Comparative evaluation of radionuclide therapy using ⁹⁰Y and ¹⁷⁷Lu

Area of Science:

• Nuclear medicine
• Radiopharmaceutical therapy
• Oncology

Background:

• Yttrium-90 (90Y) and Lutetium-177 (177Lu) are clinically used beta-emitters for radionuclide therapy.
• Comparative studies evaluating 90Y- and 177Lu-labeled molecules are limited.

Purpose of the Study:

• To compare the therapeutic features of 90Y and 177Lu in preclinical tumor models.
• To assess the impact of tumor growth rate on the efficacy of 90Y- and 177Lu-labeled antibodies.

Main Methods:

• Utilized two tumor cell lines with differing growth rates in mice.
• Conducted biodistribution studies of 177Lu-labeled antibodies (177Lu-Abs).
• Assessed therapeutic effects of 90Y- and 177Lu-Abs and estimated absorbed radiation dose using Monte Carlo simulation.

Main Results:

• 177Lu-Abs showed high tumor accumulation in both models.
• 90Y-Ab demonstrated superior therapeutic effect in fast-growing tumors due to higher absorbed dose.
• Both 90Y- and 177Lu-Abs were effective in slow-growing tumors, with 177Lu-Ab providing longer efficacy due to its longer half-life and better dose uniformity.

Conclusions:

• The choice between 90Y and 177Lu for radionuclide therapy should be tailored to the specific cancer's growth rate.
• Optimizing therapeutic outcomes requires considering the radioisotope's properties in relation to tumor characteristics.