Prognostic significance of basal 18F-FDG PET / CT maximum standardized uptake value in patients with metastatic renal cell carcinoma who were treated with sunitinib.

Purpose: To determine whether there is a relationship between maximum standardized uptake (SUVmax) value of basal 18-Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) that was performed before sunitinib treatment and treatment-related survival in patients with metastatic renal cell carcinoma (mRCC).

Methods: The data of 36 patients (female/male: 1/1, median age 57.36 years, range 31-74) were retrospectively analyzed in whom sunitinib treatment was started due to mRCC between 2008 and 2019 and who underwent basal 18F-FDG PET/CT examination before this treatment. The median SUVmax value was 6.8. Progression-free survival (PFS) and overall survival (OS) rates of patients, who had SUVmax value >6.8 (group I) (50%, n=18) and ≤ than 6.8 (group II) (50%, n=18), were compared.

Results: Both PFS and OS were significantly lower in the group with high SUVmax (SUVmax> 6.8, group I) before the sunitinib treatment than the group with low SUVmax (SUVmax ≤6.8, group II). When patients with SUVmax value> 6.8 (group I) (50%, n=18) and ≤6.8 (group II) (50%, n=18) were compared the median PFS of group I patients was 6.83 months (95%CI: 6.14-7.52), while the median PFS of group II patients was 11.24 months (95%CI: 8.4-14.06) (p=0.035). The median OS in group I and II was 12.91 months (95%CI: 10.17-15.65) and 54.54 months (95%CI: 8.51-100), respectively (p=0.042).

Conclusion: In this study it was found that PFS and OS were low in patients with high SUVmax value in 18F-FDG PET/CT performed before sunitinib treatment. As a result, 18F-FDG PET/CT SUVmax values measured before sunitinib treatment can be used to predict survival in mRCC patients.