SU-D-BRE-04: Evaluating the Dose Accuracy of a 2D Ion Chamber Array in High Dose Rate Pencil Beam Scanning Proton Beam

2014 ◽  
Vol 41 (6Part3) ◽  
pp. 112-112
Author(s):  
L Perles ◽  
A Mascia ◽  
F Piskulich ◽  
R Lepage ◽  
Y Zhang ◽  
...  
Keyword(s):  
Dose Rate ◽  
Proton Beam ◽  
High Dose Rate ◽  
High Dose ◽  
Pencil Beam ◽  
Beam Scanning ◽  
Ion Chamber ◽  
Pencil Beam Scanning ◽  
Dose Accuracy

scholarly journals FLASH Proton Pencil Beam Scanning Irradiation Minimizes Radiation-Induced Leg Contracture and Skin Toxicity in Mice

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1012
Author(s):  
Shannon Cunningham ◽  
Shelby McCauley ◽  
Kanimozhi Vairamani ◽  
Joseph Speth ◽  
Swati Girdhani ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Proton Beam ◽  
Skin Toxicity ◽  
Tumor Control ◽  
High Dose ◽  
Pencil Beam ◽  
Beam Scanning ◽  
Dose Rates ◽  
Pencil Beam Scanning ◽  
Tgf Β1

Ultra-high dose rate radiation has been reported to produce a more favorable toxicity and tumor control profile compared to conventional dose rates that are used for patient treatment. So far, the so-called FLASH effect has been validated for electron, photon and scattered proton beam, but not yet for proton pencil beam scanning (PBS). Because PBS is the state-of-the-art delivery modality for proton therapy and constitutes a wide and growing installation base, we determined the benefit of FLASH PBS on skin and soft tissue toxicity. Using a pencil beam scanning nozzle and the plateau region of a 250 MeV proton beam, a uniform physical dose of 35 Gy (toxicity study) or 15 Gy (tumor control study) was delivered to the right hind leg of mice at various dose rates: Sham, Conventional (Conv, 1 Gy/s), Flash60 (57 Gy/s) and Flash115 (115 Gy/s). Acute radiation effects were quantified by measurements of plasma and skin levels of TGF-β1 and skin toxicity scoring. Delayed irradiation response was defined by hind leg contracture as a surrogate of irradiation-induced skin and soft tissue toxicity and by plasma levels of 13 different cytokines (CXCL1, CXCL10, Eotaxin, IL1-beta, IL-6, MCP-1, Mip1alpha, TNF-alpha, TNF-beta, VEGF, G-CSF, GM-CSF and TGF- β1). Plasma and skin levels of TGF-β1, skin toxicity and leg contracture were all significantly decreased in FLASH compared to Conv groups of mice. FLASH and Conv PBS had similar efficacy with regards to growth control of MOC1 and MOC2 head and neck cancer cells transplanted into syngeneic, immunocompetent mice. These results demonstrate consistent delivery of FLASH PBS radiation from 1 to 115 Gy/s in a clinical gantry. Radiation response following delivery of 35 Gy indicates potential benefits of FLASH versus conventional PBS that are related to skin and soft tissue toxicity.

scholarly journals Silicon 3D Microdosimeters for Advanced Quality Assurance in Particle Therapy

2021 ◽  
Vol 12 (1) ◽  
pp. 328
Author(s):  
Linh T. Tran ◽  
David Bolst ◽  
Benjamin James ◽  
Vladimir Pan ◽  
James Vohradsky ◽  
...  
Keyword(s):  
High Dose Rate ◽  
Low Noise ◽  
Silicon On Insulator ◽  
Particle Therapy ◽  
High Dose ◽  
Pencil Beam ◽  
High Definition ◽  
Beam Scanning ◽  
Radiation Physics ◽  
Pencil Beam Scanning

The Centre for Medical Radiation Physics introduced the concept of Silicon On Insulator (SOI) microdosimeters with 3-Dimensional (3D) cylindrical sensitive volumes (SVs) mimicking the dimensions of cells in an array. Several designs of high-definition 3D SVs fabricated using 3D MEMS technology were implemented. 3D SVs were fabricated in different sizes and configurations with diameters between 18 and 30 µm, thicknesses of 2–50 µm and at a pitch of 50 µm in matrices with volumes of 20 × 20 and 50 × 50. SVs were segmented into sub-arrays to reduce capacitance and avoid pile up in high-dose rate pencil beam scanning applications. Detailed TCAD simulations and charge collection studies in individual SVs have been performed. The microdosimetry probe (MicroPlus) is composed of the silicon microdosimeter and low-noise front–end readout electronics housed in a PMMA waterproof sheath that allows measurements of lineal energies as low as 0.4 keV/µm in water or PMMA. Microdosimetric quantities measured with SOI microdosimeters and the MicroPlus probe were used to evaluate the relative biological effectiveness (RBE) of heavy ions and protons delivered by pencil-beam scanning and passive scattering systems in different particle therapy centres. The 3D detectors and MicroPlus probe developed for microdosimetry have the potential to provide confidence in the delivery of RBE optimized particle therapy when introduced into routine clinical practice.

scholarly journals Commissioning of a clinical pencil beam scanning proton therapy unit for ultra‐high dose rates (FLASH)

2021 ◽  
Author(s):  
Konrad P. Nesteruk ◽  
Michele Togno ◽  
Martin Grossmann ◽  
Anthony J. Lomax ◽  
Damien C. Weber ◽  
...  
Keyword(s):  
Proton Therapy ◽  
High Dose ◽  
Pencil Beam ◽  
Beam Scanning ◽  
Dose Rates ◽  
Pencil Beam Scanning

scholarly journals Comparison of multi-institutional Varian ProBeam pencil beam scanning proton beam commissioning data

2017 ◽  
Vol 18 (3) ◽  
pp. 96-107 ◽  
Author(s):  
Ulrich W. Langner ◽  
John G. Eley ◽  
Lei Dong ◽  
Katja Langen
Keyword(s):  
Proton Beam ◽  
Pencil Beam ◽  
Beam Scanning ◽  
Pencil Beam Scanning ◽  
Beam Commissioning
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