A novel flat-panel detector for advanced on-board radiation therapy imaging

Project Summary
Despite recent technological advances, on-treatment imaging for radiotherapy procedures is still a significant
challenge for tens of thousands of patients. On-board MRI or kV x-ray systems are either prohibitively
expensive, provide incomplete information, or are incompatible with implanted metal devices. According to the
American College of Radiology, megavoltage (MV) volumetric imaging has a clear advantage in terms of metal
artifact reduction, direct dose calculation and real-time adaptive radiotherapy, but is challenged by low contrast
and high imaging doses. We have demonstrated that this limitation can be overcome by a novel multi-layer
imager to provide high-contrast, low-dose on-treatment MV imaging. This new technology will remove metal
artifacts while retaining soft-tissue contrast and enable real-time adaptive radiotherapy. We have invented and
validated a Monte Carlo-based tool that enables accurate image simulation in a fraction of the time required for
conventional Monte Carlo simulation – enabling efficient imager optimization to be performed. Our preliminary
data with a novel low-cost scintillator and efficient layering combinations has already demonstrated low-
dose/high-quality MV-CBCT, rivaling conventional kV-CBCT, with added benefits of artifact reduction and
Hounsfield unit accuracy. The Specific Aims of the current proposal will leverage our combined experience and
previous results to produce an optimized imager suitable for widespread clinical use.
PHS 398/2590 (Rev. 06/09) Page Continuation Format Page

Grant Number: 5R01CA188446-10
NIH Institute/Center: NIH
Principal Investigator: Ross Berbeco