LAUSR

Objective The aim of this study is to evaluate the prognostic role of Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and quantitative 68Ga-DOTATATE PET/computed tomography parameters such as maximum standardized uptake value (SUVmax), mean SUV (SUVmean), DOTATATE tumor volume (DTV), total lesion DOTATATE (TLD) in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs) treated with 177Lu-DOTATATE. Material and method Our retrospective study included 21 patients with GEP-NETs treated with 177Lu-DOTATATE between January 2017 and January 2022. SUVmax, SUVmean, SUVmax/spleenSUVmax (SUVmax/Sx), DTV, TLD, SUVmean/spleenSUVmean (SUVmean/Sm), TLD/Sm values were calculated and recorded for all patients before and after 177Lu-DOTATATE treatment. Results A total of 319 metastases were detected in the patients included in the study, and a total of 68 target lesions were selected. In univariant Cox regression analysis, TLD/Sm percent change (∆TLD/Sm) was found to be statistically significant on overall survival (OS) (P = 0.044). The 3-year survival in nonresponders was 50% (P = 0.034) based on ∆SUVmax/Sx values, 50% (P = 0.002) based on RECIST values, 50% based on ∆TDTV + new lesion values (P = 0.033), and according to ∆TTLD + new lesion values, it was 66% (P = 0.030). Conclusion In our study, we showed that SUVmax/Sx, RECIST, ∆TDTV + new lesion, and ∆TTLD + new lesion parameters can predict OS in the evaluation of response to treatment.