Large-volume low apparent diffusion coefficient lesions predict poor survival in bevacizumab-treated glioblastoma patients. Issue 5 (3rd November 2015)

• Record Type: Journal Article
• Authors: Zhang, Myron; Gulotta, Bryanna; Thomas, Alissa; Kaley, Thomas; Karimi, Sasan; Gavrilovic, Igor; Woo, Kaitlin M.; Zhang, Zhigang; Arevalo-Perez, Julio; Holodny, Andrei I.; Rosenblum, Marc; Young, Robert J.
• Is Part Of: Neuro-oncology. Volume 18:Issue 5(2016:May)
• Page Start: 735
• Page End: 743
• Publication Date: 2015-11-03
• Subjects: apparent diffusion coefficient -- (ADC) -- bevacizumab -- diffusion -- glioblastoma; Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/nov268
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: Background: Glioblastomas treated with bevacizumab may develop low-signal apparent diffusion coefficient (low-ADC) lesions, which may reflect increased tumor cellularity or atypical necrosis. The purpose of this study was to examine the relationship between low-ADC lesions and overall survival (OS). We hypothesized that growing low-ADC lesions would be associated with shorter OS. Methods: We retrospectively identified 52 patients treated with bevacizumab for the first ( n = 42, 81%) or later recurrence of primary glioblastoma, who had low-ADC lesions and 2 post-bevacizumab scans ≤90 days apart. Low-ADC lesion volumes were measured, and normalized 5th percentile histogram low-ADC values were recorded. Using OS as the primary endpoint, semiparametric Cox models were fitted to ascertain univariate and multivariate hazard ratios (HRs) with significance at P = .05. Results: Median OS was 9.1 months (95% CI = 7.2–14.3). At the second post-bevacizumab scan, the volume of the low-ADC lesion (median: 12.94 cm 3 ) was inversely associated with OS, with larger volumes predicting shorter OS (HR = 1.014 [95% CI = 1.003–1.025], P = .009). The percent change in low-ADC volume (median: 6.8%) trended toward increased risk of death with growing volumes ( P = .08). Normalized 5th percentile low-ADC value and its percent change were not associated with OS ( P > .51). Also correlated with shorter OS were the pre-bevacizumab nonenhancing volume ( P = .025), the first post-bevacizumab enhancing volume ( P = .040), and the second post-bevacizumab enhancing volume ( P = .004). Conclusions: The volume of low-ADC lesions at the second post-bevacizumab scan predicted shorter OS. This suggests that low-ADC lesions may be considered important imaging markers and included in treatment decision algorithms.