Introduction/Background The Standardised Uptake Value (SUV) on FDG PET reflects glycolytic metabolism and high values have been shown to be associated with aggressive tumour biology and a poor prognosis in some but not all cancers. The purpose of this study was to evaluate the association of baseline SUVmax with tumour volume, lymph-node involvement and survival in loco-regionally advanced cervix cancer (LRACC) patients.

Methodology One hundred fifty-one LRACC patients, treated with curative intent between 1996 and 2014 were retrieved. Patients were classified to FIGO 2018 staging based on histopathology, MRI (for tumour volume and local compartmental spread) and PET (for measuring SUVmax and nodal spread). Association of SUVmax with known prognostic factors such as age, histology, FIGO stage, tumour volume and nodal spread was studied using relevant statistical tests and regression models. Cox proportional hazards model was used to evaluate predictors of relapse-free and overall survival.

Results SUVmax of the primary tumour was significantly higher (17.2 vs 13.8, p=0.012) in patients with positive nodes compared to those who were node negative. Similarly, SUVmax was 3.6 units higher in those with tumour volume above the median (34.3cc) compared to those with tumour volume below the median (p=0.007). There was no difference in the distribution of relapses and deaths by quartiles of SUVmax. There was no significant difference in FDG uptake by histology, p=0.2352. While node positivity and tumour volume were independent predictors of relapses, SUVmax was not. Tumour volume was an independent predictor of overall survival in LRACC.

Conclusion Prognosis in LRACC depends on the interplay between primary tumour (local control) and nodal disease (regional and distant relapse). SUVmax has limited independent prognostic value in LRACC. The primary role of FDG PET/CT remains detection of nodal and distant metastasis.