: Cells are most sensitive to radiation during certain phases of the cell cycle (like mitosis). Fractionating treatment (giving it in small daily doses) allows surviving cancer cells to move into these sensitive phases.
: Normal cells are often better at repairing sublethal DNA damage than cancer cells. Basic Radiotherapy Physics and Biology
Not all radiation is created equal. The describes how much energy a particle deposits as it travels through tissue: : Cells are most sensitive to radiation during
Radiotherapy is a cornerstone of modern cancer treatment, utilized by approximately 50% of all cancer patients. But how does a beam of energy actually "cure" a disease? The answer lies at the intersection of —the science of how energy interacts with matter—and radiation biology —the study of how living cells respond to that energy. 1. The Physics: Interaction of Radiation with Matter Not all radiation is created equal
: Different tissues have inherent differences in how they respond to radiation. For example, lymphocytes and bone marrow are highly sensitive, while muscle and nerve tissues are more resistant. 3. High-LET vs. Low-LET Radiation
: Between treatments, both normal and tumor cells begin to grow again. The trick is to ensure the "kill rate" exceeds the "growth rate".
: These deposit energy sparsely. Most of their damage is indirect and easily repairable by healthy cells.