The low-energy β⁻ and electron emitter ¹⁶¹Tb as an alternative to ¹⁷⁷Lu for targeted radionuclide therapy

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• 作者：Silvia Lehenberger^a ; Christoph Barkhausen^a ; Susan Cohrs^b ; Eliane Fischer^b ; Jü ; rgen Grü ; nberg^b ; Alexander Hohn^b ; Ulli Kö ; ster^c ; Roger Schibli^b ; Andreas Tü ; rler^a ; ^d ; ^e ; Konstantin Zhernosekov^a ; ^b ; ^d ; ^{konstantin.zhernosekov@psi.ch"" rel=""nofollow}
• 关键词：Radionuclide therapy ; Radiolanthanides ; Specific activity ; DOTA-peptides
• 刊名：Nuclear Medicine and Biology
• 出版年：2011
• 出版时间：August 2011
• 年：2011
• 卷：38
• 期：6
• 页码：917-924
• 全文大小：269 K

文摘

Introduction

The low-energy β⁻ emitter ¹⁶¹Tb is very similar to ¹⁷⁷Lu with respect to half-life, beta energy and chemical properties. However, ¹⁶¹Tb also emits a significant amount of conversion and Auger electrons. Greater therapeutic effect can therefore be expected in comparison to ¹⁷⁷Lu. It also emits low-energy photons that are useful for gamma camera imaging.

Methods

The ¹⁶⁰Gd(n,γ)¹⁶¹Gd→¹⁶¹Tb production route was used to produce ¹⁶¹Tb by neutron irradiation of massive ¹⁶⁰Gd targets (up to 40 mg) in nuclear reactors. A semiautomated procedure based on cation exchange chromatography was developed and applied to isolate no carrier added (n.c.a.) ¹⁶¹Tb from the bulk of the ¹⁶⁰Gd target and from its stable decay product ¹⁶¹Dy. ¹⁶¹Tb was used for radiolabeling DOTA-Tyr3-octreotate; the radiolabeling profile was compared to the commercially available n.c.a. ¹⁷⁷Lu. A ¹⁶¹Tb Derenzo phantom was imaged using a small-animal single-photon emission computed tomography camera.

Results

Up to 15 GBq of ¹⁶¹Tb was produced by long-term irradiation of Gd targets. Using a cation exchange resin, we obtained 80 % –90 % of the available ¹⁶¹Tb with high specific activity, radionuclide and chemical purity and in quantities sufficient for therapeutic applications. The ¹⁶¹Tb obtained was of the quality required to prepare ¹⁶¹Tb–DOTA-Tyr3-octreotate.

Conclusions

We were able to produce ¹⁶¹Tb in n.c.a. form by irradiating highly enriched ¹⁶⁰Gd targets; it can be obtained in the quantity and quality required for the preparation of ¹⁶¹Tb-labeled therapeutic agents.