Journal ArticleDOI
Inactivation of human normal and tumour cells irradiated with low energy protons.
Mauro Belli,Daniela Bettega,P. Calzolari,F. Cera,Roberto Cherubini,M. Dalla Vecchia,Marco Durante,S. Favaretto,G. Gialanella,G. F. Grossi,Renato Marchesini,G. Moschini,A. Piazzola,Gian Luca Poli,Mariagabriella Pugliese,Orazio Sapora,Paola Scampoli,Giustina Simone,Eugenio Sorrentino,M. A. Tabocchini,L. Tallone,P. Tiveron +21 more
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TLDR
RBE for inactivation with high-LET protons increased with the cellular radioresistance to gamma-rays, and a similar trend has been found in studies reported in the literature with He, C, N ions with LET in the range 20-125 keV/microm on human tumour cell lines.Abstract:
Purpose : To analyse the cell inactivation frequencies induced by low energy protons in human cells with different sensitivity to photon radiation. Materials and methods : Four human cell lines with various sensitivities to photon irradiation were used: the SCC25 and SQ20B derived from human epithelium tumours of the tongue and larynx, respectively, and the normal lines M/10, derived from human mammary epithelium, and HF19 derived from a lung fibroblast. The cells were irradiated with γ-rays and proton beams with linear energy transfer (LET) from 7 to 33keV/ μ m. Clonogenic survival was assessed. Results : Survival curves are reported for each cell line following irradiation with γ-rays and with various proton LETs. The surviving fraction after 2 Gy of γ-rays was 0.72 for SQ20B cells, and 0.28–0.35 for the other cell lines. The maximum LET proton effectiveness was generally greater than that of γ-rays. In particular there was a marked increase in beam effectiveness with increasing LET for the most resista...read more
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Journal ArticleDOI
Relative biological effectiveness (RBE) values for proton beam therapy.
Harald Paganetti,Andrzej Niemierko,Marek Ancukiewicz,Leo E. Gerweck,Michael Goitein,Jay S. Loeffler,Herman D. Suit +6 more
TL;DR: There is too much uncertainty in the RBE value for any human tissue to propose RBE values specific for tissue, dose/fraction, proton energy, etc, and experimental in vivo and clinical data indicate that continued employment of a generic RBEvalue is reasonable.
Journal ArticleDOI
Relative biological effectiveness (RBE) values for proton beam therapy. Variations as a function of biological endpoint, dose, and linear energy transfer
TL;DR: This review can serve as a source for defining input parameters for applying or refining biophysical models and to identify endpoints where additional radiobiological data are needed in order to reduce the uncertainties in proton RBE values to clinically acceptable levels.
Journal ArticleDOI
A phenomenological relative biological effectiveness (RBE) model for proton therapy based on all published in vitro cell survival data.
TL;DR: A model to predict proton RBE based on dose, dose average LET (LETd) and the ratio of the linear-quadratic model parameters for the reference radiation (α/β)x, as the tissue specific parameter is developed, based on the linear quadratic model and was derived from a nonlinear regression fit to 287 experimental data points.
Journal ArticleDOI
Systematic analysis of RBE and related quantities using a database of cell survival experiments with ion beam irradiation
TL;DR: The RBE values derived from the survival curves support the known dependence of RBE on LET, on particle species and dose, and resemble overall RBE uncertainties, which is of relevance for treatment planning.
Journal ArticleDOI
A model for the relative biological effectiveness of protons: the tissue specific parameter α/β of photons is a predictor for the sensitivity to LET changes.
TL;DR: By accounting for the α/β ratio of photons, clearer trends between RBE and LET of protons were found, and the results suggest that late responding tissues are more sensitive to LET changes than early responding tissues and most tumors.
References
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Journal ArticleDOI
Comments on ICRU Report No. 49: Stopping Powers and Ranges for Protons and Alpha Particles
TL;DR: The International Commission on Radiation Units and Measurements (ICRU) published report No. 49, Stopping Powers and Ranges for Protons and Alpha Particles, in 1993.
Journal ArticleDOI
The radioresponsiveness of human tumours and the initial slope ofthe cell survival curve
TL;DR: The surviving fraction at 2 Gy is shown to give good discrimination between resistant and sensitive tumour types and the relationship between the initial slope of the cell survival curve and clinical radioresponsiveness is demonstrated.
Journal ArticleDOI
Instrumentation for Treatment of Cancer Using Proton and Light-Ion Beams
TL;DR: This article reviews the beam modifying devices and associated dosimetric equipment developed specifically for controlling and monitoring the clinical beams.
Journal ArticleDOI
Induction of transformation and continuous cell lines from normal human mammary epithelial cells after exposure to benzo[a]pyrene.
TL;DR: Analysis of the multiple steps occurring in the El cultures, as well as in the emergence of the continuous cell lines, could potentially elucidate the processes occurring during human epithelial cell carcinogenesis and escape from senescence.
Induction of transformation and continuous cell lines from normal human mammary epithelial cells after exposure to benzo(a)pyrene (chemical carcinogenesis/differentiation/senescence/glucose metabolism/malignant progression)
TL;DR: In this article, the authors showed that the B(a)P-treated populations consistently contained cells displaying a longer period of active growth in culture compared to the untreated control cells.