Comparison between Targeted Radionuclide Therapy of Bone Metastases Based on beta-Emitting and alpha-Emitting Radionuclides

摘要

Introduction: The a- and β-emitter radionuclides are used for palliative treatment of bone metastasis. Our objective was to compare the dosimetric parameters of radionuclides used in bone pain palliation therapy. Methods: Monte Carlo code, MCNPX, was used to simulate radiation transport. Dosimetric calculations were performed for monoe-nergetic electrons with energies of 0.1-3 MeV, α-particles with energies of 3-10 MeV, and several radionuclides ~32P, ~89Sr, ~153Sm, ~177Lu, ~223Ra, and its progeny. The simulated phantom consisted of bone marrow, an endosteal layer, bone, and soft tissue. Source tissues included bone marrow, endosteal layer, and bone. Absorbed fractions and specific absorbed fractions were calculated for target regions. Absorbed doses were calculated for investigated radionuclides. Results: The obtained results demonstrated that the dosimetric parameters vary depending on the source or target size, particle energy, and location of the source. The β-emitter radionuclides were able to penetrate the bone marrow region, whereas the α-emitter radionuclides gave a higher and localized dose to the bone and endosteal layer in comparison. Conclusion: Ra and Lu have fewer side effects on the bone marrow, and they may be a better choice for use in bone pain palliation radiotherapy.