Abstract
1426
Objectives We evaluated a prognostic value of PET/CT using quantitative parameters of maximal standardized uptake value (SUVmax) and a volume-based parameter of total lesion glycolysis (TLG) in advanced RCC treated with targeted therapy agents.
Methods 38 patients with advanced RCC who underwent FDG PET/CT and were treated with targeted therapy agents were retrospectively enrolled. SUVmax of lesions were measured, and TLG was calculated as a product of tumor volume and mean SUV. An overall TLG was calculated as the sum of those of all lesions. The prognostic value of PET parameters, and clinical factors (serum hemoglobin and corrected calcium) were tested with Kaplan-Meier methods. Multivariate analyses were performed using Cox proportional regression models.
Results Among 38 patients, 9 died during mean follow-up time of 15.7 ± 13.2 (range 0.9-63.4) months. On FDG PET/CT, a total of 262 lesions were analyzed. In univariate analyses, SUVmax (P = 0.0013), TLG (P = 0.0001), serum hemoglobin (P = 0.0002) and corrected calcium (P = 0.0126) were significant prognostic factors. Among them, TLG remained as an independent prognostic factor in a multivariate analysis. A subgroup analysis was performed in the patients who were treated with a single targeted therapy agent of sunitinib. In this subgroup, SUVmax (P =0.019), TLG (P = 0.001), and serum hemoglobin (P = 0.012) were also significant prognostic factors, among which TLG was the only significant prognostic factor.
Conclusions FDG PET/CT has a significant prognostic values for survival in RCC, with parameters of SUVmax and TLG. Particularly, TLG has a greater prognostic value than SUVmax. With addition of TLG to established clinical prognostic factors, more appropriate prediction of prognosis would be available