Multispectral tissue characterization in a RIF-1 tumor model: Monitoring the ADC and <I>T</I><SUB><FONT SIZE='-1'>2</FONT></SUB> responses to single-dose radiotherapy. Part II Export

@article{citeulike:4464590, abstract = {A multispectral (MS) approach that combines apparent diffusion coefficient (ADC) and T2 parameter maps with k-means (KM) clustering was employed to distinguish multiple compartments within viable tumor tissue (V1 and V2) and necrosis (N1 and N2) following single-dose (1000 cGy) radiotherapy in a radiation-induced fibrosarcoma (RIF-1) tumor model. The contributions of cell kill and tumor growth kinetics to the radiotherapy-induced response were investigated. A larger pretreatment V1 volume was correlated with decreased tumor growth delay (TGD) (r = 0.68) and cell kill (r = 0.71). There was no correlation for the pretreatment V2 volume. These results suggest that V1 tissue is well oxygenated and radiosensitive, whereas V2 tissue is hypoxic and therefore radioresistant. The relationship between an early ADC response and vasogenic edema and formation of necrosis was investigated. A trend for increased ADC was observed prior to an increase in the necrotic fraction (NF). Because there were no changes in T2, these observations suggest that the early increase in ADC is more likely based on a slight reduction in cell density, rather than radiation-induced vasogenic edema. Quantitative assessments of individual tissue regions, tumor growth kinetics, and cell kill should provide a more accurate means of monitoring therapy in preclinical animal models because such assessments can minimize the issue of intertumor variability. Magn Reson Med 57:513-519, 2007. {\copyright} 2007 Wiley-Liss, Inc.}, address = {Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, USA; Department of Clinical Sciences, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA; Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA; Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA}, author = {Henning, Erica C. and Azuma, Chieko and Sotak, Christopher H. and Helmer, Karl G.}, citeulike-article-id = {4464590}, citeulike-linkout-0 = {http://dx.doi.org/10.1002/mrm.21178}, citeulike-linkout-1 = {http://www3.interscience.wiley.com/cgi-bin/abstract/114130152/ABSTRACT}, doi = {10.1002/mrm.21178}, journal = {Magnetic Resonance in Medicine}, keywords = {clinical, diffusion, radiotherapy}, number = {3}, pages = {513--519}, posted-at = {2009-05-05 15:48:40}, priority = {2}, title = {Multispectral tissue characterization in a RIF-1 tumor model: Monitoring the ADC and <I>T</I><SUB><FONT SIZE='-1'>2</FONT></SUB> responses to single-dose radiotherapy. Part II}, url = {http://dx.doi.org/10.1002/mrm.21178}, volume = {57}, year = {2007} }

TY - JOUR ID - citeulike:4464590 L3 - citeulike-article-id:4464590 N2 - A multispectral (MS) approach that combines apparent diffusion coefficient (ADC) and T2 parameter maps with k-means (KM) clustering was employed to distinguish multiple compartments within viable tumor tissue (V1 and V2) and necrosis (N1 and N2) following single-dose (1000 cGy) radiotherapy in a radiation-induced fibrosarcoma (RIF-1) tumor model. The contributions of cell kill and tumor growth kinetics to the radiotherapy-induced response were investigated. A larger pretreatment V1 volume was correlated with decreased tumor growth delay (TGD) (r = 0.68) and cell kill (r = 0.71). There was no correlation for the pretreatment V2 volume. These results suggest that V1 tissue is well oxygenated and radiosensitive, whereas V2 tissue is hypoxic and therefore radioresistant. The relationship between an early ADC response and vasogenic edema and formation of necrosis was investigated. A trend for increased ADC was observed prior to an increase in the necrotic fraction (NF). Because there were no changes in T2, these observations suggest that the early increase in ADC is more likely based on a slight reduction in cell density, rather than radiation-induced vasogenic edema. Quantitative assessments of individual tissue regions, tumor growth kinetics, and cell kill should provide a more accurate means of monitoring therapy in preclinical animal models because such assessments can minimize the issue of intertumor variability. Magn Reson Med 57:513-519, 2007. © 2007 Wiley-Liss, Inc. IS - 3 JF - Magnetic Resonance in Medicine AD - Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, USA; Department of Clinical Sciences, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, USA; Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA; Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA EP - 519 TI - Multispectral tissue characterization in a RIF-1 tumor model: Monitoring the ADC and <I>T</I><SUB><FONT SIZE='-1'>2</FONT></SUB> responses to single-dose radiotherapy. Part II VL - 57 SP - 513 KW - clinical KW - diffusion KW - radiotherapy AU - Henning, Erica AU - Azuma, Chieko AU - Sotak, Christopher AU - Helmer, Karl PY - 2007/// UR - http://dx.doi.org/10.1002/mrm.21178 ER -