Medical Physics - Board Exam Part 1 - Radiation Therapy | 109 Questions And Answers With Complete Solutions 100% Correct | Latest Update 2024

As the incident electron energy increases from 6 MeV to 20 MeV, the skin dose: {Ans: Increases - as electron energy increases, the skin dose increases}Range of energies for proton therapy {Ans: 70-250 MeV}Photon Dmax (cm) - 6MV {Ans: 1.5}The primary advantage of protons compared to photons in radiation therapy is {Ans: limited range - penumbra is only sharper for short ranges}Skin dose is dependent on the following factors {Ans: Decreases with beam energy Increases with SSD Increases with field size Increases with bolus Increases with oblique incidence}Photon field flatness—i.e., the variation of dose relative to the central axis over the central 80% of a 10-by-10 field size—should be measured at a depth of _____. A dose variation of _____ is considered acceptable {Ans: 10 cm, +3%}How is small field dosimetry characterized? {Ans: by lateral electronic disequilibrium}Electron Dmax (cm) - 10MeV {Ans: 2.5}Formula to calculate depth of 10% isodose line for electron therapy {Ans: E/2.2 cm ?}Define TSEB {Ans: Total Skin Electron Beam Therapy}Average energy for Cs-137 {Ans: 662 keV}Tolerances for translational and rotational treatment couch position indicators for non-IMRT treatments and IMRT treatments {Ans: 2 mm; 1