High Linear Energy Transfer & Range
The efficacy of Actinium-225 in TAT is attributed to its high linear energy transfer (LET). High LET radiation like alpha particles causes dense ionization along their tracks, leading to significant biological damage to targeted cells. This property is particularly advantageous in cancer treatment, where the goal is to maximize damage to cancer cells while minimizing the impact on surrounding healthy tissue.
Alpha particles exhibit a higher interaction frequency with matter compared to beta particles. Consequently, they more effectively ionize their surroundings. However, this increased potency comes at the cost of a shorter range, as alpha particles rapidly lose their initial energy due to frequent interactions. As a result, alpha particles cause greater damage to DNA and cells within a smaller volume when compared to beta particles.