[177Lu-DOTAOTyr3]octreotate: comparison with [111In-DTPAo]octreotide in patients

• Published in: European Journal of Nuclear Medicine Vol. 28; no. 9; pp. 1319 - 1325
• Main Authors: Kwekkeboom, D J, Bakker, W H, Kooij, P P, Konijnenberg, M W, Srinivasan, A, Erion, J L, Schmidt, M A, Bugaj, J L, de Jong, M, Krenning, E P
• Format: Journal Article
• Language: English
• Published: Germany Springer Nature B.V 01-09-2001
• Subjects: Adolescent; Adult; Aged; Female; Humans; Indium Radioisotopes - pharmacokinetics; Lutetium - pharmacokinetics; Male; Middle Aged; Neoplasms - chemistry; Neoplasms - diagnostic imaging; Neoplasms - radiotherapy; Octreotide - analogs & derivatives; Organometallic Compounds - pharmacokinetics; Radiation Dosage; Radioisotopes - pharmacokinetics; Radionuclide Imaging; Radiopharmaceuticals - pharmacokinetics; Radiopharmaceuticals - therapeutic use; Receptors, Somatostatin - analysis; Somatostatin - analogs & derivatives; Somatostatin - pharmacokinetics
• ISSN: 0340-6997; 1619-7070; 1619-7089
• DOI: 10.1007/s002590100574

The somatostatin analogue [DOTA0,Tyr3]octreotate has a nine-fold higher affinity for the somatostatin receptor subtype 2 as compared with [DOTA0, Tyr3]octreotide. Also, labelled with the beta- and gamma-emitting radionuclide lutetium-177, this compound has been shown to have a very favourable impact on tumour regression and animal survival in a rat model. Because of these reported advantages over the analogues currently used for somatostatin receptor-mediated radiotherapy, we decided to compare [177Lu-DOTA0,Tyr3]octreotate (177Lu-octreotate) with [111In-DTPA0]octreotide (111In-octreotide) in six patients with somatostatin receptor-positive tumours. Plasma radioactivity after 177Lu-octreotate expressed as a percentage of the injected dose was comparable with that after 111In-octreotide. Urinary excretion of radioactivity was significantly lower than after 111In-octreotide, averaging 64% after 24 h. The uptake after 24 h, expressed as a percentage of the injected dose of 177Lu-octreotate, was comparable to that after 111In-octreotide for kidneys, spleen and liver, but was three- to fourfold higher for four of five tumours. The spleen and kidneys received the highest absorbed doses. The doses to the kidneys were reduced by a mean of 47% after co-infusion of amino acids. It is concluded that in comparison with the radionuclide-coupled somatostatin analogues that are currently available for somatostatin receptor-mediated radiotherapy, 177Lu-octreotate potentially represents an important improvement. Higher absorbed doses can be achieved to most tumours, with about equal doses to potentially dose-limiting organs; furthermore, the lower tissue penetration range of 177Lu as compared with 90Y may be especially important for small tumours.