C i.e. Mycosis fungoides High energy linear accelerators produce electron beam (f-paicle) and high energy (megavoltage) X-rays by bremsstrahlung interactionQ. High energy cyclotron accelerates proton, deutron & a paicles producing high energy proton beams or fast neutronsQ. In linear accelerator, electrons are accelerated in straight line to high energy & are allowed to exit the machine as electron beam (for treatment of superficial cancers eg mycosis funguidesQ as paicle therapy) or are directed to a target to produce high energy (megavoltage) bremsstrahlung X-rays (to treat deep seated tumors). Betatron & Van de Graff accelerator also accelerate electrons. Cyclotron can accelerate proton, dentron and alpha paicles spirally to 35 MeV energy and can generate proton & neutrons beamsQ and other high energy charged paicles Gamma rays (y) photons are generated from decay of atomic nuclei of radioisotopes such as Cobalt & radium. X-Rays was first produced by Rontgen in 1895. Now a days X-Rays are produced by cooling tube. X Rays are produced when fast moving stream of electron produced by cathodeQ (negative charged tungsten filament) strikes the anodeQ (positive charged tungsten or molybdenum containing copper block). Scattering depends on Electron/Nucleus ratio. X-Ray is most scattered by H+ionQ. The period when fetus is most sensitive to radiation is 8-15 weeks of gestationsQ. X RaysQ & Gamma raysQ are the forms of radiation most commonly used to treat cancer. Xrays (generated by linear accelerator) and gamma rays (generated by decay of atomic nuclei of radio isotopes) are both electromagnetic, non-paiculate, non charged, zero mass, packets of energy (photons) waves that cause ejection of an orbital electron when absorbed (i.e. ionization) and kill-tumor cells by producing double strand breaks in DNA (direct) or free radicle production (indirect). Paiculate forms of radiation are also use in ceain circumstances. Total skin electron treatment (TSET) which is similar to total body irradiation (TBI) except that electrons are used instead of photons. TSET have a very low tissue penetration and are used to treat skin cancer such as mycosis fungoidesQ. The main advantage of liner accelerator is the ability to produce X-rays and electrons of varying energy within the same machine.