Radiation research. Supplement最新文献

{"title":"Neoplastic cell transformation by heavy charged particles.","authors":"T C Yang,&nbsp;L M Craise,&nbsp;M T Mei,&nbsp;C A Tobias","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>With confluent cultures of the C3H10T1/2 mammalian cell line, we have investigated the effects of heavy-ion radiation on neoplastic cell transformation. Our quantitative data obtained with high-energy carbon, neon, silicon, argon, iron, and uranium particles show that RBE is both dose- and LET-dependent for malignant cell transformation. RBE is higher at lower doses. There is an increase of RBE with LET, up to about 100-200 keV/micron, and a decrease of RBE with beams of higher LET values. Transformation lesions induced by heavy particles with LET values greater than 100 keV/micron may not be repairable in nonproliferating cells. RBE for slow and nonproliferating cells may be much higher than for actively growing cells.</p>","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"8 ","pages":"S177-87"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14984027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The repair-misrepair model in radiobiology: comparison to other models.","authors":"C A Tobias","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Biological phenomena related to the inactivation of eukaryotic cells by noxious agents have been formulated mathematically in the repair-misrepair (RMR) model by separately quantitating the initial submicroscopic production of molecular lesions and the later, macroscopic expression of effects in the course of cell progression and repair. This paper presents some conceptual and quantitative similarities and differences between the RMR and seven other models proposed for cellular radiobiology including: the linear-quadratic, three-lambda, cubic-survival, target theory, hit-size probability, cybernetic, and lethal-potentially lethal models. The comparison of the various approaches has shown that the RMR model can be generalized to show relationships with each.</p>","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"8 ","pages":"S77-95"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14985211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chronic effects of neutrons and charged particles on spinal cord, lung, and rectum.","authors":"A. J. van der Kogel","doi":"10.2307/3583529","DOIUrl":"https://doi.org/10.2307/3583529","url":null,"abstract":"The effects of multifraction irradiation with X rays, neutrons, and pions on the rat cervical and lumbar spinal cord, mouse lung, and rat rectum have been investigated. The linear-quadratic model was used to analyze the effectiveness per unit dose for various tissue responses. It is concluded that the dependence of tolerance doses on fraction size is considerably reduced for both intermediate (pions) and high-LET (neutrons) radiations, as shown by the observed alpha/beta ratios in the range of 20-50. With accurately defined alpha/beta values for various tissues and types of radiation, the same tolerance formalisms can be used as proposed for low-LET radiation. The effectiveness of pion irradiation shows a significant dependence on dose rate when treatment times are long and repair of subeffective damage occurs during the irradiations. For late effects in spinal cord, lung, and rectum, RBE values of pions are 1.5 or less at doses per fraction in the range of 1.2-4.5 Gy.","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"5 1","pages":"S208-16"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77030649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heavy charged-particle Bragg peak radiosurgery for intracranial vascular disorders.","authors":"J. Fabrikant, J. Lyman, K. Frankel","doi":"10.2307/3576654","DOIUrl":"https://doi.org/10.2307/3576654","url":null,"abstract":"The program at Donner Pavilion has applied nuclear medicine research to the diagnosis and radiosurgical treatment of life-threatening intracranial vascular disorders that affect approximately one million Americans. Stereotactic heavy-ion Bragg peak radiosurgery, using narrow beams of heavy ions (helium), demonstrates superior biological and physical characteristics in brain over X and gamma rays and protons, viz., improved dose distribution in the Bragg peak, sharp lateral and distal borders, and less multiple scattering and range straggling for the same residual range in CNS tissue. Examination of CNS tissue response and alteration of cerebral blood-flow dynamics related to heavy-ion Bragg peak radiosurgery is being undertaken using three-dimensional treatment planning and quantitative imaging utilizing cerebral angiography, computerized tomography (CT), magnetic resonance imaging (MRI), cine-CT, xenon X-ray CT, and positron emission tomography (PET). Also under examination are the physical properties of narrow heavy-ion beams for improving methods of dose delivery and dose distribution and for establishing clinical RBE/LET and dose-response relationships for human CNS tissues. Based on the evaluation and treatment with stereotactically directed narrow beams of heavy ions of over 130 patients, with cerebral