Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, 676 N St. Clair St, Ste 1820, Chicago, IL, 60611, USA.
Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
J Neurooncol. 2022 Jul;158(3):331-339. doi: 10.1007/s11060-022-04018-3. Epub 2022 May 7.
We investigated the prognostic significance of tumor-associated white matter (TA-WM) tracts in glioblastoma (GBM) using magnetic resonance-diffusion tensor imaging (MR-DTI). We hypothesized that (1) TA-WM tracts harbor microscopic disease not targeted through surgery or radiotherapy (RT), and (2) the greater the extent of TA-WM involvement, the worse the survival outcomes.
We studied a retrospective cohort of 76 GBM patients. TA-WM tracts were identified by MR-DTI fractional anisotropy (FA) maps. For each patient, 22 TA-WM tracts were analyzed and each tract was graded 1-3 based on FA. A TA-WM score (TA-WMS) was computed based on number of involved tracts and corresponding FA grade of involvement. Kaplan-Meier statistics were utilized to determine survival outcomes, log-rank test was used to compare survival between groups, and Cox regression was utilized to determine prognostic variables.
For the MGMT-unmethylated cohort, there was a decrease in OS for increasing TA-WMS (median OS 16.5 months for TA-WMS 0-4; 13.6 months for TA-WMS 5-8; 7.3 months for TA-WMS > 9; p = 0.0002). This trend was not observed in the MGMT-methylated cohort. For MGMT-unmethylated patients with TA-WMS > 6 and involvement of tracts passing through brainstem or contralateral hemisphere, median OS was 8.3 months versus median OS 14.1 months with TA-WMS > 6 but not involving aforementioned critical tracts (p = 0.003 log-rank test). For MGMT-unmethylated patients, TA-WMS was predictive of overall survival in multivariate analysis (HR = 1.14, 95% CI 1.03-1.27, p = 0.012) while age, gender, and largest tumor dimension were non-significant.
Increased TA-WMS and involvement of critical tracts are associated with decreased overall survival in MGMT-unmethylated GBM.
我们通过磁共振弥散张量成像（MR-DTI）研究肿瘤相关白质（TA-WM）束在胶质母细胞瘤（GBM）中的预后意义。我们假设：（1）TA-WM 束包含未通过手术或放疗（RT）靶向的微观疾病；（2）TA-WM 受累程度越大，生存结局越差。
我们研究了 76 名 GBM 患者的回顾性队列。通过 MR-DTI 各向异性分数（FA）图识别 TA-WM 束。对每位患者的 22 条 TA-WM 束进行分析，并根据 FA 将每条束分为 1-3 级。根据受累束的数量和受累 FA 分级，计算 TA-WM 评分（TA-WMS）。Kaplan-Meier 统计用于确定生存结果，对数秩检验用于比较组间生存，Cox 回归用于确定预后变量。
对于 MGMT 未甲基化队列，TA-WMS 增加时 OS 降低（TA-WMS 0-4 为 16.5 个月；TA-WMS 5-8 为 13.6 个月；TA-WMS>9 为 7.3 个月；p=0.0002）。在 MGMT 甲基化队列中未观察到这种趋势。对于 TA-WMS>6 且受累束穿过脑干或对侧半球的 MGMT 未甲基化患者，中位 OS 为 8.3 个月，而 TA-WMS>6 但不累及上述关键束的中位 OS 为 14.1 个月（p=0.003 对数秩检验）。对于 MGMT 未甲基化患者，TA-WMS 在多变量分析中是总生存的预测因素（HR=1.14，95%CI 1.03-1.27，p=0.012），而年龄、性别和最大肿瘤尺寸无显著意义。
MGMT 未甲基化 GBM 中，TA-WMS 增加和关键束受累与总生存时间缩短相关。
