Real-time, volumetric imaging of radiation dose delivery deep into the liver during cancer treatment

Authors: Wei Zhang, Ibrahim Oraiqat, Dale Litzenberg, Kai-Wei Chang, Scott Hadley, Noora Ba Sunbul, Martha M. Matuszak,  Christopher J. Tichacek, Eduardo G. Moros, Paul L. Carson, Kyle C. Cuneo, Xueding Wang, & Issam El Naqa


Ionizing radiation acoustic imaging (iRAI) allows online monitoring of radiation’s interactions with tissues during radiation therapy, providing real-time, adaptive feedback for cancer treatments. We describe an iRAI volumetric imaging system that enables mapping of the three-dimensional (3D) radiation dose distribution in a complex clinical radiotherapy treatment. The method relies on a two-dimensional matrix array transducer and a matching multi-channel preamplifier board. The feasibility of imaging temporal 3D dose accumulation was first validated in a tissue-mimicking phantom. Next, semiquantitative iRAI relative dose measurements were verified in vivo in a rabbit model. Finally, real-time visualization of the 3D radiation dose delivered to a patient with liver metastases was accomplished with a clinical linear accelerator. These studies demonstrate the potential of iRAI to monitor and quantify the 3D radiation dose deposition during treatment, potentially improving radiotherapy treatment efficacy using real-time adaptive treatment.