Pediatric Neurooncology Program, Department of Pediatric Oncology and Hematology, Charité-CVK, Berlin, Germany.
Department of Neurosurgery, University Hospital Würzburg, Würzburg, Germany.
Pediatr Blood Cancer. 2015 Jul;62(7):1252-8. doi: 10.1002/pbc.25485. Epub 2015 Apr 7.
Disease and therapy cause brain damage and subsequent functional loss in pediatric patients with posterior fossa tumors. Treatment-related toxicity factors are resection in patients with pilocytic astrocytoma (PA) and, additionally, cranio-spinal irradiation together with chemotherapy in patients with medulloblastoma (MB). We tested whether damage to white matter (WM) as revealed by diffusion tensor MR imaging (DTI) correlated with specific cognitive and motor impairments in survivors of pediatric posterior fossa tumors.
Eighteen MB (mean age ± SD, 15.2 ± 4.9 y) and 14 PA (12.6 ± 5.0 y) survivors were investigated with DTI on a 3-Tesla-MR system. We identified fractional anisotropy (FA) of WM, the volume ratio of WM to gray matter and cerebrospinal fluid (WM/GM + CSF), and volume of specific frontocerebellar tracts. Ataxia was assessed using the International Cooperative Ataxia Rating Scale (ICARS), while the Wechsler Intelligence Scale for Children determined full-scale intelligence quotients (FSIQ). Amsterdam Neuropsychological Tasks (ANT) was used to assess processing speed. Handwriting automation was analyzed using a digitizing graphic tablet.
The WM/GM + CSF ratio correlated significantly with cognitive measures (IQ, P = 0.002; ANT baseline speed, P = 0.04; ANT shifting attention, P = 0.004). FA of skeletonized tracts correlated significantly with FSIQ (P = 0.008), ANT baseline speed (P = 0.028) and ANT shifting attention (P = 0.045). Moreover, frontocerebellar tract volumes correlated with both the FSIQ (P = 0.011) and ICARS (P = 0.007).
DTI provides a method for quantification of WM damage by tumor and by therapy-associated effects in survivors of pediatric posterior fossa tumors. DTI-derived WM integrity may be a representative marker for cognitive and motor deterioration.
疾病和治疗会导致小儿后颅窝肿瘤患者的大脑受损和随后的功能丧失。在毛细胞型星形细胞瘤（PA）患者中，与治疗相关的毒性因素是切除术，而在髓母细胞瘤（MB）患者中，与治疗相关的毒性因素是颅脊髓照射联合化疗。我们测试了弥散张量磁共振成像（DTI）显示的白质（WM）损伤是否与小儿后颅窝肿瘤幸存者的特定认知和运动障碍有关。
对 18 例 MB（平均年龄±标准差，15.2±4.9 岁）和 14 例 PA（12.6±5.0 岁）幸存者进行了 3T-MR 系统上的 DTI 检查。我们确定了 WM 的各向异性分数（FA）、WM 与灰质和脑脊液的体积比（WM/GM+CSF）以及特定额-小脑束的体积。使用国际合作共济失调评定量表（ICARS）评估共济失调，而韦氏儿童智力量表则确定全量表智商（FSIQ）。阿姆斯特丹神经心理任务（ANT）用于评估处理速度。使用数字化图形平板电脑分析手写自动化。
WM/GM+CSF 比值与认知测量显著相关（智商，P=0.002；ANT 基线速度，P=0.04；ANT 转移注意力，P=0.004）。骨架化束的 FA 与 FSIQ 显著相关（P=0.008）、ANT 基线速度（P=0.028）和 ANT 转移注意力（P=0.045）。此外，额-小脑束体积与 FSIQ（P=0.011）和 ICARS（P=0.007）均相关。
DTI 提供了一种通过肿瘤和治疗相关效应定量评估小儿后颅窝肿瘤幸存者 WM 损伤的方法。DTI 衍生的 WM 完整性可能是认知和运动恶化的代表性标志物。
