Prog Med Phys.  2020 Sep;31(S1):S55.

Monitoring Tumor Size Using PET with a Collimator during Boron Neutron Capture Therapy: Simulation Study

• Yang HJ
• Yoon DK
• Suh TS

Abstract

Purpose
The purpose of this study was to demonstrate the feasibility of sensing changes in a tumor during boron neutron capture therapy (BNCT) using a Monte Carlo simulation tool.
Methods
In the simulation, an epi-thermal neutron source and a water phantom including boron uptake regions (BURs) were simulated. Moreover, this simulation also included a detector for positron emission tomography (PET) scanning and an adaptively-designed collimator (ADC) added to PET’s gantry. The projection acquisition was obtained before and during treatment. The modified OSEM reconstruction method was used to reconstruct all images and then the image profiles were collected to analyze quantitatively.
Results
Single prompt gamma rays were collected through the ADC into a neutron beam. Then, single prompt gamma ray-based tomography images were acquired of variably sized tumors by a four-step process. Both the signal-to-noise ratio (SNR) and tumor size were analyzed from each step image. From this analysis, we identified a decreasing trend of both the SNR and signal intensity as the tumor size decreased, which was confirmed in all images.
Conclusions
In conclusion, we confirmed the feasibility of sensing changes in a tumor during BNCT using PET and an ADC through Monte Carlo simulation.

Keyword

Boron neutron capture therapy; PET; Adaptively-designed collimator