NTCT-01RADIATION NECROSIS IN GLIOBLASTOMA PATIENTS: THE IMPACT OF EXTENT OF RESECTION

Abstract

NEUROTOXICITY OF CANCER TREATMENT (EFFECTS ON CNS, PNS; PRECLINICAL AND CLINICAL/HUMAN STUDIES) NTCT-01. RADIATION NECROSIS IN GLIOBLASTOMA PATIENTS: THE IMPACT OF EXTENT OF RESECTION JongHee Chang, Hun Ho Park,TaeHoon Roh,EuiHyun Kim, Seok Gu Kang, Se Hoon Kim, Sung Soo Ahn, Jaeho Cho, and Chang-Ok Suh; Yonsei University Health System, Seoul, Republic of Korea BACKGROUND: Radiation necrosis (RN) is a radiation-induced toxicity that has substantial neurological consequence in glioblastoma (GBM) patients. MGMT promoter methylation has been shown to be an important prognostic factor of RN, but the significance of extent of resection (EOR) remains unclear. METHODS: A retrospective analysis was done on newly diagnosed GBM patients with assessable MGMT promoter status who underwent Stupp protocol. EOR was grouped into grossly total resection (GTR), subtotal resection (STR), partial resection (PR) and stereotactic biopsy. Contrast enhancing lesion enlargement was classified as RN or non-RN. RESULTS: 101 patients received GTR, STR, PR and stereotactic biopsy in 57 (56.4%), 34 (33.7%), 9 (8.9%) and 1 patients (1%), respectively. Follow-up imaging done at the end of Stupp protocol was classified 45 patients (44.6%) as RN and 58 patients (55.4%) as non-RN. RN was observed in 24 (61.5%) of 39 methylated MGMT promoter and 21 (33.9%) of 62 unmethylated MGMT promoter patients (p , 0.01). RN was documented in 17 (29.8%), 19 (55.9%), 8 (88.9%) and 1 (100%) patients when EOR was grouped into GTR, STR, PR and stereotactic biopsy (p , 0.01), respectively. On multivariate analysis MGMT promoter status (OR 3.51, 95% CI 1.39-8.87) andEOR(OR 3.30,95% CI1.28-8.49)became independent predictors of RN. A Cox proportional hazards model showed MGMT status (HR 2.51, p , 0.01) and EOR (HR 2.99, p , 0.01) significantly influenced survival. Conclusions: The predictive value of MGMT status and EOR can help understand RN in equivocal situations. GTR can reduce RN and prolong survival. Neuro-Oncology 17:v172–v175, 2015. doi:10.1093/neuonc/nov226.1 Published by Oxford University Press on behalf of the Society for Neuro-Oncology 2015.