In vivo verification of particle therapy: how Compton camera configurations affect 3D image quality

9th International Conference on 3D Radiation Dosimetry

Mackin, D.^1 ; Draeger, E.^2 ; Peterson, S.^3 ; Polf, J.^2 ; Beddar, S.^1

Department of Radiation Physics, University of Texas, MD Anderson Cancer Center, Unit 94, 1515 Holcombe Boulevard, Houston

TX

77030, United States^1

Department of Radiation Oncology, University of Maryland, School of Medicine, Baltimore

MD

21201, United States^2

Department of Physics, University of Cape Town, Rondebosch

7700, South Africa^3

关键词: Compton Camera;    Dose distributions;    Healthy tissues;    Particle therapy;    Patient anatomy;    Patient setup errors;    Range uncertainty;    Stopping power;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/847/1/012045/pdf
DOI  :  10.1088/1742-6596/847/1/012045

来源: IOP

【 摘 要 】

The steep dose gradients enabled by the Bragg peaks of particle therapy beams are a double edged sword. They enable highly conformal dose distributions, but even small deviations from the planned beam range can cause overdosing of healthy tissue or under-dosing of the tumour. To reduce this risk, particle therapy treatment plans include margins large enough to account for all the sources of range uncertainty, which include patient setup errors, patient anatomy changes, and CT number to stopping power ratios. Any system that could verify the beam range in vivo, would allow reduced margins and more conformal dose distributions. Toward our goal developing such a system based on Compton camera (CC) imaging, we studied how three configurations (single camera, parallel opposed, and orthogonal) affect the quality of the 3D images. We found that single CC and parallel opposed configurations produced superior images in 2D. The increase in parallax produced by an orthogonal CC configuration was shown to be beneficial in producing artefact free 3D images.