The quantification for the treatment response evaluation of Metastatic Gastroenteropancreatic Neuroendocrine Tumors in Ga-68 DOTATATE PET/CT

Aim: The treatment response evaluation by means of Ga-68 DOTATATE PET/CT in Metastatic Gastroenteropancreatic Neuroendocrine Tumors (GEPNET’s) needs careful attention due to the subtle changes that might affect decision. The aim of this study is to analyze a new modified method in quantification of the Ga-68 DOTATATE PET/CT in treatment response evaluation of GEP-NET’s.Materials and Methods: 37 patients with diagnosis of metastatik GEP-NET were included in the study. Comparative evaluation of Ga-68 DOTATATE PET/CT images before and after treatment were performed. Quantitative analysis as well as visual interpretation results were compared with oncology follow up. The patients were divided according to oncology follow up results as responders and nonresponders. Results: The comparative analysis results showed that the difference between mean SUVmax and index values after and before the treatment were not significant for primary lesions. However both the index values were significantly different between groups in metastatic lesions. Conclusion: The SUVmax levels of the metastatic lesions could be considered for determination of treatment response and quantification for the treatment response might be indicated in special cases.