Program Information
Clinical Feasibility of Energy-Resolved Dose Proton Radiography with X-Ray Flat Panel
E Bentefour1*, C Chirvase2 , F Vander Stappen3 , R Barlow4 , B Teo5 , (1) Ion Beam Applications, US, PA, (2) ,,,(3) Ion Beam Applications (IBA), Louvain-la-neuve, Brabant Wallon, (4) University of Huddersfield, Huddersfield, Huddersfield, (5) UNIVERSITY OF PENNSYLVANIA, Philadelphia, Pennsylvania
Presentations
SU-K-702-14 (Sunday, July 30, 2017) 4:00 PM - 6:00 PM Room: 702
Purpose: The purpose is to demonstrate that one can use x-ray flat panel from proton therapy PBS treatment rooms to perform Proton Energy Resolved Dose imaging (PERDi) at acceptable imaging dose and with sufficient accuracy.
Methods: PERDi performance was investigated using a proton friendly 2D detector (Lynx, 900 cm² active area and 0.5mm resolution). A solid water phantom and a tissue surrogate CIRS phantom were imaged to determine the accuracies of WEPL and RSP for several imaging fields. Imaging fields are made of a number of PBS layers designed to deliver uniform dose to 900cm2 at isocenter. The beam spot weight is 2.5cGy/cm2. The imaging field that produces sufficient WEPL and RSP accuracies at the lowest dose is selected for use with the X-ray flat panel (PaxScan 4030E, 127μm resolution) of the PBS proton treatment room. The efficiency of the x-ray flat panel was investigated to determine the appropriate spot weight for PERDi with the flat panel. Several phantoms were imaged and their WEPL and RSP’s accuracies were assessed.
Results: (2mm, 2%) accuracies of WEPL and RSP is achieved using the Lynx detector and an imaging field of 10 PBS layers (equivalent of 10cGy/cm2 total dose). The efficiency study of the flat panel showed that 100µGy/cm2 is an optimal spot weight which is 100 times less than the imaging dose needed with the Lynx. The measured proton radiographs with the flat panel were of excellent quality. The 2mm, 2% accuracies of WEPL and RSP were achieved at total dose of 1mGy/cm2. The imaging of a head phantom, in the same condition, produced WEPL radiograph of similar quality.
Conclusion: PBS treatment room x-ray flat panel is used with PERDi to produce useful proton radiographs. It demonstrate that PERDi is a reliable and inexpensive path to enable clinical proton imaging
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