Comparison of different types of radioactivity
As dose limiting organs influence the amount of radiopharmaceutical that is delivered to patients, it is important to understand the relationships between radiation dose (Gy) and biological effects, especially the comparative relationships between radionuclides emitting Auger electrons, beta particles, and X-rays.
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Example 1. Comparing Auger electron and beta particle-emitters to X-rays in vitro and in vivo
Example 2. Using the plasmid assay to relate external beam radiotherapy to radionuclide therapy
The biological consequences of absorbed radiation doses are ill-defined for radiopharmaceuticals, unliked for external beam radiotherapy. A reliable assay that assesses the biological consequences of any radionuclide is much needed. Here, we evaluated the cell-free plasmid DNA assay to determine the relative biological effects of radionuclides such as Auger electron-emitting 67Ga or 111In compared to EBRT. This figure shows that to get the same damage from 1 Gy of photon radiation, incubation with 0.5 MBq 67Ga is needed for 2 hours whereas 9 hours is needed for 111In. From Verger et al. 2021
Despite a rise in clinical use of radiopharmaceutical therapies, the biological effects of radionuclides and their relationship with absorbed radiation dose are poorly understood. Here, we set out to define this relationship for Auger electron-emitters [99mTc]TcO4 and [123I]I, and β−-particle-emitter [188Re]ReO4. Studies were carried out using genetically-modified cells that permitted direct radionuclide comparisons. From Costa et al. 2024