TY  - JOUR
A1  - Rietjens, Ivonne M. C. M.
A1  - Dussort, P.
A1  - Günther, Helmut
A1  - Hanlon, Paul
A1  - Honda, Hiroshi
A1  - Mally, Angela
A1  - O'Hagan, Sue
A1  - Scholz, Gabriele
A1  - Seidel, Albrecht
A1  - Swenberg, James
A1  - Teeguarden, Justin
A1  - Eisenbrand, Gerhard
T1  - Exposure assessment of process-related contaminants in food by biomarker monitoring
JF  - Archives of Toxicology
N2  - Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state of the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario's and risk assessment, and (6) the possibilities of novel methodologies. In spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment.
KW  - Dietary process-related contaminants
KW  - Biomarkers
KW  - External exposure assessment
KW  - Physiologically based kinetic models
KW  - Risk assessment
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226268
VL  - 92
IS  - 1
ER  - 
TY  - JOUR
A1  - Dietzsch, Stefan
A1  - Braesigk, Annett
A1  - Seidel, Clemens
A1  - Remmele, Julia
A1  - Kitzing, Ralf
A1  - Schlender, Tina
A1  - Mynarek, Martin
A1  - Geismar, Dirk
A1  - Jablonska, Karolina
A1  - Schwarz, Rudolf
A1  - Pazos, Montserrat
A1  - Weber, Damien C.
A1  - Frick, Silke
A1  - Gurtner, Kristin
A1  - Matuschek, Christiane
A1  - Harrabi, Semi Ben
A1  - Glück, Albrecht
A1  - Lewitzki, Victor
A1  - Dieckmann, Karin
A1  - Benesch, Martin
A1  - Gerber, Nicolas U.
A1  - Obrecht, Denise
A1  - Rutkowski, Stefan
A1  - Timmermann, Beate
A1  - Kortmann, Rolf-Dieter
T1  - Types of deviation and review criteria in pretreatment central quality control of tumor bed boost in medulloblastoma—an analysis of the German Radiotherapy Quality Control Panel in the SIOP PNET5 MB trial
JF  - Strahlentherapie und Onkologie
N2  - Purpose
In Germany, Austria, and Switzerland, pretreatment radiotherapy quality control (RT-QC) for tumor bed boost (TB) in non-metastatic medulloblastoma (MB) was not mandatory but was recommended for patients enrolled in the SIOP PNET5 MB trial between 2014 and 2018. This individual case review (ICR) analysis aimed to evaluate types of deviations in the initial plan proposals and develop uniform review criteria for TB boost.

Patients and methods
A total of 78 patients were registered in this trial, of whom a subgroup of 65 patients were available for evaluation of the TB treatment plans. Dose uniformity was evaluated according to the definitions of the protocol. Additional RT-QC criteria for standardized review of target contours were elaborated and data evaluated accordingly.

Results
Of 65 initial TB plan proposals, 27 (41.5%) revealed deviations of target volume delineation. Deviations according to the dose uniformity criteria were present in 14 (21.5%) TB plans. In 25 (38.5%) cases a modification of the RT plan was recommended. Rejection of the TB plans was rather related to unacceptable target volume delineation than to insufficient dose uniformity.

Conclusion
In this analysis of pretreatment RT-QC, protocol deviations were present in a high proportion of initial TB plan proposals. These findings emphasize the importance of pretreatment RT-QC in clinical trials for MB. Based on these data, a proposal for RT-QC criteria for tumor bed boost in non-metastatic MB was developed.
KW  - brain tumor
KW  - pediatric
KW  - focal radiotherapy
KW  - quality assurance
KW  - individual case review
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-307812
SN  - 0179-7158
SN  - 1439-099X
VL  - 198
IS  - 3
ER  -