Prognostic value of pre-treatment 18F-FDG PET/CT volumetric parameters in patients with locally advanced larynx carcinoma.

Objectives the aim of this study was to assess the prognostic value of volumetric parameters measured on staging 18F-FDG PET/CT determining event free survival (EFS) and overall survival (OS) in patients with locally advanced larynx carcinoma treated with concurrent chemo-radiotherapy.

Methods we retrospectively analyzed 31 patients who performed a staging PET/CT for larynx carcinoma between 2008 and 2011. All patients had stage III-IV squamous cell carcinoma of the larynx treated with IMRT and concurrent chemotherapy. MTV, SUV max/mean and TLG were recorded. Univariate and multivariate analyses in association with Kaplan-Meier method were used to evaluate the prognostic value of these parameters considering EFS and OS.

Results In the univariate analysis, MTV (>20cm3) using a 2,5 SUV threshold had the best prognostic value than other PET/CT parameters. We found a significant difference for predicting EFS (p<0,0001) and OS (p>0,0001) between the high MTV 2.5 (>20 cm3) and low MTV 2.5 (&#8804; 20cm3). In multivariate analysis, MTV and visual interpretation of local invasion remained significantly associated with EFS and OS (p= 0.012) while SUV max and TLG became non-significant (p=0.4 for EFS and p=0.7 for OS). At median follow up of 40 months the relapse rate was 42% (13/31 pts)

Conclusions Our data suggest that the pre-treatment 18F-FDG PET/CT MTV (>20cm3) provide better prognostic information in patients with locally advanced larynx cancer than other PET/CT parameters. A 58% cure rate in this high risk population is encouraging and confirm that chemoradiation may be a therapeutic option.