n.36 – PROGNOSTIC SIGNIFICANCE OF PET/CT TOTAL LESION GLYCOLYSIS IN PATIENTS WITH LOCALLY ADVANCED OESOPHAGEAL CANCER UNDERGOING NEOADJUVANT CHEMORADIOTHERAPY



Abstract

BACKGROUND-AIM
The aim of this study was to investigate the predictive prognostic value of tumor metabolic activity measurements on serial 2-deoxy-2-[F] fluoroD-glucose (18F-FDG) positron emission tomography (PET/CT) scans to assess neoadjuvant chemoradiotherapy response in patients with locally advanced oesophageal cancer.
METHODS
Forty five patients (63±7 yrs, 6 female) with advanced oesophageal cancer treated before surgery with concomitant chemoradiotherapy between 2006 and 2013 were followed-up for 24 ± 18 months (range 4-66). 18F-FDG PET/CT scans were obtained within one week before the start (PET1) and 1 month after the completion of the treatment (PET2). Tumour metabolitc activity was delineated measuring on the 18F-FDG scans the parameters: maximum standardized uptake value (SUVmax), SUV corrected for lean body mass (SUL) and total lesion glycolysis (TLG = total volume × SUVmean). Then,  values for the parameters between PET1 and PET2 were calculated and expressed as % of PET1 measures.
RESULTS
At the moment of the analysis 25 patients were dead (Group1) and 20 alive (Group2). At univariate analysis of the PET/CT parameters, TLG at the end of the treatment, SUVmax, SUL and TLG resulted predictive of patients survival. At multivariate analysis, only TLG at the end of the treatment and TLG were significantly and independently associated with survival. ROC curve analysis showed a cut-off of 79498 for TLG as the optimal criterion to discriminate between Group1 and Group2 patients (AUC 0.81). ROC curves analysis resulted in -80% cut-off for TLG as the best to discriminate Group1 and Group2 patients (AUC 0.83). Using these cut-offs, log-rank analysis of the Kaplan–Meier method and Cox’s proportional hazards method confirmed the ability of TLG at the end of treatment [hazard ratio (HR), 0.30; 95% (CI), 0.13-0.66; P<0.005] and TLG [HR 0.39; 95% (CI), 0.17-0.87; P<0.04] to predict patients survival.
CONCLUSION
TLG is a promising predictive factor of outcome in patients with locally advanced oesophageal cancer undergoing neoadjuvant chemoradiotherapy with statistically higher prognostic power than other semiquantitative measures obtained in 18F-FDG scans.

Scarica PDF