Prognostic significance of metabolic parameters from l-methyl-11C-methionine PET/computed tomography before postoperative adjuvant therapy in patients with glioma

BACKGROUND: Gliomas remain challenging because of their heterogeneity and poor prognosis. This study evaluated the prognostic value of metabolic parameters derived from L-methyl- 11 C-methionine ( 11 C-MET) PET/computed tomography (CT) performed before adjuvant therapy in glioma patients. METHODS: A retrospective analysis was conducted on 22 postoperative glioma patients who underwent 11 C-MET PET/CT before initiating adjuvant therapy. Metabolic parameters, including maximum standardized uptake value (SUV max ), mean standardized uptake value (SUV mean ), metabolic tumor volume (MTV), total lesion glycolysis (TLG), maximum tumor-to-brain ratio (TBR max ), and mean tumor-to-brain ratio (TBR mean ) were extracted, calculated, and analyzed. Receiver operating characteristic analyses were performed to determine optimal cut-off values for predicting progression-free survival (PFS). Kaplan-Meier and log-rank tests were used to evaluate the relationship between metabolic parameters and PFS. RESULTS: All six parameters significantly predicted PFS. Optimal thresholds were SUV max (3.03), area under the curve (AUC): 0.884, SUV mean (2.84), AUC: 0.942, MTV (0.641, AUC: 0.880), TLG (2.140, AUC: 0.860), TBR max (4.64, AUC: 0.760), and TBR mean (4.50, AUC: 0.851). Patients above these cutoffs had shorter PFS (all P < 0.05). In the high-uptake groups (defined by thresholds: SUV max > 3.03, SUV mean > 2.84, MTV > 0.641, TLG > 2.140, TBR max > 4.64), the median overall survival times ranged from 263 to 279 days. In contrast, the low-uptake groups exhibited significantly longer median survival, ranging from 361 to 512 days. CONCLUSION: Preadjuvant 11 C-MET PET/CT provides valuable prognostic information in postoperative glioma patients. Incorporating 11 C-MET PET parameters into postoperative risk stratification may guide individualized treatment strategies and optimize clinical outcomes.