adding 166ho data to varskin2 code and dose calculation to human skin

background: skin cancer can be treated by various methods. electron radiotherapy has been a useful therapeutic modality in the treatment of skin cancers in areas which are difficult to cure by other methods. depth dose distribution of 166ho using varskin2 code is presented in this work. material and methods: depth dose distribution of 166ho was calculated, using varskin2 code by adding of 166ho data to the library of varskin2 code. after adding 166ho radionuclide data to the library of the code, it was run for various input parameters including: density, air gap thickness, radiation time and different source geometry. different forms of sources which have been used in this research are 2-d disk, cylindrical and spherical shapes. results: the result showed that the skin absorbed depth dose variation was an exponential function because of short range of beta ray. dose gradient was very high near the sources. for the same activity, disk source induced a dose more than spherical and cylindrical source to skin surface. conclusion: superficial skin tumors could be successfully treated by topical application of beta-emitting 166ho source. varskin2 is a fast, accurate and user friendly code for beta dosimetry and can be used for dose optimization calculation, especially in beta source over the human skin. iran. j. radiat. res., 2010 8 (1): 45-49