Abstract

Lutetium-177 has been widely discussed as a radioisotope of choice for targeted radionuclide therapy. The simultaneous emission of imageable gamma photons [208 keV (11%) and 113 keV (6.4%)] along with particulate β^- emission [β_(max) = 497 keV] makes it a theranostically desirable radioisotope. In the present article, the possibility of using two ¹⁷⁷Lu-based agents viz. ¹⁷⁷Lu-EDTMP and ¹⁷⁷Lu-DOTATATE for theranostic applications in metastatic bone pain palliation (MBPP) and peptide receptor radionuclide therapy (PRRT), have been explored. In the case of ¹⁷⁷Lu-EDTMP, the whole-body images obtained are compared with those recorded using ^99mTc-MDP in the same patient. On the other hand, pre-therapy images acquired with ¹⁷⁷Lu-DOTA-TATE are compared with similar images obtained with standard agents, such as ^99mTc-HYNIC-TOC (SPECT) and ⁶⁸Ga-DOTA-TOC (PET) in the same patient. The advantage of the long physical half-life (T_1/2) of ¹⁷⁷Lu has been utilized in mapping the pharmacokinetics of two additional agents, ¹⁷⁷Lu-labeled hydroxyapatite (HA) in radiation synovectomy of knee joints and ¹⁷⁷Lu-HA for therapy of hepatocellular carcinoma. Results of these multiple studies conclusively document the potential of ¹⁷⁷Lu as a theranostic radioisotope

Keywords: ¹⁷⁷Lu, Theranostic applications, Metastatic bone pain palliation, Peptide receptor radionuclide therapy, Pharmacokinetic mapping.