Document Detail

Early reoxygenation in tumors after irradiation: determining factors and consequences for radiotherapy regimens using daily multiple fractions.
MedLine Citation:
PMID:  16199320     Owner:  NLM     Status:  MEDLINE    
PURPOSE: To characterize changes in the tumor microenvironment early after irradiation and determine the factors responsible for early reoxygenation. METHODS AND MATERIALS: Fibrosarcoma type II (FSaII) and hepatocarcinoma transplantable liver tumor tumor oxygenation were determined using electron paramagnetic resonance oximetry and a fiberoptic device. Perfusion was assessed by laser Doppler, dynamic contrast-enhanced MRI, and dye penetration. Oxygen consumption was determined by electron paramagnetic resonance. The interstitial fluid pressure was evaluated by the wick-in-needle technique. RESULTS: An increase in oxygen partial pressure was observed 3-4 h after irradiation. This increase resulted from a decrease in global oxygen consumption and an increase in oxygen delivery. The increase in oxygen delivery was due to radiation-induced acute inflammation (that was partially inhibited by the antiinflammatory agent diclofenac) and to a decrease in interstitial fluid pressure. The endothelial nitric oxide synthase pathway, identified as a contributing factor at 24 h after irradiation, did not play a role in the early stage after irradiation. We also observed that splitting a treatment of 18 Gy into two fractions separated by 4 h (time of maximal reoxygenation) had a greater effect on tumor regrowth delay than when applied as a single dose. CONCLUSION: Although the cell cycle redistribution effect is important for treatment protocols using multiple daily radiation fractions, the results of this work emphasize that the oxygen effect must be also considered to optimize the treatment strategy.
Nathalie Crokart; Bénédicte F Jordan; Christine Baudelet; Reginald Ansiaux; Pierre Sonveaux; Vincent Grégoire; Nelson Beghein; Julie DeWever; Caroline Bouzin; Olivier Feron; Bernard Gallez
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  International journal of radiation oncology, biology, physics     Volume:  63     ISSN:  0360-3016     ISO Abbreviation:  Int. J. Radiat. Oncol. Biol. Phys.     Publication Date:  2005 Nov 
Date Detail:
Created Date:  2005-10-03     Completed Date:  2005-12-09     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7603616     Medline TA:  Int J Radiat Oncol Biol Phys     Country:  United States    
Other Details:
Languages:  eng     Pagination:  901-10     Citation Subset:  IM    
Laboratory of Medicinal Chemistry and Radiopharmacy, Université Catholique de Louvain, Brussels, Belgium.
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MeSH Terms
Carcinoma, Hepatocellular / blood supply,  metabolism,  radiotherapy
Dose Fractionation
Extracellular Fluid / physiology
Fibrosarcoma / blood supply,  metabolism,  radiotherapy
Liver Neoplasms / blood supply,  metabolism,  radiotherapy
Mice, Inbred C3H
Neoplasms / blood supply,  metabolism*,  radiotherapy*
Nitric Oxide Synthase Type III / metabolism
Oximetry / methods
Oxygen Consumption / physiology,  radiation effects*
Partial Pressure
Radiation Tolerance
Time Factors
Reg. No./Substance:
EC Oxide Synthase Type III

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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