In fast neutron therapy, the relative biological effectiveness (RBE) of a given beam varies to a large extent with the neutron energy spectrum. This spectrum depends primarily on the energy of the incident particles and on the nuclear reaction used for neutron production. However, it also depends on other factors which are specific to the local facility, eg, target, collimation system, etc. Therefore direct radiobiological intercomparisons are justified. The present paper reports the results of an intercomparison performed at seven neutrontherapy centres: Orléans, France (p(34)+Be), Riyadh, Saudi Arabia (p(26)+Be), Ghent, Belgium (d(14.5)+Be), Faure, South Africa (p(66)+Be), Detroit, USA (d(48)+Be), Nice, France (p(65)+Be) and Louvain-la-Neuve, Belgium (p(65)+Be). The selected radiobiological system was intestinal crypt regeneration in mice after single fraction irradiation. The observed RBE values (ref cobalt-60 gamma-rays) were 1.79 +/- 0.10, 1.84 +/- 0.07, 2.24 +/- 0.11, 1.55 +/- 0.04, 1.51 +/- 0.03, 1.50 +/- 0.04 and 1.52 +/- 0.04, respectively. When machine availability permitted, additional factors were studied: two vs one fraction (Ghent, Louvain-la-Neuve), dose rate (Detroit), influence of depth in phantom (Faure, Detroit, Nice, Louvain-la-Neuve). In addition, at Orléans and Ghent, RBEs were also determined for LD50 at 6 days after selective abdominal irradiation and were found to be equal to the RBEs for crypt regeneration. The radiobiological intercomparisons were always combined with direct dosimetric intercomparisons and, when possible in some centres, with microdosimetric investigations.

Download full-text PDF

Source
http://dx.doi.org/10.1016/0924-4212(96)84886-9DOI Listing

Publication Analysis

Top Keywords

+/- 004
12
fast neutron
8
radiobiological intercomparisons
8
crypt regeneration
8
+/-
7
rbe variation
4
variation fast
4
neutron
4
neutron beams
4
beams function
4

Similar Publications

The Association Between Hearing Loss and Depression in a Large Electronic Health Record System.

Otolaryngol Head Neck Surg

January 2025

Department of Otolaryngology-Head and Neck Surgery, Columbia University Vagelos College of Physicians and Surgeons,  NewYork-Presbyterian/Columbia University Irving Medical Center, New York, New York, USA.

Objective: Hearing loss (HL) is associated with depression, but existing datasets are limited by the type of data available for both hearing and mental health conditions. The purpose of this study is to determine if there is an association between HL and depressive disorders within a large bi-institutional electronic health record (EHR) system containing more granular diagnostic information.

Study Design: Cross-sectional epidemiologic study.

View Article and Find Full Text PDF

Research suggests that folic acid contributes to improving cognitive function. However, there is a lack of systematic research on the association of dietary intake of folate and serum, and red blood cell (RBC) folate levels with global cognitive impairment (CoI) in the elderly population. Importantly, excessive supplementation with folate among American adults at high risk of cardiovascular disease (CVD) may have harmful effects.

View Article and Find Full Text PDF

Background: We launched the Wako Cohort Study in 2023 to identify individual and socio-environmental factors related to the extension of healthy life expectancy and the reduction of health disparities among community-dwelling adults and to develop health promotion and care prevention strategies. This study profile aims to describe the study design and participants' profile at baseline.

Methods: The Wako Cohort Study is a prospective study of community-dwelling adults aged ≥ 40 years living in Wako City, Saitama Prefecture, Japan.

View Article and Find Full Text PDF

Purpose: To determine the effect of low hypermetropia correction and orthoptic exercises on binocular visual function in children with symptomatic convergence insufficiency.

Methods: This was a prospective, randomized intervention with a 3-month follow-up. Consecutive pediatric patients with convergence insufficiency and hypermetropia who met inclusion criteria were randomly assigned to one of three treatment groups: spectacle correction and orthoptic training (group 1), spectacle correction alone (group 2) and orthoptic training alone (group 3).

View Article and Find Full Text PDF

Early-Life Antibiotic Exposures: Paving the Pathway for Dysbiosis-Induced Disorders.

Eur J Pharmacol

January 2025

School of Pharmaceutical Sciences, Universiti Sains Malaysia, Gelugor, 11800, Penang, Malaysia. Electronic address:

Microbiota encompasses a diverse array of microorganisms inhabiting specific ecological niches. Gut microbiota significantly influences physiological processes, including gastrointestinal motor function, neuroendocrine signalling, and immune regulation. They play a crucial role in modulating the central nervous system and bolstering body defence mechanisms by influencing the proliferation and differentiation of innate and adaptive immune cells.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!