Abstract.
Peptide receptor-targeted radionuclide therapy is nowadays also being performed with DOTA-conjugated peptides, such as [DOTA0,Tyr3]octreotate, labelled with radionuclides like 177Lu. The incorporation of 177Lu is typically ≥99.5%; however, since a total patient dose can be as high as 800 mCi, the amount of free 177Lu3+ (= non-DOTA-incorporated) can be substantial. Free 177Lu3+ accumulates in bone with unwanted irradiation of bone marrow as a consequence. 177Lu-DTPA is reported to be stable in serum in vitro, and in vivo it has rapid renal excretion. Transforming free Lu3+ to Lu-DTPA might reroute this fraction from accumulation in bone to renal clearance. We therefore investigated: (a) the biodistribution in rats of 177LuCl3, [177Lu-DOTA0,Tyr3]octreotate and 177Lu-DTPA; (b) the possibilities of complexing the free 177Lu3+ in [177Lu-DOTA0,Tyr3]octreotate to 177Lu-DTPA prior to intravenous injection; and (c) the effects of free 177Lu3+ in [177Lu-DOTA0,Tyr3]octreotate, in the presence and absence of DTPA, on the biodistribution in rats. 177LuCl3 had high skeletal uptake (i.e. 5% ID per gram femur, with localization mainly in the epiphyseal plates) and a 24-h total body retention of 80% injected dose (ID). [177Lu-DOTA0,Tyr3]octreotate had high and specific uptake in somatostatin receptor-positive tissues, and 24-h total body retention of 19% ID. 177Lu-DTPA had rapid renal clearance, and 24-h total body retention of 4% ID. Free 177Lu3+ in [177Lu-DOTA0,Tyr3]octreotate could be complexed to 177Lu-DTPA. Accumulation of 177Lu in femur, blood, liver and spleen showed a dose relation to the amount of free 177Lu3+, while these accumulations could be normalized by the addition of DTPA. After labelling [DOTA0,Tyr3]octreotate with 177Lu the addition of DTPA prior to intravenous administration of [177Lu-DOTA0,Tyr3]octreotate is strongly recommended.
Article PDF
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Electronic Publication
Rights and permissions
About this article
Cite this article
Breeman, W.A., van der Wansem, K., Bernard, B.F. et al. The addition of DTPA to [177Lu-DOTA0,Tyr3]octreotate prior to administration reduces rat skeleton uptake of radioactivity. Eur J Nucl Med 30, 312–315 (2003). https://doi.org/10.1007/s00259-002-1054-4
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s00259-002-1054-4