605 Background: We previously reported that the early assessment by FDG-PET/CT of patients with advanced renal cell carcinoma (aRCC) treated with tyrosine kinase inhibitors (TKIs) predicted the disease course. In this study, we investigated prospectively the relationship of the clinical outcome of patients with aRCC treated with sorafenib and radiological parameters obtained with FDG-PET/CT at baseline and 4 weeks (4W). Methods: The patients with TKI-naïve aRCC planning to be treated by sorafenib were enrolled and assessed by FDG-PET/CT at baseline and at 4W. The relationship between radiological parameters, (1) max SUVmax at baseline, (2) change in max SUVmax at 4week, and (3) response criteria defined by Ueno D et al. ( The prognosis of aRCC which max SUVmax decreased more or 20% at 4W demonstrated good prognosis. BMC Cancer 2012) and progression-free survival (PFS) and overall survival (OS) was exploratory evaluated. This study is multicenter-study using PET/CT systems which quality is ensured by previous phantom study. Results: Total 34 patients were enrolled. The median PFS were 9.7 months and mean OS were 35.8 months (survival curve did not reach 0.5). The median of max SUVmax (the highest standardized uptake value in each patients) at baseline was 5.1. The median PFS of patients with baseline max SUVmax ≤ 5.1 showed longer PFS and OS compared that with max SUVmax > 5.1 (median PFS 11.9months vs. 9.2 month P= 0.0354, median OS --- vs. 15.3 months P= 0.027 ). The median change ratio in max SUVmax at 4W was -9.5%. The change ratio did not affect the PFS and OS, analyzing the total patients. When the patients with max SUVmax > 4.0 at baseline were focused, the PFS of patients which max SUVmax decreased more or 20% at 4W demonstrated tendency to be longer than that of other patients (median PFS 15.6 months vs 9.2 months, P= 0.0727) Conclusions: In this study, we demonstrated that the pretreatment max SUVmax predicted the PFS and OS of aRCC treated by sorafenib, but change of max SUV max at 4W did not. The change ratio could have potency as a predict marker for the PFS in the cases with high max SUVmax at baseline. It was speculated that the accurate assessment of change ratio in the cases with low max SUVmax at baseline was difficult. Clinical trial information: 000009812.
Can Initial 18F-FDG PET-CT Imaging Give Information on Metastasis in Patients with Primary Renal Cell Carcinoma?