Proton RBE for early intestinal tolerance in mice after fractionated irradiation

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dc.contributor.authorGueulette J.
dc.contributor.authorSlabbert J.P.
dc.contributor.authorBohm L.
dc.contributor.authorDe Coster B.M.
dc.contributor.authorRosier J.-F.
dc.contributor.authorOctave-Prignot M.
dc.contributor.authorRuifrok A.
dc.contributor.authorNicolaas Schreuder A.
dc.contributor.authorWambersie A.
dc.contributor.authorScalliet P.
dc.contributor.authorJones D.T.L.
dc.date.accessioned2011-05-15T16:17:48Z
dc.date.available2011-05-15T16:17:48Z
dc.date.issued2001
dc.description.abstractBackground and purpose: To determine the influence of the number of fractions (or the dose per fraction) on the proton relative biological effectiveness (RBE). Materials and methods: Intestinal crypt regeneration in mice was used as the biological endpoint. RBE was determined relative to cobalt-60 gamma rays for irradiations in one, three and ten fractions separated by a time interval of 3.5 h. Proton irradiations were performed at the middle of a 7-cm Spread Out Bragg Peak (SOBP). Results: Proton RBEs (and corresponding gamma dose per fraction) at the level of 20 regenerated crypts per circumference were found equal to 1.15 ± 0.04 (10.0 Gy), 1.15 ± 0.05 (4.8 Gy) and 1.14 ± 0.07 (1.7 Gy) for irradiations in one, three and ten fractions, respectively. Alpha/beta ratios as derived from direct analysis of the 'quantal radiation response data' were found to be 7.6 Gy for gamma rays and 8.2 Gy for protons. Additional proton irradiations in ten fractions at the end of the SOBP were found to be more effective than at the middle of the SOBP by a factor of 1.14 (1.05-1.23). Conclusion: Proton RBE for crypt regeneration was found to be independent of fractionation up to ten fractions. One can expect that it remains unchanged for higher number of fractions as the lethalities for doses smaller than 3 Gy are exclusively due to direct lethal events. As a tendency for increased effectiveness at the end of the SOBP is reported in the majority of the studies, for clinical applications it would be advisable to allow for by arranging a sloping depth dose curve in the deeper part of the target volume. Finally, it must be noticed that most of in vitro and in vivo RBE values for protons are larger than the current clinical RBE (RBE = 1.10). © 2001 Elsevier Science Ireland Ltd. All rights reserved.
dc.description.versionArticle
dc.identifier.citationRadiotherapy and Oncology
dc.identifier.citation61
dc.identifier.citation2
dc.identifier.issn01678140
dc.identifier.other10.1016/S0167-8140(01)00446-7
dc.identifier.urihttp://hdl.handle.net/10019.1/14379
dc.subjectcobalt
dc.subjectproton
dc.subjectanimal experiment
dc.subjectarticle
dc.subjectcell regeneration
dc.subjectcontrolled study
dc.subjectcrypt cell
dc.subjectfemale
dc.subjectgamma radiation
dc.subjectintestine
dc.subjectmale
dc.subjectmouse
dc.subjectnonhuman
dc.subjectpriority journal
dc.subjectproton radiation
dc.subjectquantitative assay
dc.subjectradiation dose
dc.subjectradiation dose fractionation
dc.subjectradiation response
dc.subjectrelative biologic effectiveness
dc.subjectAnimals
dc.subjectDose Fractionation
dc.subjectFemale
dc.subjectGamma Rays
dc.subjectIntestines
dc.subjectMale
dc.subjectMice
dc.subjectMice, Inbred BALB C
dc.subjectProtons
dc.subjectRadiation Tolerance
dc.subjectRadiotherapy, High-Energy
dc.subjectRandom Allocation
dc.subjectRegeneration
dc.subjectWhole-Body Irradiation
dc.titleProton RBE for early intestinal tolerance in mice after fractionated irradiation
dc.typeArticle
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