Use of pretreatment metabolic tumor volumes on PET-CT to predict the survival of patients with squamous cell carcinoma of esophagus treated by curative surgery.

Aim: To investigate the prognostic role of the pretreatment metabolic tumor volume (MTV) as determined by Positron emission tomography--computed tomography (PET-CT) in patients with esophageal cancer undergoing curative surgery.

Patients And Methods: We retrospectively reviewed the data of 26 patients with squamous cell carcinoma of the esophagus, who underwent 18F-Fluorodeoxyglucose PET-CT before surgery. MTVs were defined as the volumes with FDG uptake above a standardized uptake value (SUV) of 2.5 (MTV2.5), or a fixed threshold of 20% (MTV20%) of the maximum intratumoral activity. Overall survival (OS) and disease-free survival (DFS) were examined by the Kaplan-Meier method and the log-rank test.

Results: In a median follow-up of 15 months, 13 patients had died. The mean MTV2.5 was 18.9 ± 15.4 ml (median, 16.0), whereas the mean MTV20% was 21.7 ± 15.0 ml (median, 19.1). Patients who had tumors of an MTV2.5 >16.0 ml had an inferior one-year OS compared with patients with a lower MTV2.5 (70% vs. 84%, p=0.018). Similarly, patients with an MTV20% >19.1 ml had poorer outcomes compared with patients who had small tumors, with one-year OS of 69% and 85%, respectively (p=0.016). No statistical significance was found in DFS for both MTV approaches. The SUVp-max had no impact on the OS and the DFS when using a median value of 8.3.

Conclusion: Pretreatment MTV is a novel marker for OS of patients with esophageal cancer treated with curative surgery. For those with higher MTVs, more aggressive adjuvant treatments should be considered.