Aim: The most common sites of metastasis in neuroendocrine tumors are liver, lymph nodes, and bone. The aim of this study is to determine the prevalence and location of other sites of metastasis.
Methods: 4,210 Ga-68 somatostatin-receptor PET/CT studies were performed at our center between July 2004 and December 2009. We retrospectively reviewed the reports of patients to check rare sites of metastasis other than liver, bone, and lymph nodes. Lesions were confirmed on follow-up and/or other imaging methods (MRI, echocardiography, and ultrasound).
Results: The different sites of metastasis according to frequency of occurrence were: cardiac (n = 29), breast (n = 21), retro-orbital (n = 9), uterus (n = 7), skin (n = 8), brain (n = 6), spleen (n = 3), testes (n = 1), seminal vesicle (n = 1), and intramuscular in psoas muscle (n = 4).
Conclusions: Cardiac and breast metastases appear to be not infrequent in neuroendocrine tumor patients. Ga-68 somatostatin-receptor PET/CT enables detection of these and other rare sites of metastasis.