival between racial groups related to healthcare access and quality have been identified.  The treatment of lung cancer is complicated by motion and changes in shape (deformations) of the lungs and the cancer as the patient breathes.  Considerable progress has been made in the development of new software and imaging at multiple points of the respiratory cycle to address the motion and deformation in order to deliver the radiation dose accurately to the cancer while minimizing dose to the surrounding normal tissue.  However, these techniques are new and there is a need for accurate verification of these methods at each site where the technique is implemented.  We propose a 4D dose monitoring method based on gel dosimeters and magnetic resonance imaging to map the changes in the gel with irradiation.  Successful implementation will enable validation, optimization, and customization of complex lung cancer radiation therapy, which can then be translated readily to community clinics.  The ultimate aim is to provide access to state-of-art radiation therapy treatment for lung cancer to the minority populations served by these clinics.

Project Period: 6/1/2012 – 8/31/2013

Selected Outcomes


R Hira, U Sinha, S Sinha, T Pawlicki. Evaluation of a stepped TE segmented EPI sequence for Relaxometry Based MR Gel Dosimetry at 1.5T and 3T. 20th Annual ISMRM Meeting – Melbourne, Australia, May 2012.