Shao Haibo, Ni Yicheng, Zhang Jian, Chen Feng, Dai Xu, Fan Guoguang, Sun Ziping, Xu Ke
Department of Radiology, the First Affiliated Hospital of China Medical University, Shenyang, China.
Section of Radiology, Department of Medical Diagnostic Science, University of Leuven, Leuven, Belgium.
PLoS One. 2013 Dec 23;8(12):e82649. doi: 10.1371/journal.pone.0082649. eCollection 2013.
Evaluation of vascular disrupting treatment (VDT) is generally based on tumor size and enhancement on conventional magnetic resonance imaging (MRI) which, unfortunately, may be limited in providing satisfactory information. The purpose of the study is to evaluate consecutive changes of 20 rabbit VX2 liver tumors after VDT by dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) at a 3.0 T MR unit. Twenty four hours after intravenous injection of Combretastatin A-4-phosphate (CA4P) at 20 mg/kg, DCE-MRI derived Maximum Slope of Increase (MSI) and Positive Enhancement Integral (PEI) decreased sharply due to sudden shutting down of tumor feeding vessels. DWI derived Apparent Diffusion Coefficient (ADC) in tumor periphery decreased because of ischemic cell edema. On day 4, an increase of MSI was probably caused by the recovery of blood supply. A remarkable increase of ADC represented a large scale of necrosis among tumors. On day 8, the blood perfusion further decreased and the extent of necrosis further increased, reflected by lower MSI and PEI values and higher ADC value. On day 12, a second decrease of ADC was noticed because the re-growth of periphery tumor. The experimental data indicate that the therapeutic effects of VDT may be noninvasively monitored with DCE-MRI (reflecting tumor blood perfusion) and DWI (reflecting the changes of histology), which provide powerful measures for assessment of anticancer treatments.
血管破坏治疗（VDT）的评估通常基于传统磁共振成像（MRI）上的肿瘤大小和强化情况，然而遗憾的是，这在提供满意信息方面可能存在局限性。本研究的目的是在3.0 T磁共振设备上，通过动态对比增强磁共振成像（DCE-MRI）和扩散加权成像（DWI）评估20只兔VX2肝肿瘤在VDT后的连续变化。以20 mg/kg静脉注射磷酸羟基喜树碱（CA4P）24小时后，由于肿瘤供血血管突然关闭，DCE-MRI得出的最大上升斜率（MSI）和正性增强积分（PEI）急剧下降。肿瘤周边的DWI得出的表观扩散系数（ADC）因缺血性细胞水肿而降低。在第4天，MSI的增加可能是由于血供恢复所致。ADC的显著增加表明肿瘤内出现了大面积坏死。在第8天，血液灌注进一步下降，坏死范围进一步扩大，表现为较低的MSI和PEI值以及较高的ADC值。在第12天，由于周边肿瘤的再生长，ADC出现了第二次下降。实验数据表明，VDT的治疗效果可以通过DCE-MRI（反映肿瘤血液灌注）和DWI（反映组织学变化）进行无创监测，这为评估抗癌治疗提供了有力手段。
