NIMG-77. RESPONSE ASSESSMENT USING MULTIPARAMETRIC MRI DURING CHEMORADIATION PREDICTS OVERALL SURVIVAL IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA. (11th November 2019)

• Record Type: Journal Article
• Authors: Kim, Michelle; Aryal, Madhava; Parmar, Hemant; Li, Pin; Schipper, Matthew; Wahl, Daniel; Lawrence, Theodore; Cao, Yue
• Is Part Of: Neuro-oncology. Volume 21(2019)Supplement 6
• Page Start: vi179
• Page End: vi179
• Publication Date: 2019-11-11
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noz175.746
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: INTRODUCTION: Identifying both aggressive hypercellular (HCV) and hyperperfused (hCBV) regions of glioblastoma (GBM) prior to radiation (RT) using multiparametric MRI (mpMRI) predicts PFS and recurrence better than either technique alone, and is under investigation in a phase II trial as a novel target for dose-intensified RT. We hypothesized that early response in combined HCV/hCBV could be assessed using mpMRI and predict OS better than baseline assessment. METHODS: Forty-three patients with newly diagnosed GBM underwent prospective high b-value (b=3000 s/mm2) DW-MRI and DCE-MRI pre-RT and 3 weeks into RT. Twenty patients were treated on a dose-escalation trial specifically targeting HCV/hCBV identified by mpMRI. An automated threshold method was used to generate HCV (mean contralateral normal brain+2SD) and hCBV (contralateral normal frontal grey matter+1SD). Survival was calculated using Kaplan-Meier method and compared using log-rank test. Age, gender, performance status, RT dose, extent of surgery, MGMT methylation, and imaging characteristic were tested in Cox proportional hazards models for survival. RESULTS: Most patients had gross total (47%) or subtotal resection (37%), and 25% were MGMT methylated. Significant volumetric reduction during RT was observed in the Gd-enhanced volume (4.4 cc reduction, 95%CI 1.1–7.7, 17%), as well as HCV (1.8 cc reduction, 95%CI 0.2–3.4, 19%) and hCBV (1.1 cc reduction, 95%CI -0.4–2.6, 10%). No difference was observed between MGMT subgroups, but patients treated on protocol specifically targeting the mpMRI volume had significant reduction in combined HCV/hCBV (-4.4 cc, 95%CI -6.6, -2.3) vs non-protocol patients (-0.3 cc, 95%CI -2.6, 2.0, p=0.006). A reduction in combined HCV/hCBV was associated with superior OS (AHR 0.60, 95%CI 0.40–0.89, p=0.01), while baseline imaging (all p< 0.90) and change in Gd-enhanced volume (p=0.61) were not. CONCLUSIONS: Significant early response in HCV/hCBV during treatment is observed when targeted with dose-intensified RT, and is associated with improved OS with potential for adaptive strategies in future trials.