Somatostatin receptors type 2 (sst2) are expressed in high concentration on numerous neudoendocrine tumors. The successful use of radiolabeled somatostatin analogs in imaging promoted further studies in utilizing them in radiopeptide therapy. The somatostatin analog 90Y-DOTA-D-Phe1-Try3]octreotide (DOTATOC) (DOTA: 1,4,7,10-tetraazacyclododecane-N,N′,N″,N‴-tetraacetic acid) possesses favorable characteristic for its therapeutic use; shows high affinity for sst2, moderately high affinity for sst5, and intermediate affinity for sst3; high hydrophilicity; stable and facile labeling with 111 In and 90 Y. In this article we report our experience with 90Y-DOTATOC in neuroendocrine tumors. Eighty-seven patients with neuroendocrine tumors were treated with a cumulated activity ranging from 7.4 to 20.2 GBq. Most patients responded with stabilization of disease (48%); however, objective responses were observed in 28% of patients (5% complete response). No major acute reactions were observed up to the activity of 5.55 GBq per cycle. The dose limiting was bone marrow toxicity and the maximal tolerated dose was defined as 5.18 GBq.
- Y-DOTA-D-Phe-Try-Octreotide (Y-DOTATOC)
- Neuroendocrine tumors
- Radiopeptide therapy
- Somatostatin analogs
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)