We have investigated the acute and sustained hemodynamic effects of octreotide on hepatic metastases of midgut carcinoids using contrast-enhanced dynamic magnetic resonance imaging (MRI). Seven patients with the carcinoid syndrome and metastasized midgut carcinoid tumors underwent functional dynamic multi-phase gadolinium-enhanced MRI of selected liver metastases at baseline and 60 min after the subcutaneous (s.c.) administration of 100 μg octreotide, and also after 3 months with three times daily (t.i.d.) 100 μg octreotide s.c. Baseline MRIs showed the typical aspect of carcinoid liver metastases with a very bright signal on the T2-weighted sequences and intense enhancement in the arterial phase after injection of gadolinium-diethylenetriamine-pentaacetate. MRIs 60 min after the s.c. administration of 100 μg octreotide showed a 34.9 ± 6.2% (mean ± SD) reduction in relative enhancement in the selected liver metastases as compared to baseline. In 2 patients, however, there was no (significant) reduction in the relative enhancement in the selected liver metastases 60 min after the s.c. administration of 100 μg octreotide as compared to baseline. Only in 2 patients did the MRIs at 3 months show a decrease in relative enhancement in one of the selected liver metastases. At 3 months, with 100 μg octreotide s.c. t.i.d., there was no correlation between the change in relative enhancement on MRI and the change in 24-hour 5-HIAA excretion. There is thus only an acute effect of octreotide on the perfusion of liver metastases. This study further shows that contrast-enhanced dynamic MRI can be a very useful tool for studying hemodynamic effects of medical therapies on liver metastases in patients with metastatic midgut carcinoids. Copyright

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Keywords Carcinoid syndrome, Clinical neuroendocrinology, Liver, Magnetic resonance imaging, Neuroendocrine tumors, Octreotide, Somatostatin analogs
Persistent URL dx.doi.org/10.1159/000090636, hdl.handle.net/1765/68104
Journal Neuroendocrinology: international journal for basic and clinical studies on neuroendocrine relationships
Citation
Zomerhuis, M.T, Hussain, S.M, Feelders, R.A, van der Lely, A-J, & de Herder, W.W. (2005). Octreotide exerts only acute, but no sustained, effects on MRI enhancement of liver metastases in carcinoid syndrome. Neuroendocrinology: international journal for basic and clinical studies on neuroendocrine relationships, 82(1), 41–48. doi:10.1159/000090636