angiography and CT scanning, and with MRI and radioisotope scanning of selected patients, plus extensive clinical and neuroradiological follow-up, it appears that heavy-ion radiosurgery obliterates intracranial arteriovenous malformations or protects against rebleeding with reduced morbidity and mortality.","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"1 1","pages":"S244-58"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79541730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Charged particle cytogenetics: effects of LET, fluence, and particle separation on chromosome aberrations.","authors":"C R Geard","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Induced rearrangements of chromosomes, disrupting the orderly sequence and/or separation of the genetic material, are responsible for a significant proportion of cellular lethality, genetic mutation, and, as has become increasingly apparent in recent years, human cancer. The quantitative observation of chromosomal aberrations induced by ionizing radiations led early to the realization that as linear energy transfer (LET) increased, curvilinear dose responses became increasingly linear. Those few studies that examined aberrations as a function of LET found that the optimally effective LET was about 100 keV per micrometer, results consistent with those observed for other end points. The majority of chromosomal aberrations originate from molecular interaction between pairs of lesions (misrepair), with differences in sensitivity to aberration induction through the cell cycle. In Chinese hamster V-79 cells for all LET values studied, aberrations are most frequent in G2, then G1, then S phase of the cell cycle. The variation in sensitivity through the cell cycle changes from a factor of about 5 for 10 keV/micron particles to about 3 for 80 keV/micron particles. In the G2 phase a curvilinear dose response (G1 and S being linear) is found for all LETs occurring at fluences where there are substantial distances (greater than or equal to 3 micron) between particles. It is possible that for this one phase of the cell cycle a saturation of repair capabilities occurs as a function of both fluence and LET. When cells were irradiated with associated charged particles (molecular ions) it was found that even when two particles were separated by distances of less than 100 nm their effect was much less than one particle of twice the LET (the equivalent of 0 distance separation). This implies that the vast majority of molecular interactions which result in chromosomal aberrations occur as a consequence of interaction between damaged sites formed only a few nanometers from each other. It is clear that an analysis of chromosomal aberrations produced by charged particles can provide considerable insight into basic radiobiological mechanisms and into the organization of the mammalian genome.</p>","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"8 ","pages":"S112-21"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14137022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heavy-ion effects on mammalian cells: inactivation measurements with different cell lines.","authors":"H Wulf,&nbsp;W Kraft-Weyrather,&nbsp;H G Miltenburger,&nbsp;E A Blakely,&nbsp;C A Tobias,&nbsp;G Kraft","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In track segment experiments, the inactivation of different mammalian cells by heavy charged particles between helium and uranium in the energy range between 1 and 1000 MeV/u has been measured at the heavy ion accelerator Unilac, Darmstadt, the Tandem Van de Graaf, Heidelberg, and the Bevalac, Berkeley. The inactivation cross sections calculated from the final slope of the dose-effect curves are given as a function of the particle energy and the linear energy transfer.</p>","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"8 ","pages":"S122-34"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14984023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lethal, potentially lethal, and nonlethal damage induction by heavy ions in cultured human cells.","authors":"P Todd,&nbsp;J C Wood,&nbsp;J T Walker,&nbsp;S J Weiss","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In the fields of high-LET radiotherapy and space radiation safety it is important to know the relative probabilities with which a cell whose nucleus is struck by a heavy ion will be damaged or killed. Experiments were performed in which synchronous cultured human T-1 cells (presumptive HeLa) were irradiated with natural alpha particles of energy approximately 3.5 MeV at various times after mitotic selection up to the middle of S phase. Nuclear-area histograms were determined as a function of time after mitosis under conditions identical to those used for irradiation. The efficiency with which one particle passing through the nucleus killed a cell was found to be 0.14-0.20. This value was extrapolated to experimental cell survival data obtained when asynchronous cultured human cells were irradiated with He, Li, B, C, N, O, Ne, Ar ions of energy 6.58 or 5.5 MeV/amu, and the cell killing efficiency was found to be in the broad range of 0.5-1.0 under single-hit conditions. Similarly irradiated cells were examined for colony-size distribution by an image analysis technique, and it was found that the loss of large colonies was dose and LET-dependent in a systematic way. Dose-response data suggest two predominant subpopulations, resistant and sensitive cells, and it appears that the sensitive population is affected by single-hit kinetics. The single-hit coefficient for the induction of inherited slow growth varied with LET in a similar way to that for survival. The action cross section for this form of heritable damage appears to be comparable to the geometric cross section of the cell nucleus.