Evaluation of the Effect of Pet/ct Fdg Inclusion on Mortality and Survival in Operated Thymoma Patients

Abstract Purpose: Thymic epithelial tumors (TET) constitute 50% of anterior mediastinal masses and are divided into three groups as thymoma, thymic carcinoma and neuroendocrine tumors. The most common TET is thymoma. In recent years, the use of Fuorodeoxyglucose Positron Emission Computed Tomography (PET-CT) has become widespread to evaluate the diagnosis, metabolism, stage and distant metastases of thymoma. In this study, it was aimed to investigate the connection of malignancy potential, survival and maximum standardized uptake value (SUVmax) measured by PET-CT before surgery according to the histological classification of the World Health Organization (WHO) in patients operated for thymoma. In addition, the predictive value of the Glasgow prognostic score (GPS) generated by C-Reactive Protein (CRP) and albumin values on recurrence and survival was investigated and its potential as a prognostic biomarker was evaluated. Materials & Methods: Forty-five patients who underwent surgical resection for thymoma and were examined with PET-CT in the preoperative period between January 2010 and January 2022 were included in the study. The relationship between WHO histological classification, tumor size and SUVmax values on PET-CT according to TNM classification of retrospectively analyzed patients’records were evaluated. Preoperative albumin and CRP values were used to determine GPS. Results: The cut-off value for SUVmax was found to be 5.65 in the patients and the overall survival rate of low-risk (<5.65) and high-risk (>5.65) patients was compared according to the SUVmax threshold value (5.65) and found to be statistically significant. In addition, the power of PET/CT SUVmax value to predict mortality (according to ROC analysis) was statistically significant (p=0.048). Survival expectancy was 127.6 months in patients with mild GPS (O points), 96.7 months in patients with moderate GPS (1 point), and 25.9 months in patients with severe GPS (2 points). Conclusions: PET/CT SUVmax values can be used to predict histological subtype in thymoma patients, and pre-operative SUVmax and GPS are parameters that can provide information about survival times and mortality in thymoma patients.