# Prognostic Value of Pretreatment 18F-FDG-PET/CT Metabolic Parameters in Advanced High-Grade Serous Ovarian Cancer

## TL;DR

This study shows that pretreatment PET/CT metabolic parameters can predict relapse risk in advanced ovarian cancer patients.

## Contribution

The study identifies pretreatment metabolic tumor volume (MTV) as a strong predictor of relapse in high-grade serous ovarian cancer.

## Key findings

- High metabolic tumor volume (MTV) and total lesion glycolysis (TLG) are linked to shorter disease-free survival.
- Pretreatment MTVtotal is a statistically significant predictor of relapse in advanced HGSOC patients.
- No significant correlation was found between metabolic parameters and overall survival.

## Abstract

Patients with advanced high-grade serous ovarian cancer (HGSOC) have high relapse and mortality rates. The aim of our work was to assess the prognostic value of pretreatment 18F-FDG-PET/CT quantitative metabolic parameters in these patients. Our results show that pretreatment PET metabolic parameters can identify risk groups in advanced high-grade serous ovarian cancer. High metabolic tumor volume (MTV) and total lesion glycolysis (TLG) are associated with shorter disease-free survival (DFS), with MTV being the strongest predictor. Pretreatment MTV may be able to predict high risk of relapse in patients with advanced HGSOC at initial staging.

Aim: To assess the prognostic value of pretreatment 18F-FDG-PET/CT quantitative metabolic parameters in patients with advanced high-grade serous ovarian cancer (HGSOC). Methods: A review of 47 patients diagnosed with advanced HGSOC between 2012 and 2020 in our center was performed, evaluating pretreatment 18F-FDG-PET/CT metabolic parameters: maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG) and metabolic tumoral volume (MTV). Two experienced nuclear medicine physicians evaluated the images, thereby obtaining quantitative parameters semiautomatically classifying the volume of interest (VOI) as the target (t): VOI with the highest SUVmax normalized by lean body mass (SUVmax(lbm)), non target (nt) and total (sum of target and non-target VOIs). The disease-free survival (DFS) and overall survival (OS) were calculated. Optimal cutoff values with ROC curves/median values were used. The Correlation between metabolic parameters and DFS/OS was determined using univariate and survival-curves analysis. Results: The median DFS was 18 months (2.5–55) and the OS 33.6 months (2.5–92). The MTVtotal, MTV(t), TLGtotal and TLG(t) were significantly associated with DFS (p = 0.005, 0.01, 0.04 and 0.04, respectively). The patients with MTVtotal > 427.8 cm3 and MTVtarget > 434 cm3 had shorter DFS than the patients with lower values (18.8 versus 31 months and 15.6 versus 30, p = 0.02 and 0.01, respectively). The patients with higher TLGtotal and TLG(t) values tended to have worse DFS (p = 0.26 and 0.31, respectively). In a multivariate analysis, the MTVtotal was statistically significantly associated with DFS (p = 0.003). No correlation was found with OS. Conclusions: Pretreatment MTVtotal and MTV(t) appear to be predictive of relapse in patients with advanced HGSOC.