Lu177labeled

Lu-177 labeled compounds are radiopharmaceuticals in which lutetium-177 is bound to a biological targeting molecule via a chelator, most commonly DOTA. The resulting agents deliver targeted beta radiation to tumor tissue while emitting gamma photons that enable imaging, supporting diagnostic monitoring and dosimetry. This combination of therapy and imaging gives rise to a theranostic approach in nuclear medicine.

Commonly used chelators and vectors define the landscape of Lu-177 labeling. DOTA forms stable complexes with Lu-177 under mild heating and slightly acidic conditions. Targeting vectors include somatostatin analogs such as DOTATATE and PSMA inhibitors such as PSMA-617. Prominent examples are Lu-177-DOTATATE (used for neuroendocrine tumors) and Lu-177-PSMA-617 (used for metastatic prostate cancer), with research exploring additional targets and ligands.

Production and physical properties of Lu-177 are well established. The isotope has a half-life of about 6.65 days and decays by beta emission with a maximum energy near 0.497 MeV, while also emitting gamma photons suitable for single-photon emission computed tomography (SPECT) imaging. In clinical use, Lu-177 is typically produced in nuclear reactors by neutron irradiation of Lu-176 targets, with various routes aiming to achieve suitable specific activity for labeling.

Clinical use and regulatory status include several approved Lu-177 therapies. 177Lu-DOTATATE (Lutathera) is approved for unresectable or metastatic well-differentiated neuroendocrine tumors, and 177Lu-PSMA-617 (Pluvicto) is approved for metastatic castration-resistant prostate cancer after at least one prior therapy. Standard regimens involve multiple cycles at intervals (often every 6 weeks) following confirmation of target expression by imaging.

Safety considerations include potential hematologic suppression, renal toxicity, dry mouth, and nausea. Treatment requires specialized facilities and radiation protection, with patient selection guided by tumor receptor expression and overall clinical status. Ongoing research seeks new targets, chelators, and combination approaches to expand the utility of Lu-177 labeling.