Ogiwara Hideki, Tsutsumi Yoshiyuki, Matsuoka Kentarou, Kiyotani Chikako, Terashima Keita, Morota Nobuhito
Division of Neurosurgery, National Center for Child Health and Development, Okura 2-10-1, Setagaya-ku, Tokyo, 157-8535, Japan,
J Neurooncol. 2015 Feb;121(3):565-71. doi: 10.1007/s11060-014-1668-y. Epub 2014 Nov 21.
The role of diffusion weighted imaging and apparent diffusion coefficient in intracranial germ cell tumors has not been fully elucidated. The aim of this study was to evaluate whether the ADC correlates with the histologic subtypes of germ cell tumors. We also aimed to investigate whether the ADC values can predict treatment response. The authors retrospectively analyzed the ADC values of the enhancing and solid regions of germ cell tumors. The absolute ADC values and the normalized ADC values were compared among different histologic diagnoses. The ADC values before and after the first course of chemotherapy were also compared between the different prognostic groups. Ten patients were included in the study. The median age at diagnosis was 9.3 years (range 5.3-13.8 years). There were four patients with germinoma and six patients with nongerminomatous germ cell tumor (NGGCT) including five mixed germ cell tumors and one immature teratoma. The mean absolute and normalized ADC values (×10(-3) mm(2)/s) were significantly lower in germinomas [0.835 ± 0.065 (standard deviation) and 1.11 ± 0.096, respectively] than in NGGCTs (1.271 ± 0.145 and 1.703 ± 0.223, respectively) (p = 0.01). The ADC values before and after the first course of chemotherapy were available in four patients. The ADC value after the first chemotherapy had a tendency to increase more in patients who eventually demonstrated complete response with chemotherapy than in patients who required second-look surgery. Assessment of the ADC values of germ cell tumors is considered to facilitate differentiation of histological subtypes of germ cell tumors. Evaluation of the ADC may also be useful for predicting treatment response.
弥散加权成像及表观扩散系数在颅内生殖细胞肿瘤中的作用尚未完全阐明。本研究旨在评估表观扩散系数（ADC）是否与生殖细胞肿瘤的组织学亚型相关。我们还旨在研究ADC值是否能够预测治疗反应。作者回顾性分析了生殖细胞肿瘤强化及实性区域的ADC值。比较了不同组织学诊断之间的绝对ADC值和标准化ADC值。还比较了不同预后组在首个化疗疗程前后的ADC值。本研究纳入了10例患者。诊断时的中位年龄为9.3岁（范围5.3 - 13.8岁）。其中有4例生殖细胞瘤患者，6例非生殖细胞性生殖细胞肿瘤（NGGCT）患者，包括5例混合性生殖细胞肿瘤和1例未成熟畸胎瘤。生殖细胞瘤的平均绝对ADC值和标准化ADC值（×10(-3) mm(2)/s）[分别为0.835 ± 0.065（标准差）和1.11 ± 0.096]显著低于NGGCT（分别为1.271 ± 0.145和1.703 ± 0.223）（p = 0.01）。4例患者有首个化疗疗程前后的ADC值。与需要二次手术的患者相比，最终化疗显示完全缓解的患者在首个化疗后的ADC值有更大的升高趋势。评估生殖细胞肿瘤的ADC值被认为有助于区分生殖细胞肿瘤的组织学亚型。评估ADC值也可能有助于预测治疗反应。
