AIM To compare therapeutic responses of a vascular-disrupting-agent, combretastatin-A4-phosphate(CA4 P), among hepatocellular carcinomas(HCCs) and implanted rhabdomyosarcoma(R1) in the same rats by magneticresonance-i...AIM To compare therapeutic responses of a vascular-disrupting-agent, combretastatin-A4-phosphate(CA4 P), among hepatocellular carcinomas(HCCs) and implanted rhabdomyosarcoma(R1) in the same rats by magneticresonance-imaging(MRI), microangiography and histopathology.METHODS Thirty-six HCCs were created by diethylnitrosamine gavage in 14 rats that were also intrahepatically implanted with one R1 per rat as monitored by T2-/T1-weighted images(T2wI/T1wI) on a 3.0 T clinical MRIscanner. Vascular response and tumoral necrosis were detected by dynamic contrast-enhanced(DCE-) and CE-MRI before, 1 h after and 12 h after CA4P iv at 10 mg/kg(treatment group n = 7) or phosphate-buffered saline at 1.0 mL/kg(control group n = 7). Tumor blood supply was calculated by a semiquantitative DCE parameter of area under the time signal intensity curve(AUC30). In vivo MRI findings were verified by postmortem techniques.RESULTS On CE-T1wIs, unlike the negative response in all tumors of control animals, in treatment group CA4P caused rapid extensive vascular shutdown in all R1-tumors, but mildly or spottily in HCCs at 1 h. Consequently, tumor necrosis occurred massively in R1-tumors but patchily in HCCs at 12 h. AUC30 revealed vascular closure(66%) in R1-tumors at 1 h(P < 0.05), followed by further perfusion decrease at 12 h(P < 0.01), while less significant vascular clogging occurred in HCCs. Histomorphologically, CA4P induced more extensive necrosis in R1-tumors(92.6%) than in HCCs(50.2%)(P < 0.01); tumor vascularity heterogeneously scored +^+++ in HCCs but homogeneously scored ++ in R1-tumors.CONCLUSION This study suggests superior performance of CA4P in metastatic over primary liver cancers, which could guide future clinical applications of vascular-disruptingagents.展开更多
AIM:To explore whether the antitumor effect of a vascular disrupting agent(VDA)would be enhanced by combining with an antiangiogenic agent,and whether such synergistic effects can be effectively evaluated with separat...AIM:To explore whether the antitumor effect of a vascular disrupting agent(VDA)would be enhanced by combining with an antiangiogenic agent,and whether such synergistic effects can be effectively evaluated with separate calculation of diffusion weighted magnetic resonance imaging(DW-MRI).METHODS:Thirty-seven rats with implanted liver tumors were randomized into the following three groups:(1)ZD6126,a kind of VDA;(2)ZDTHA,ZD6126 in combination with an antiangiogenic,thalidomide;and(3)control.Morphological DW-MRI were performed and quantified before,4 h and 2 d after treatment.The apparent diffusion coefficient(ADC)values were calculated separately for low b values(ADC low),high b values(ADC high)and all b values(ADC all).The tissue perfusion contribution,ADC perf,was calculated as ADC low-ADC high.Imaging findings were finally verified by histopathology.RESULTS:The combination therapy with ZDTHA significantly delayed tumor growth due to synergistic effects by inducing cumulative tumor necrosis.In addition to delaying tumor growth,ZDTHA caused tumor necrosis in an additive manner,which was verified by HE staining.Although both ADC high and ADC all in the ZD6126and ZDTHA groups were significantly higher compared to those in the control group on day 2,the entire tumor ADC high of ZDTHA was even higher than that of ZD6126,but the significant difference was not observed for ADCall between ZDTHA and ZD6126.This indicated that the perfusion insensitive ADC high values calculated from high b value images performed significantly better than ADC all for the monitoring of tumor necrosis on day 2.The perfusion sensitive ADC perf derived from ADC low by excluding high b value effects could better reflect the reduction of blood flow due to the vessel shutdown induced by ZD6126,compared to the ADC low at 4 h.The ADC perf could provide valuable perfusion information from DW-MRI data.CONCLUSION:The separate calculation of ADC is more useful than conventional averaged ADC in evaluating the efficacy of combination therapy with ZD6126and thalidomide for solid tumors.展开更多
