Biophysics & Medical Physics
5 terms
Radiation Dosimetry
Biophysics & Medical Physics
Gy (Gray = J/kg)
The subfield of medical physics quantifying and measuring ionizing radiation energy deposited in human tissues or phantom materials.
D = dĒ / dm (Absorbed Energy per Unit Mass)
Radiobiology
Biophysics & Medical Physics
Gy (Dose Response Units)
The study of the biological mechanisms and health effects of ionizing radiation acting on living cells and biological tissues.
DNA Double-Strand Breaks (DSB) ~ 35–40 per Gy per Cell
Radiopharmaceuticals
Biophysics & Medical Physics
MBq or mCi (Administered Activity)
Pharmaceutical compounds containing radioactive isotopes administered to patients for target-specific diagnostic imaging or therapy.
Targeted Radionuclide Compound: Radiotracer + Carrier Molecule
Radiotherapy
Biophysics & Medical Physics
Gy (Gray = J/kg) Total Prescribed Dose
The clinical treatment of malignant cancer tumors using precisely targeted ionizing radiation beams to induce double-strand DNA damage in cancer cells.
Linear-Quadratic Cell Survival: S = exp(-α D - β D²)
Relative Biological Effectiveness (RBE)
Biophysics & Medical Physics
Dimensionless Ratio
The ratio of absorbed dose of a reference 250 kVp X-ray beam to the absorbed dose of a test radiation type required to produce an identical biological effect.
RBE = D_reference (250 kVp X-rays) / D_test (for equal biological effect)