scholarly journals Optimum size of a calibration phantom for x-ray CT to convert the Hounsfield units to stopping power ratios in charged particle therapy treatment planning

2017 ◽  
Vol 59 (2) ◽  
pp. 216-224 ◽  
Author(s):  
T Inaniwa ◽  
H Tashima ◽  
N Kanematsu
Keyword(s):  
Charged Particle ◽  
Treatment Planning ◽  
Particle Therapy ◽  
Stopping Power ◽  
Optimum Size ◽  
Hounsfield Units ◽  
X Ray ◽  
Calibration Phantom ◽  
Charged Particle Therapy ◽  
Therapy Treatment

scholarly journals Stopping-power ratio of mouthpiece materials for charged-particle therapy in head and neck cancer

2020 ◽  
Author(s):  
Hiroaki Ikawa ◽  
Taku Inaniwa ◽  
Masashi Koto ◽  
Tapesh Bhattacharyya ◽  
Takashi Kaneko ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Charged Particle ◽  
Head And Neck ◽  
Treatment Planning ◽  
Neck Cancer ◽  
Particle Therapy ◽  
Stopping Power ◽  
Ct Number ◽  
Conversion Table ◽  
Charged Particle Therapy

Abstract Background: In charged-particle therapy treatment planning, CT numbers of a patient’s body are converted into stopping power ratios (SPRs) using a CT-number-to-SPR conversion table constructed for standard human tissues. Since artificial devices used in treatments of head and neck cancer, such as mouthpieces, do not fit into the CT-number-to-SPR conversion table, they may deteriorate treatment accuracy. In this study, the SPRs of five mouthpiece materials were measured, and the error in predicted SPRs based on the conversion table was investigated.Methods: SPRs of five mouthpiece materials were predicted from their CT numbers using a calibrated conversion table. Independently, the SPRs of the materials were measured by the Bragg-peak shift of a carbon-ion beam passing through the materials. The errors in SPR of the materials were determined as the difference between the predicted and measured SPRs.Results: The SPRs (error) of the ethylene-vinyl acetate copolymers (EVAs), Nipoflex 710TM and BioplastTM, were 0.997 (0.023) and 0.982 (0.007), respectively. The SPRs (error) of the vinyl silicon impression material (Exafine putty typeTM), the light curable resin (Clear Photoreactive Resin for Formlabs 3D printersTM), and the bis-acrylic resin (TempsmartTM) were 1.517 (0.134), 1.161 (0.068), and 1.26 (0.101), respectively. Conclusions: The EVA BioplastTM had the minimum SPR error among the five tested materials, indicating the highest human-tissue equivalency. If other artificial materials such as Exafine putty typeTM are used as mouthpieces, it is recommended that their SPRs be overwritten by the correct values in treatment planning processes.

Accelerators for charged particle therapy

2015 ◽  
Vol 30 (17) ◽  
pp. 1540020 ◽  
Author(s):  
Jacob Flanz
Keyword(s):  
Charged Particle ◽  
Energetic Particles ◽  
Particle Therapy ◽  
Medical Applications ◽  
X Rays ◽  
X Ray ◽  
Medicine Development ◽  
Charged Particle Therapy

History has shown that energetic particles can be useful for medical applications. From the time, in 1895 when Roentgen discovered X-rays, and in 1913 when Coolidge developed the vacuum X-ray tube, energetic particles have been an important tool for medicine. Development of the appropriate tool for effective and safe radiotherapy requires an in-depth understanding of the application and constraints. Various solutions are possible and choices must be analyzed on the basis of the suitability for meeting the requirements. Some of the requirements of charged particle therapy are summarized and various accelerator options are described and discussed.

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