INTEGRAL DOSEの近似計算式 : ⁶⁰Co照射に関して

抄録

Since there have been reported many calculating formulas to simulate the integral dose in radiation teletherapy, there were few formulas which were enough simple and applicable in routine clinical application. Based on the interaction of gamma photon with scattering medium and the concept of energy flux, a new simulating equation, for 60-cobalt gamma ray irradiation, is considered. Integral Dose [g-rad] [numerical formula] Dd : tumor does (depth d) [rad] (μ_<en>/ρ) med : mass energy absorption coefficient (0.0295) A : field area at depth d [cm^2] Th : thickness of irradiated body [cm] The equation can be of wide application, because the error range of the value calculated by this equation to the value by integration the dose from the curve of the isodose chart is independent on the field size and the thickness of irradiated body. And it can be adaptable in moving and conformation teletherapies. When the value of average skin-rotation axis distance, average field size and average thickness of irradiated body are introduced.