Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans : joint RENEB and EURADOS inter-laboratory comparisons

Purpose: RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. Materials and methods: The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation induced thermoluminescent signals in glass screens taken from mobile phones. Results: In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. Conclusions: Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios

Comparable dose estimates of blinded whole blood samples are obtained independently of culture conditions and analytical approaches. Second RENEB gene expression study

PURPOSE:This collaboration of five established European gene expression labs investigated the potential impact of culture conditions on the transcriptional response of peripheral blood to radiation exposure.MATERIALS AND METHODS:Blood from one healthy donor was exposed ex vivo to a Cobalt 60 source to produce a calibration curve in addition to four unknown doses. After exposure, the blood samples were either diluted with RPMI medium or left untouched. After 24-h incubation at 37 °C the diluted blood samples were lysed, while the undiluted samples were mixed with the preservative RNALater and all samples were shipped frozen to the participating labs. Samples were processed by each lab using microarray (one lab) and QRT-PCR (four labs).RESULTS:We show that although culture conditions affect the total amount of RNA recovered (p 0.5 Gy) measurements (p = .6).CONCLUSION:This study confirms the robustness of gene expression as a method for biological dosimetry

The first in vivo multiparametric comparison of different radiation exposure biomarkers in human blood.

The increasing risk of acute large-scale radiological/nuclear exposures of population underlines the necessity of developing new, rapid and high throughput biodosimetric tools for estimation of received dose and initial triage. We aimed to compare the induction and persistence of different radiation exposure biomarkers in human peripheral blood in vivo. Blood samples of patients with indicated radiotherapy (RT) undergoing partial body irradiation (PBI) were obtained soon before the first treatment and then after 24 h, 48 h, and 5 weeks; i.e. after 1, 2, and 25 fractionated RT procedures. We collected circulating peripheral blood from ten patients with tumor of endometrium (1.8 Gy per fraction) and eight patients with tumor of head and neck (2.0-2.121 Gy per fraction). Incidence of dicentrics and micronuclei was monitored as well as determination of apoptosis and the transcription level of selected radiation-responsive genes. Since mitochondrial DNA (mtDNA) has been reported to be a potential indicator of radiation damage in vitro, we also assessed mtDNA content and deletions by novel multiplex quantitative PCR. Cytogenetic data confirmed linear dose-dependent increase in dicentrics (p < 0.01) and micronuclei (p < 0.001) in peripheral blood mononuclear cells after PBI. Significant up-regulations of five previously identified transcriptional biomarkers of radiation exposure (PHPT1, CCNG1, CDKN1A, GADD45, and SESN1) were also found (p < 0.01). No statistical change in mtDNA deletion levels was detected; however, our data indicate that the total mtDNA content decreased with increasing number of RT fractions. Interestingly, the number of micronuclei appears to correlate with late radiation toxicity (r2 = 0.9025) in endometrial patients suggesting the possibility of predicting the severity of RT-related toxicity by monitoring this parameter. Overall, these data represent, to our best knowledge, the first study providing a multiparametric comparison of radiation biomarkers in human blood in vivo, which have potential for improving biological dosimetry

Single-course bleomycin, etoposide, and cisplatin (1xBEP) as adjuvant treatment in testicular nonseminoma clinical stage 1: outcome, safety, and risk factors for relapse in a population-based study

INTRODUCTION: Clinical stage 1 (CS1) nonseminomatous (NS) germ cell tumors involve a 30% probability of relapse upon surveillance. Adjuvant chemotherapy with one course of bleomycin, etoposide, and cisplatin (1xBEP) can reduce this risk to pT2 was significantly associated with relapse rate. CONCLUSION: The relapse rate of 3.1% found in this population of NS CS1 patients treated with 1xBEP at the routine care level was not inferior to the median rate of 2.3% reported from a meta-analysis of controlled trials. Also, the cure rate of relapses of 77% is consistent with the previously reported rate of 80%. This study clearly shows that the 1xBEP regimen represents a safe treatment for NS CS1 patients

Transcriptional modification of expression of radiation-responsive genes in head and neck patients.

<p>Transparent symbols represent QRT-PCR fold change in expression of the genes PHPT (A), CCNG1 (B), CDKN1A (C), GADD45 (D), and SESN1 (E) for eight head and neck cancer patients before (0) and after 1, 2, and 25 fractions of radiotherapy (RT). The mean (± SEM) is shown as non-transparent symbols. Gene expression is given as fold change relative to unexposed Control sample set at 1 (normalized against the housekeeping gene, HPRT). **, statistically significant difference versus Control group (p < 0.01); ***, statistically significant difference versus Control group (p < 0.005). For GADD45 p-trend was applied (r² = 0.980).</p

Chromosomal changes in PBMCs of head and neck patients.

<p>Number of dicentric chromosomes (A) and structurally aberrant cells (B) was determined and both parameters increase with the number of RT fractions. *, statistically significant difference versus Control group (p < 0.01). Representative figures of dicentric chromosome (C) and structurally aberant cells—ring chromosome (D), double fragment (E) and break (F) are shown.</p

Induction and persistence of different biomarkers.

<p>Graphs showing the induction and temporal persistence of the biomarkers studied in endometrial (A) and head and neck patients (B). In order to compare all the parameters studied, the highest value detected was arbitrary set as 100%. Established cytogenetic markers and mtDNA content are suitable for late time points after irradiation while the new biomarkers as radiation-induced genes are more informative atearly time-points after radiation exposure. mt Maj, data from mtDNA content analysis of mtMajArch; mt Min, data from mtDNA content analysis of mtMinArch; gene expression, data from MQRT-PCR (average of five genes); micronuclei, data from micronuclei assay; aberrations, data from structural aberration analyses; dicentrics, data from dicentric chromosomes assay; apoptosis, data from flow-cytometric detection of apoptotic cells in lymphocyte population (percentage of apoptotic cells versus healthy-intact cells set as 100%).</p

The amount of mtDNA content.

<p>mtDNA was quantified in the minor arc (mtMin) and in the major arc (mtMaj) site. The data indicate the relative decrease in mtDNA content over the time in both groups of the endometrial (A) and (B) and head and neck (C) and (D) patients. Upper and lower quartiles with median are shown. Black rhombs represent arithmetic mean; *, statistically significant difference between 25^th RT fraction and Control group (p < 0.05).</p