文摘AIM To compare therapeutic responses of a vascular-disrupting-agent, combretastatin-A4-phosphate(CA4 P), among hepatocellular carcinomas(HCCs) and implanted rhabdomyosarcoma(R1) in the same rats by magneticresonance-imaging(MRI), microangiography and histopathology.METHODS Thirty-six HCCs were created by diethylnitrosamine gavage in 14 rats that were also intrahepatically implanted with one R1 per rat as monitored by T2-/T1-weighted images(T2wI/T1wI) on a 3.0 T clinical MRIscanner. Vascular response and tumoral necrosis were detected by dynamic contrast-enhanced(DCE-) and CE-MRI before, 1 h after and 12 h after CA4P iv at 10 mg/kg(treatment group n = 7) or phosphate-buffered saline at 1.0 mL/kg(control group n = 7). Tumor blood supply was calculated by a semiquantitative DCE parameter of area under the time signal intensity curve(AUC30). In vivo MRI findings were verified by postmortem techniques.RESULTS On CE-T1wIs, unlike the negative response in all tumors of control animals, in treatment group CA4P caused rapid extensive vascular shutdown in all R1-tumors, but mildly or spottily in HCCs at 1 h. Consequently, tumor necrosis occurred massively in R1-tumors but patchily in HCCs at 12 h. AUC30 revealed vascular closure(66%) in R1-tumors at 1 h(P < 0.05), followed by further perfusion decrease at 12 h(P < 0.01), while less significant vascular clogging occurred in HCCs. Histomorphologically, CA4P induced more extensive necrosis in R1-tumors(92.6%) than in HCCs(50.2%)(P < 0.01); tumor vascularity heterogeneously scored +^+++ in HCCs but homogeneously scored ++ in R1-tumors.CONCLUSION This study suggests superior performance of CA4P in metastatic over primary liver cancers, which could guide future clinical applications of vascular-disruptingagents.
基金Supported by National Natural Science Foundation of China,No.30670603
文摘AIM:To explore whether the antitumor effect of a vascular disrupting agent(VDA)would be enhanced by combining with an antiangiogenic agent,and whether such synergistic effects can be effectively evaluated with separate calculation of diffusion weighted magnetic resonance imaging(DW-MRI).METHODS:Thirty-seven rats with implanted liver tumors were randomized into the following three groups:(1)ZD6126,a kind of VDA;(2)ZDTHA,ZD6126 in combination with an antiangiogenic,thalidomide;and(3)control.Morphological DW-MRI were performed and quantified before,4 h and 2 d after treatment.The apparent diffusion coefficient(ADC)values were calculated separately for low b values(ADC low),high b values(ADC high)and all b values(ADC all).The tissue perfusion contribution,ADC perf,was calculated as ADC low-ADC high.Imaging findings were finally verified by histopathology.RESULTS:The combination therapy with ZDTHA significantly delayed tumor growth due to synergistic effects by inducing cumulative tumor necrosis.In addition to delaying tumor growth,ZDTHA caused tumor necrosis in an additive manner,which was verified by HE staining.Although both ADC high and ADC all in the ZD6126and ZDTHA groups were significantly higher compared to those in the control group on day 2,the entire tumor ADC high of ZDTHA was even higher than that of ZD6126,but the significant difference was not observed for ADCall between ZDTHA and ZD6126.This indicated that the perfusion insensitive ADC high values calculated from high b value images performed significantly better than ADC all for the monitoring of tumor necrosis on day 2.The perfusion sensitive ADC perf derived from ADC low by excluding high b value effects could better reflect the reduction of blood flow due to the vessel shutdown induced by ZD6126,compared to the ADC low at 4 h.The ADC perf could provide valuable perfusion information from DW-MRI data.CONCLUSION:The separate calculation of ADC is more useful than conventional averaged ADC in evaluating the efficacy of combination therapy with ZD6126and thalidomide for solid tumors.
