Matched-pair, 86Y/90Y-labeled, bivalent RGD/bombesin antagonist, [RGD-Glu-[DO3A]-6-Ahx-RM2], as a potential theranostic agent for prostate cancer

Abstract

The theranostic, heterobivalent, agents described herein perform comparably with other mono- and multivalent conjugates we have reported and offer the potential of improved sensitivity for detecting prostate cancer cells that might exhibit differing profiles of receptor expression on tumor cells in human patients.

Radiometals for imaging and theranostics, current production, and future perspectives

“…86 Y ( T 1/2 = 14.7 h) decays by electron capture (EC) (66%) and β + (34%) with E β + max = 3.2 MeV and has been used as a PET imaging surrogate for the therapeutic radionuclide 90 Y . It can be produced in low‐energy cyclotrons via the reaction 86 Sr(p,n) 86 Y or 86 Sr(d,2n) 86 Y using carbonate or oxide targets .…”

“…39,40 In particular, the therapeutic utility of 90 Y-labelled somatostatin-receptor targeting peptides, when used either alone 41,42 or in combination therapy, [43][44][45] has been demonstrated over the last two decades. 86 46 It can be produced in low-energy cyclotrons via the reaction 86 Sr(p,n) 86 Y or 86 Sr(d,2n) 86 Y using carbonate or oxide targets. 47 However, the targetry is challenging, and the physical properties of 86 Y have some limitations, such as the high-energy gamma emission (more than 65% of 86 Y decays are accompanied by additional γ-rays with energies from 200 to 3000 keV), 48 which contribute to the patient radiation dose.…”

“…The drawback of the abovementioned production routes is the fact that the availability of cyclotrons with high-current α beams, or those with deuteron beams, is limited. 78 Recently, the production of 43 Sc was investigated, comparing two different production routes, namely, 46 Ti(p,α) 43 Sc and 43 Ca(p,n) 43 Sc. 78 The former nuclear reaction has a low cross section and resulted in a product with modest yield after extensive irradiation of 97% enriched 46 Ti metal powder with protons at approximately 17 MeV but high radionuclidic purity (>98%).…”

“…78 Recently, the production of 43 Sc was investigated, comparing two different production routes, namely, 46 Ti(p,α) 43 Sc and 43 Ca(p,n) 43 Sc. 78 The former nuclear reaction has a low cross section and resulted in a product with modest yield after extensive irradiation of 97% enriched 46 Ti metal powder with protons at approximately 17 MeV but high radionuclidic purity (>98%). The production via the 43 Ca(p,n) 43 Sc nuclear reaction produced higher activities of 43 Sc, but the product consisted of a mixture of 43 Sc and 44 Sc at an activity ratio of 2:1 when using 57.9% enriched 43 CaCO 3 and irradiating with approximately 11 MeV protons to maximize 43 Sc production over its 44 Sc counterpart.…”

“…PET images of Derenzo phantoms were acquired using 44 Sc from irradiated 44 Ca targets, as well as 43 Sc obtained from both 46 Ti-and 43 Ca-irradiated target material. 78 In line with the smaller positron energy of 43 Sc, the resolution was found to be the best for pure 43 Sc, followed by the 43 Sc/ 44 Sc mixture and 44 Sc.…”