Sheth Rahul A, Feldman Adam S, Paul Elahna, Thiele Elizabeth A, Walker T Gregory
Rahul A Sheth, Department of Interventional Radiology, MD Anderson Cancer Center, Houston, TX 77030, United States.
World J Radiol. 2016 Mar 28;8(3):308-15. doi: 10.4329/wjr.v8.i3.308.
To investigate the angiographic and volumetric effects of mammalian target of rapamycin (mTOR) inhibitors on angiomyolipomas (AMLs) in a case series of patients with tuberous sclerosis complex.
All patients who underwent catheter angiography prior to and following mTOR inhibitor therapy (n = 3) were evaluated. All cross-sectional imaging studies were analyzed with three-dimensional volumetrics, and tumor volume curves for all three tissue compartments (soft tissue, vascular, and fat) were generated. Segmentation analysis tools were used to automatically create a region of interest (ROI) circumscribing the AML. On magnetic resonance images, the "fat only" map calculated from the in- and opposed-phase gradient recalled echo sequences was used to quantify fat volume within tumors. Tumor vascularity was measured by applying a thresholding tool within the ROI on post-contrast subtraction images. On computed tomography images, volume histogram analysis of Hounsfield unit was performed to quantify tumor tissue composition. The angiography procedures were also reviewed, and tumor vascularity based on pre-embolization angiography was characterized in a semi-quantitative manner.
Patient 1 presented at the age of 15 with a 6.8 cm right lower pole AML and a 4.0 cm right upper pole AML. Embolization was performed of both tumors, and after a few years of size control, the tumors began to grow, and the patient was initiated on mTOR inhibitor therapy. There was an immediate reduction in the size of both lesions. The patient then underwent repeat embolization and discontinuation of mTOR inhibition, after which point there was a substantial regrowth in both tumors across all tissue compartments. Patient 2 presented at the age of 18 with a right renal AML. Following a brief period of tumor reduction after embolization, she was initiated on mTOR inhibitor therapy, with successful reduction in tumor size across all tissue compartments. As with patient 1, however, there was immediate rebound growth following discontinuation of inhibitor therapy, without sustained control despite repeat embolization. patient 3 presented at the age of 5 with a left renal AML and underwent two embolization procedures without lasting effect prior to starting mTOR inhibition. As with patients 1 and 2, following discontinuation of therapy, there was immediate rebound growth of the tumor. Repeat embolization, however, was notable for a substantial reduction in intratumoral aneurysms and vascularity.
AML volume reduction as well as post-treatment rebound growth due to mTOR inhibitors involves all three tissue components of the tumor.
在一系列结节性硬化症患者中,研究雷帕霉素哺乳动物靶点(mTOR)抑制剂对肾血管平滑肌脂肪瘤(AML)的血管造影及体积方面的影响。
对所有在mTOR抑制剂治疗前后接受导管血管造影的患者(n = 3)进行评估。所有横断面成像研究均采用三维容积分析,并生成所有三个组织成分(软组织、血管和脂肪)的肿瘤体积曲线。使用分割分析工具自动创建一个围绕AML的感兴趣区域(ROI)。在磁共振图像上,利用同相和反相梯度回波序列计算出的“仅脂肪”图来量化肿瘤内的脂肪体积。通过在ROI内的对比剂后减影图像上应用阈值工具来测量肿瘤血管。在计算机断层扫描图像上,进行Hounsfield单位的体积直方图分析以量化肿瘤组织成分。还对血管造影程序进行了回顾,并以半定量方式描述基于栓塞前血管造影的肿瘤血管情况。
患者1在15岁时出现一个6.8 cm的右下极AML和一个4.0 cm的右上极AML。对两个肿瘤均进行了栓塞治疗,在数年的大小控制后,肿瘤开始生长,患者开始接受mTOR抑制剂治疗。两个病灶的大小立即减小。患者随后接受了重复栓塞并停用mTOR抑制剂,此后两个肿瘤在所有组织成分中均出现显著再生长。患者2在18岁时出现右肾AML。栓塞后肿瘤短暂缩小,随后开始接受mTOR抑制剂治疗,所有组织成分的肿瘤大小均成功减小。然而,与患者1一样,停用抑制剂治疗后立即出现反弹生长,尽管进行了重复栓塞仍未实现持续控制。患者3在5岁时出现左肾AML,在开始mTOR抑制治疗前接受了两次栓塞治疗,但均无持久效果。与患者1和2一样,治疗中断后,肿瘤立即出现反弹生长。然而,重复栓塞的显著之处在于肿瘤内动脉瘤和血管显著减少。
mTOR抑制剂导致的AML体积减小以及治疗后反弹生长涉及肿瘤的所有三个组织成分。