RBE estimation of proton radiation fields using a {Delta}E-E telescope

Journal Article · Thu Oct 15 00:00:00 EDT 2009 · Medical Physics

DOI:https://doi.org/10.1118/1.3215927· OSTI ID:22102105

Wroe, Andrew; Schulte, Reinhard; Fazzi, Alberto; Pola, Andrea; Agosteo, Stefano; Rosenfeld, Anatoly ^[1]

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1. Department of Radiation Medicine, Loma Linda University Medical Center, California 92354 (United States) and Centre for Medical Radiation Physics, University of Wollongong, 2500 (Australia)

A new monolithic silicon {Delta}E-E telescope was evaluated in unmodulated and modulated 100 MeV proton beams used for hadron therapy. Compared to a classical microdosimetry detector, which provides one-dimensional information on lineal energy of charged particles, this detector system provides two-dimensional information on lineal energy and particle energy based on energy depositions, collected in coincidence, within the {Delta}E and E stages of the detector. The authors investigated the possibility to use the information obtained with the {Delta}E-E telescope to determine the relative biological effectiveness (RBE) at defined locations within the proton Bragg peak and spread-out Bragg peak (SOBP). An RBE matrix based on the established in vitro V79 cell survival data was developed to link the output of the device directly to RBE({alpha}), the RBE in the low-dose limit, at various depths in a homogeneous polystyrene phantom. In the SOBP of a 100 MeV proton beam, the RBE({alpha}) increased from 4.04 proximal to the SOBP to a maximum value of 5.4 at the distal edge. The {Delta}E-E telescope, with its high spatial resolution, has potential applications to biologically weighted hadron treatment planning as it provides a compact and portable means for estimating the RBE in rapidly changing hadron radiation fields within phantoms.

• OSTI ID: 22102105
• Journal Information: Medical Physics, Vol. 36, Issue 10; Other Information: (c) 2009 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
62 RADIOLOGY AND NUCLEAR MEDICINE
BRAGG CURVE
CHARGED PARTICLES
DOSE LIMITS
IN VITRO
MEV RANGE 10-100
MICRODOSIMETRY
ONE-DIMENSIONAL CALCULATIONS
PLANNING
PROTON BEAMS
PROTONS
RADIOTHERAPY
RBE
SEMICONDUCTOR DETECTORS
SPATIAL RESOLUTION
TELESCOPES
TWO-DIMENSIONAL CALCULATIONS