The response of mouse skin to irradiation with neutrons from the 62 MV cyclotron at Clatterbridge, U.K.

Joiner, Michael C.; Field, S. B.

doi:10.1016/0167-8140(88)90169-7

Cited by 26 publications

(7 citation statements)

References 24 publications

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“…Similar expressions were also presented by other authors (e.g. Joiner and Field 1988, Hawkins 1998, Dale and Jones 1999. The RBE in (4.2) depends on dose, which has to be the dose per fraction in a multifraction regime.…”

Section: The Phenomenological Rbe Modelsupporting

confidence: 74%

Evaluation of radiobiological effects in intensity modulated proton therapy: New strategies for inverse treatment planning

Wilkens

2004

Medical Physics

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Currently, treatment planning for intensity modulated proton therapy (IMPT) usually disregards variations of the relative biological effectiveness (RBE). To investigate the potential clinical relevance of a variable RBE for beam scanning techniques, new strategies for the evaluation of radiobiological effects and for the incorporation of the RBE into the inverse planning process are presented. These strategies are based on a fast algorithm for three‐dimensional calculations of the dose averaged linear energy transfer (LET) as a measure of the local radiation quality, and on a simple phenomenological approach for the RBE as a function of dose, LET and tissue type. It was found that the biological effect depended strongly on the type of scanning technique used, mainly due to differences in the LET distributions. New objective functions that account for LET and RBE were integrated into an inverse planning software, which now allows simultaneous multifield optimization of the biological effect in a reasonable time. With these methods, unfavorable RBE effects can be identified and compensated for by direct optimization of the product of RBE and dose, which is demonstrated for several clinical examples. The proposed strategies are therefore valuable tools to evaluate and improve the quality of treatment plans in IMPT.

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Section: The Phenomenological Rbe Modelsupporting

confidence: 74%

Evaluation of radiobiological effects in intensity modulated proton therapy: New strategies for inverse treatment planning

Wilkens

2004

Medical Physics

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“…The RBE increases with decreasing neutron energy. For very small doses/fraction, the RBE ranged from 3 to 4 for high-energy fast neutrons (42 MeV dþBe or 62 MeV pþBe Þ to approximately 8 for low-energy fast neutrons (4 MeV dþBe Þ. RBE values in the range of 1.5-4.0 are applicable for large single doses of !10 Gy Joiner and Field, 1988).…”

Section: Effectmentioning

confidence: 99%

ICRP PUBLICATION 118: ICRP Statement on Tissue Reactions and Early and Late Effects of Radiation in Normal Tissues and Organs — Threshold Doses for Tissue Reactions in a Radiation Protection Context

Stewart¹,

Akleyev²,

et al. 2012

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This report provides a review of early and late effects of radiation in normal tissues and organs with respect to radiation protection. It was instigated following a recommendation in Publication 103 (ICRP, 2007), and it provides updated estimates of 'practical' threshold doses for tissue injury defined at the level of 1% incidence. Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated, or chronic exposure. The organ systems comprise the haematopoietic, immune, reproductive, circulatory, respiratory, musculoskeletal, endocrine, and nervous systems; the digestive and urinary tracts; the skin; and the eye. Particular attention is paid to circulatory disease and cataracts because of recent evidence of higher incidences of injury than expected after lower doses; hence, threshold doses appear to be lower than previously considered. This is largely because of the increasing incidences with increasing times after exposure. In the context of protection, it is the threshold doses for very long follow-up times that are the most relevant for workers and the public; for example, the atomic bomb survivors with 40-50years of follow-up. Radiotherapy data generally apply for shorter follow-up times because of competing causes of death in cancer patients, and hence the risks of radiation-induced circulatory disease at those earlier times are lower. A variety of biological response modifiers have been used to help reduce late reactions in many tissues. These include antioxidants, radical scavengers, inhibitors of apoptosis, anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, growth factors, and cytokines. In many cases, these give dose modification factors of 1.1-1.2, and in a few cases 1.5-2, indicating the potential for increasing threshold doses in known exposure cases. In contrast, there are agents that enhance radiation responses, notably other cytotoxic agents such as antimetabolites, alkylating agents, anti-angiogenic drugs, and antibiotics, as well as genetic and comorbidity factors. Most tissues show a sparing effect of dose fractionation, so that total doses for a given endpoint are higher if the dose is fractionated rather than when given as a single dose. However, for reactions manifesting very late after low total doses, particularly for cataracts and circulatory disease, it appears that the rate of dose delivery does not modify the low incidence. This implies that the injury in these cases and at these low dose levels is caused by single-hit irreparable-type events. For these two tissues, a threshold dose of 0.5Gy is proposed herein for practical purposes, irrespective of the rate of dose delivery, and future studies may elucidate this judgement further.

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“…This justifies the vast number of studies and publications on secondary neutrons compared to secondary photons. 6,7,9,11,15,25,28 The overall fraction of proton energy that escapes by secondary neutrons and photons, range from 0.14% to 1.86% for incident proton beam-energy range 40-145 MeV. At energy of 110 MeV, this figure is about 1.00%.…”

Section: Production Of Secondary Neutrons and Photonsmentioning

confidence: 99%

“…Then, they used these organ-specific equivalent doses to calculate lifetime cancer risks, using standard techniques which were described in the US National Academy of sciences BIER-VII report, and other radiation risk reports. [13][14][15] They estimated the overall lifetime cancer risk for a 15-year-old boy at about 4.7% and for a 15year-old girl at about 11.1%. They indicated it to be larger for a younger patient and smaller for an older patient.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of energy deposition and secondary particle production in proton therapy of brain using a slab head phantom

Jia

Hadizadeh

Mowlavi

et al. 2014

Reports of Practical Oncology & Radiotherapy

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The response of mouse skin to irradiation with neutrons from the 62 MV cyclotron at Clatterbridge, U.K.

Cited by 26 publications

References 24 publications

Evaluation of radiobiological effects in intensity modulated proton therapy: New strategies for inverse treatment planning

Evaluation of radiobiological effects in intensity modulated proton therapy: New strategies for inverse treatment planning

ICRP PUBLICATION 118: ICRP Statement on Tissue Reactions and Early and Late Effects of Radiation in Normal Tissues and Organs — Threshold Doses for Tissue Reactions in a Radiation Protection Context

Evaluation of energy deposition and secondary particle production in proton therapy of brain using a slab head phantom

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