Apparent Diffusion Coefficient Metrics to Differentiate between Treatment-Related Abnormalities and Tumor Progression in Post-Treatment Glioblastoma Patients: A Retrospective Study.

Distinguishing treatment-related abnormalities (TRA) from tumor progression (TP) in glioblastoma patients is a diagnostic imaging challenge due to the identical morphology of conventional MR imaging sequences. Diffusion-weighted imaging (DWI) and its derived images of the apparent diffusion coefficient (ADC) have been suggested as diagnostic tools for this problem. The aim of this study is to determine the diagnostic accuracy of different cut-off values of the ADC to differentiate between TP and TRA. In total, 76 post-treatment glioblastoma patients with new contrast-enhancing lesions were selected. Lesions were segmented using a T1-weighted, contrast-enhanced scan. The mean ADC values of the segmentations were compared between TRA and TP groups. Diagnostic accuracy was compared by use of the area under the curve (AUC) and the derived sensitivity and specificity values from cutoff points. Although ADC values in TP (mean = 1.32 × 10-3 mm2/s; SD = 0.31 × 10-3 mm2/s) were significantly different compared to TRA (mean = 1.53 × 10-3 mm2/s; SD = 0.28 × 10-3 mm2/s) (p = 0.003), considerable overlap in their distributions exists. The AUC of ADC values to distinguish TP from TRA was 0.71, with a sensitivity and specificity of 65% and 70%, respectively, at an ADC value of 1.47 × 10-3 mm2/s. These findings therefore indicate that ADC maps should not be used in discerning between TP and TRA at a certain timepoint without information on temporal evolution.

Health-related quality of life and cognitive functioning in long-term anaplastic oligodendroglioma and oligoastrocytoma survivors.

Overall survival of patients with anaplastic oligodendroglial tumors has been improved due to the addition of procarbazine, lomustine and vincristine (PCV) chemotherapy to radiotherapy (RT), especially in 1p/19q-codeleted tumors. With improved survival, quality of survival becomes pivotal. We evaluated cognitive functioning and health-related quality of life (HRQOL) in a cohort of long-term anaplastic oligodendroglioma survivors. Thirty-two out of 37 long-term survivors included in European Organisation for Research and Treatment of Cancer (EORTC) study 26951 in the Netherlands and France participated. Cognition was assessed using neuropsychological tests for 6 domains, and HRQOL with the EORTC Quality of Life Questionnaire (EORTC QLQ-C30) and Brain Cancer Module (EORTC QLQ-BN20). Fatigue and mood were evaluated. Results were compared to healthy controls and to patients' own HRQOL 2.5 years following initial treatment. At the time of assessment, median survival for the patients was 147 months, 27 were still progression-free since initial treatment. Of progression-free patients, 26% were not, and 30% were severely cognitively impaired; 41% were employed and 81% could live independently. Patients' HRQOL was worse compared to controls, but similar to 2.5 years after initial treatment. Initial treatment (RT versus RT + PCV) was not correlated with cognition or HRQOL. In conclusion, cognitive functioning in long-term anaplastic oligodendroglioma survivors is variable. However, most patients function independently. In progression-free patients, HRQOL is relatively stable during the disease course. In this small sample, no effect of the addition of PCV on cognition or HRQOL was identified.