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S String1*, W Muhammad2, C Shang3, (1) FAU, Boca Raton, FL, (2) Florida Atlantic University, Boca Raton, FL, (3) South Florida Proton Therapy Institute, Delray Beach, FL


(Sunday, 7/12/2020)   [Eastern Time (GMT-4)]

Room: AAPM ePoster Library

Proton therapy is a novel technique to treat cancer patients due to its unique biophysical properties. However, a small error in dose calculation may lead towards a huge variation in planed doses to the target and associated organs-at risk (OARs). The aim of this project is to create a simulation model of Varian ProBeam Compact Single-Room Proton Therapy System using the GEANT4 Monte Carlo (MC) simulation tool kit. The model will be used to simulate the dose distributions through depth and lateral dose distribution with a given range shifter thickness and position.

The simulation was started from a model of the passive beam line in CATANA, part of the Italian National Laboratory of the South (LNS), from the hadron therapy GEANT4 application. The parameters were then modified to the specifications of the Varian ProBeam Compact Single-Room Proton Therapy System. The beam line consists of the gantry, with its various components (collimators, range shifters, etc.), pointing at a water phantom. Experimental dose data of the ProBeam acquired in a liquid water phantom with a monitor chamber at the South Florida Proton Therapy Institute (SFPTI) is used to validate the simulation model. The data from both the simulation and SFPTI are normalized.

Simulating one million particles for 70 MeV and comparing to the data from SFPTI, we have a correlation coefficient, or “r”, of 0.9885. Which gives us an r square value of 0.9772.

The MC simulation model will be a tool for clinics to study dose depth curves, lateral dose distributions and dose uncertainties while treating the patients with the Varian ProBeam Compact Single-Room Proton Therapy System.


Not Applicable / None Entered.


Not Applicable / None Entered.

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