Fractionated radiotherapy; Radiation therapy
Medical treatment that typically delivers a dose of ionizing radiation high enough to induce cell death in a specific target cell population (e.g., tumor cells).
Sources of ionizing radiation include high-energy photons, X-rays, and gamma rays. Gamma rays are photons released from the nucleus of a radioactive atom (i.e., Iodine-125), and X-rays are photons created electronically. Doses are measured in units of radiation absorbed per unit of tissue. Typically, this is expressed in Grays (1 J/kg tissue). Radiotherapy-induced cell death typically occurs through two mechanisms: direct and indirect ionization. Direct ionization induces cell damage directly in cell DNA while indirect ionization induces the ionization of water molecules, thus forming free radicals (i.e., hydroxyl radicals), which also lead to cell injury and death. Additionally, radiation therapy can affect cell cycle processes needed for...
References and Readings
- Bomford, C. K., & Kunkler, I. H. (2003). Walter and Miller’s textbook of radiotherapy: Radiation physics, therapy and oncology (6th ed.). Edinburgh: Churchill Livingstone.Google Scholar
- Bucci, K., Bevan, A., & Roach, M. (2005). Advances in radiation therapy: Conventional to 3D, to IMRT, to 4D, and beyond. CA: A Cancer Journal for Clinicians, 55(2), 117–134.Google Scholar
- Schlegel, W., Bortfeld, T., & Grosu, A.-L. (Eds.). (2006). New technologies in radiation oncology. Heidelberg/Berlin: Springer.Google Scholar