Hsu Christopher H, Lober Robert M, Li Matthew D, Partap Sonia, Murphy Patricia A, Barnes Patrick D, Fisher Paul G, Yeom Kristen W
Department of Oncology, Lucile Packard Children's Hospital, Stanford University, 750 Welch Rd Suite 317, Palo Alto, CA, 94304, USA.
J Neurooncol. 2015 May;122(3):491-6. doi: 10.1007/s11060-015-1754-9. Epub 2015 Mar 11.
Recent small, retrospective series suggest bevacizumab may be a therapeutic option for recurrent pediatric low-grade glioma (LGG). Assessment of therapeutic responses is complicated by the unpredictable natural history of these tumors. Because diffusion-weighted imaging quantifies microscopic water motion affected by cellular density and histologic features, we hypothesized that it may be helpful in monitoring therapeutic response of LGG to bevacizumab. We retrospectively reviewed eight consecutive patients, median age 4.8 (range 2.3-12.3) years at initiation of bevacizumab therapy for recurrent or refractory LGG. Patients received 10 mg/kg/dose every 2 weeks (median 16 doses/therapy course). Mean apparent diffusion coefficient (ADC) was measured and analyzed in respect to tumor volume. Following the first treatment course, seven of eight patients had reduced tumor volume (≥25 %) and ADC. The median decrease in tumor volume was 47% (range -6 to 78 %) and the median decrease in ADC was 14 % (range -5 to 30 %). The ADC was significantly decreased during therapy, whereas the decrease in volume was seen only after therapy completion. There was a positive correlation between percent change in tumor volume and ADC (p < 0.05). We report a decrease in tumor ADC during initial bevacizumab therapy that is accompanied by a decrease in volume following therapy. Imaging changes in microscopic water motion associated with histology may be useful in monitoring the therapeutic response of LGG to bevacizumab.
近期的小型回顾性系列研究表明，贝伐单抗可能是复发性儿童低级别胶质瘤（LGG）的一种治疗选择。这些肿瘤不可预测的自然病程使得治疗反应的评估变得复杂。由于扩散加权成像可量化受细胞密度和组织学特征影响的微观水分子运动，我们推测其可能有助于监测LGG对贝伐单抗的治疗反应。我们回顾性分析了8例连续的复发性或难治性LGG患者，他们在开始接受贝伐单抗治疗时的中位年龄为4.8岁（范围2.3 - 12.3岁）。患者每2周接受10 mg/kg剂量的治疗（中位每疗程16剂）。测量并分析了平均表观扩散系数（ADC）与肿瘤体积的关系。在第一个疗程后，8例患者中有7例肿瘤体积（≥25%）和ADC降低。肿瘤体积的中位减少率为47%（范围 - 6至78%），ADC的中位减少率为14%（范围 - 5至30%）。治疗期间ADC显著降低，而体积减少仅在治疗完成后出现。肿瘤体积变化百分比与ADC之间存在正相关（p < 0.05）。我们报告在初始贝伐单抗治疗期间肿瘤ADC降低，且治疗后体积随之减少。与组织学相关的微观水分子运动的影像学变化可能有助于监测LGG对贝伐单抗的治疗反应。
