Radiotherapy
The clinical treatment of malignant cancer tumors using precisely targeted ionizing radiation beams to induce double-strand DNA damage in cancer cells.
Governing formula
Linear-Quadratic Cell Survival: S = exp(-α D - β D²)
SI unit
Gy (Gray = J/kg) Total Prescribed Dose
In depth
Ionizing radiation creates free radicals that destroy cancer cell DNA. Fractionated dose schedules exploit differential repair capabilities between normal and malignant tumor tissue.
Examples in the real world
Intensity-Modulated Radiation Therapy (IMRT) delivering high conformal doses to prostate tumors while sparing healthy bladder tissue.