(ABSTRACT TRUNCATED AT 250 WORDS)</p>","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"8 ","pages":"S5-12"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14985207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Possible damage of repair systems by Pi-mesons of different LET spectra.","authors":"H Fritz-Niggli,&nbsp;C Buechi,&nbsp;K Schaeppi","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Pi-meson experiments with repair-deficient spermatides and oocytes of Drosophila melanogaster have permitted a study of the LET dependence of the repair of different types of chromosomal lesions. The data show a distinction between primary events connected with fusion modalities (repair or misrepair) and those associated with no fusion. Repair deficiency increases the induction of chromosomal loss and dominant lethality (early damage) and decreases the induction of translocations (misrepair), perhaps responsible for late effects. The induction of nonfusion events is higher for pions compared to X rays and increases with mean lineal energy spectra, whereas the production of translocations is maximal at intermediate ionization density. The direct damage of repair systems by high-LET pions is postulated to explain these observations.</p>","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"8 ","pages":"S165-71"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15051967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current considerations in heavy charged-particle radiotherapy: a clinical research trial of the University of California Lawrence Berkeley Laboratory, Northern California Oncology Group, and Radiation Therapy Oncology Group.","authors":"J R Castro,&nbsp;G T Chen,&nbsp;E A Blakely","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Phase I and II radiotherapy trials with accelerated high-energy heavy charged-particle beams have been carried out at the University of California Lawrence Berkeley Laboratory in conjunction with the Northern California Oncology Group and the Radiation Therapy Oncology Group. Clinical experience with several anatomical regions and tumor types has been accumulated. Preliminary observations suggest that toxicity is acceptable with treatment techniques developed for neon ions. Further data must be accumulated for carbon or silicon ion therapy. Initial Phase III trials with neon ions should begin shortly; evaluation of optimal ions and techniques for improved dose localization is ongoing. Future directions for optimization of heavy charged-particle radiotherapy are presented.</p>","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"8 ","pages":"S263-71"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15051970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calculation of heavy-ion tracks in liquid water.","authors":"R. Hamm, J. Turner, R. H. Ritchie, H. Wright","doi":"10.2307/3576627","DOIUrl":"https://doi.org/10.2307/3576627","url":null,"abstract":"Detailed Monte Carlo calculations are presented of proton and alpha-particle tracks in liquid water. The computations treat the interactions of the primary particle and all secondary electrons on a statistical, event-by-event basis to simulate the initial physical changes that accompany the passage of an ion through water. Our methods for obtaining the cross sections needed for such calculations are described. Inelastic scattering probabilities (inverse mean free paths) are derived from a complex dielectric response function constructed for liquid water, based on experimental and theoretical data. Examples of partial cross sections for ionization and excitation by protons are shown. The computation of electron transport and energy loss includes exchange, elastic scattering, and a scheme for the delocalization of energy shared collectively by a large number of electrons in the condensed medium. Several examples of calculated proton and alpha-particle tracks are presented and discussed. The meaning and significance of the concept of a track core are briefly addressed in the light of this work. The present paper treats only the initial, physical changes produced by radiation in water (in approximately 10(-15) s in local regions of a track). The work described here is used in calculations that we have reported in other publications on the later chemical development of charged-particle tracks.","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"9 1","pages":"S20-6"},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74691685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}