Response to treatment with yttrium 90-DOTA-lanreotide of a patient with metastatic gastrinoma

1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)- lanreotide is a universal somatostatin (SST) receptor subtype ligand that binds to a large variety of human tumors. We report the case of a patient with metastatic gastrinoma who was treated with ⁹⁰Y-DOTA-lanreotide. Before treatment, dosimetry with ¹¹¹In-DOTA-lanreotide (150 MBq, 10 nmol) indicated a dose of 5.8 mGy/MBq for the recurrent abdominal gastrinoma, and a mean dose of ≃1.0 mGy/MBq for liver metastases (i.e., 56 and ≃10 mGy/MBq for ⁹⁰Y-DOTA-lanreotide, respectively). After four infusions of ⁹⁰Y- DOTA-lanreotide (each 1 GBq, ≃30 nmol) over a 6-mo period, the ¹¹¹In- DOTA-lanreotide scintigraphy of the liver had returned to a nearly normal condition and a remarkably decreased uptake by the recurrent gastrinoma was calculated (≃5 mGy/MBq for ⁹⁰Y-DOTA-lanreotide). The imaging results were well-correlated with a 25% regression of the liver metastases as indicated by CT. Blood, urine and whole-body clearances of ¹¹¹In-DOTA-lanreotide and ⁹⁰Y-DOTA-lanreotide were very similar. The DOTA-lanreotide promises to be useful for functional tumor diagnosis (¹¹¹In-DOTA-lanreotide) and receptor-mediated tumor radiotherapy (⁹⁰Y-DOTA-lanreotide).