Validation of Independent Prognostic Value of Asphericity of 18F-Fluorodeoxyglucose Uptake in Non-Small-Cell Lung Cancer Patients Undergoing Treatment With Curative Intent

A retrospective study was performed of 311 patients with non-small-cell lung cancer to investigate the prognostic value of asphericity (ASP), a parameter from pretherapeutic F-18-fluorodeoxyglucose positron emission tomography / computed tomography. Patients underwent treatment with curative intent. ASP showed prognostic value for progression-free and overall survival independent of established risk factors such as tumor stage or patient age. These results could help decide the intensity of treatment or follow-up. Background: In patients with non-small-cell lung cancer (NSCLC), asphericity (ASP) of the primary tumor's metabolic tumor volume (MTV) has shown prognostic significance. This study aimed at validation in an independent and sufficiently large cohort. Patients and Methods: A retrospective study was performed of 311 NSCLC patients undergoing F-18-fluorodeoxyglucose positron emission tomography / computed tomography (F-18-FDG PET/CT) before curatively intended treatment (always including surgery). A total of 140 patients had International Union Against Cancer (UICC) stage I disease, 78 had stage II disease, and 93 had stage III disease (adenocarcinoma, n = 153; squamous-cell carcinoma, n = 141). Primary tumor MTV was delineated with semiautomated background-adapted threshold relative to the standardized maximum uptake value (SUVmax). Cox regression (progression-free survival [PFS] and overall survival [OS]) analysis for positron emission tomography (MTV, ASP, SUVmax) as well as for clinical (T/N descriptor, UICC stages), histologic, and treatment variables (Rx/1 vs. RO resection, chemotherapy/radiotherapy yes/no) were performed. Results: Events (progression and relapse) occurred in 167 of 311 patients; 137 died (median survivor follow-up, 37 months). In multivariable Cox regression for OS, ASP > 33.3% (hazard ratio, 1.58 [1.04-2.39]), male sex (1.84), age (1.04 per year), Eastern Cooperative Oncology Group performance status >= 2 versus 0/1 (2.68), stage II versus I (1.96), and Rx/1 versus RO resection (2.1) were significant. Among separate UICC stages, ASP only predicted OS in stage II (optimal, > 19.5%; median OS, 33 vs. 59 months). Regarding PFS, ASP > 21.2%, male sex, Eastern Cooperative Oncology Group performance status >= 2, stage II versus I disease, and Rx/1 resection were prognostic. ASP remained prognostic for stage II disease (optimal, > 19.5%; PFS, 12 vs. 47 months). Log-rank test for ASP was significant at any cutoff >= 18% (OS) or from 9% to 59% (PFS). Conclusion: ASP was validated as prognostic factor for PFS and OS in patients with NSCLC and curative treatment intent, especially stage II. High ASP in stage II could imply intensified treatment or intensified follow-up. (C) 2019 Elsevier Inc. All rights reserved.