title: IVBTMC, a Monte Carlo dose calculation tool for intravascular brachytherapy.
abstract: A new Monte Carlo code (IVBTMC) is developed for accurate dose calculations in intravascular brachytherapy (IVBT). IVBTMC calculates the dose distribution of a brachytherapy source with arbitrary size and curvature in a general three-dimensional heterogeneous medium. Both beta and gamma sources are considered. IVBTMC is based on a modified version of the EGSNRC code. A voxel-based geometry is used to describe the target medium incorporating heterogeneities with arbitrary composition and shape. The source term is modeled using appropriate phase-space data. The phase-space data are calculated for three widely used sources (32P, 90Sr/90Y, and 192Ir). To speed up dose calculations for gamma sources, a special version of IVBTMC based on the kerma approximation is developed. The accuracy of the phase-space data model is verified and IVBTMC is validated against other Monte Carlo codes and against reported measurements using radio-chromic films. To illustrate the IVBTMC capabilities, a variety of examples are treated. 32P, 90Sr/90Y, and 192Ir sources with different lengths and degrees of curvature are considered. Calcified plaques with regular and irregular shapes are modeled. The dose distributions are calculated with a spatial resolution ranging between 0.1 and 0.5 mm. They are presented in terms of isodose contour plots. The dosimetric effects of the source curvature and/or the presence of calcified plaques are discussed. In conclusion, IVBTMC has the capability to perform high-precision IVBT dose calculations taking into account the realistic configurations of both the source and the target medium.
authors.affiliation: Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA. o_chibani@fccc.edu
authors.forename: Omar
authors.initials: O
authors.lastname: Chibani
authors.forename: X Allen
authors.initials: XA
authors.lastname: Li
mesh_terms: D001918:Brachytherapy / Q000379:methods*; D002114:Calcinosis / Q000532:radiotherapy; D003198:Computer Simulation; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D009010:Monte Carlo Method; D010761:Phosphorus Radioisotopes / Q000627:therapeutic use; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012680:Sensitivity and Specificity; D012984:Software; D013326:Strontium Radioisotopes / Q000627:therapeutic use; D014652:Vascular Diseases / Q000532:radiotherapy*; D015021:Yttrium Radioisotopes / Q000627:therapeutic use
chemical_list: D007496:Iridium Radioisotopes; D010761:Phosphorus Radioisotopes; D013326:Strontium Radioisotopes; D015021:Yttrium Radioisotopes