Objectives: Glioblastomas (GBM) are the most common primary invasive neoplasms of the brain. Distinguishing between lesion recurrence and different types of treatment related changes in patients with GBM remains challenging using conventional MRI imaging techniques. Therefore, accurate and precise differentiation between true progression or pseudoresponse is crucial in deciding on the appropriate course of treatment. This retrospective study investigated the potential of apparent diffusion coefficient (ADC) map values derived from diffusion-weighted imaging (DWI) as a noninvasive method to increase diagnostic accuracy in treatment response. Methods: A cohort of 21 glioblastoma patients (mean age: 59.2 ± 11.8, 12 Male, 9 Female) that underwent treatment with bevacizumab were selected. The ADC values were calculated from the DWI images obtained from a standardized brain protocol across 1.5-T and 3-T MRI scanners. Ratios were calculated for rADC values. Lesions were classified as bevacizumab-induced cytotoxicity based on characteristic imaging features (well-defined regions of restricted diffusion with persistent diffusion restriction over the course of weeks without tissue volume loss and absence of contrast enhancement). The rADC value was compared to these values in radiation necrosis and recurrent lesions, which were concluded in our prior study. The nonparametric Wilcoxon signed rank test withp< 0.05 was used for significance. Results: The mean ± SD age of the selected patients was 59.2 ± 11.8. ADC values and corresponding mean rADC values for bevacizumab-induced cytotoxicity were 248.1 ± 67.2 and 0.39 ± 0.10, respectively. These results were compared to the ADC values and corresponding mean rADC values of tumor progression and radiation necrosis. Significant differences between rADC values were observed in all three groups (p< 0.001). Bevacizumab-induced cytotoxicity had statistically significant lower ADC values compared to both tumor recurrence and radiation necrosis. Conclusion: The study demonstrates the potential of ADC values as noninvasive imaging biomarkers for differentiating recurrent glioblastoma from radiation necrosis and bevacizumab-induced cytotoxicity.
目的：胶质母细胞瘤（GBM）是最常见的原发性侵袭性脑肿瘤。在GBM患者中，利用常规磁共振成像技术区分病灶复发与不同类型的治疗相关改变仍具挑战性。因此，准确鉴别真实进展与假性反应对于制定恰当治疗方案至关重要。本回顾性研究探讨了基于扩散加权成像（DWI）的表观扩散系数（ADC）图值作为无创性方法提升治疗反应诊断准确性的潜力。方法：选取21例接受贝伐珠单抗治疗的胶质母细胞瘤患者（平均年龄：59.2±11.8岁，男性12例，女性9例）。ADC值通过1.5T和3T磁共振扫描仪的标准脑部协议获取的DWI图像计算得出，并计算相对ADC（rADC）比值。根据特征性影像表现（边界清晰的扩散受限区域，持续数周未见组织体积缩小且无对比增强），将病灶归类为贝伐珠单抗诱导的细胞毒性反应。将rADC值与既往研究中确定的放射性坏死及复发灶数值进行比较。采用非参数Wilcoxon符号秩检验（p<0.05）评估统计学显著性。结果：入选患者平均年龄为59.2±11.8岁。贝伐珠单抗诱导细胞毒性反应的ADC值及相应平均rADC值分别为248.1±67.2和0.39±0.10。这些结果与肿瘤进展和放射性坏死的ADC值及相应平均rADC值进行比较。三组间rADC值均存在显著差异（p<0.001）。贝伐珠单抗诱导细胞毒性反应的ADC值显著低于肿瘤复发和放射性坏死组。结论：本研究证实ADC值作为无创影像生物标志物在鉴别胶质母细胞瘤复发、放射性坏死及贝伐珠单抗诱导细胞毒性反应方面具有应用潜力。
肿瘤(癌症)患者之家