Prognostic Importance of SUV-max Values Evaluated by 18F-FDG-PET/CT Before Nivolumab Treatment in Patients with Metastatic Renal Cell Carcinoma.

BACKGROUND Nivolumab is a monoclonal antibody that binds to the programmed death-1 (PD-1) receptor and blocks its interaction with PD-L1 and PD-L2. High response rates have been achieved with its use in the treatment of metastatic renal cell carcinoma (mRCC). We aimed to determine a relationship between 18-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography (18F-FDG-PET/CT) performed before nivolumab treatment and treatment-related survival. METHODS Between 2014 and 2021, 32 patients who received nivolumab and had pretreatment 18F-FDG-PET/CT evaluation were included in this retrospective study. The total SUVmax (sum of SUVmax) of all tumoral foci and the lesion with the highest SUVmax value were recorded. The relationship of these values with progression-free survival (PFS) and overall survival (OS) was evaluated. RESULTS The median highest SUVmax and sum of SUVmax values were found as 14.4 and 41.4, respectively. PFS and OS were longer in the group with a sum of SUVmax value below 41.4 compared to the group with a higher group (OS, median 9.52 vs. 4.2 months (p=0.018); PFS, median 9.6 vs. 3 months(p=0.003), respectively). In the group with the highest suv-max value below 14.4, PFS was evaluated as statistically significant compared to the higher group (PFS, median 16.74 vs. 3.3 months(p=0.004)), while OS was not found to be statistically significant (OS, median 25.45 vs. 16.74 months (p=0.110)). CONCLUSIONS Our study showed that there might be a relationship between SUVmax values and PFS and OS. The SUVmax values before nivolumab treatment can be used to predict prognosis and survival in mRCC patients.