Dynamic Octreotide scintigraphy in neuroendocrine tumours

The purpose of the present study was to investigate the optimal time for scintigraphy after injection of the radio-labelled somatostatin analogue, Octreotide. A secondary purpose was to evaluate the value of SPECT. One SPECT study and up to 4 whole body scans were performed in 22 patients with neuroendocrine tumours 0.5, 5, 24 and 48 hours after an injection of 110 MBq In-DTPA Octreotide. A total of 98 scintigrams were studied. A pathological uptake was found in 19 of the 22 patients. In 3 cases, early scintigrams (0.5 and 5 hours after injection) were of the most value whereas late scintigrams (24 and 48 hours) were the best in 4 cases. SPECT was found to be of value in 13 of 21 cases. For correct interpretation of Octreotide scintigraphy it is necessary to obtain both early and late scintigrams as well as a SPECT study.