Individualized phantom based on CT slices and auxological data (ICTA) for dose estimations following radiotherapy for skin haemangioma in childhood

Background and purpose: Before 1974 about 5000 children were treated by rad iotherapy at the Institut Gustave-Roussy (IGR) for a skin haemangioma. A hu man model whose characteristics are as close as possible to those of the pa tient at the time of the treatment is necessary to effectuate an accurate r etrospective estimation of the radiation doses received at distant organs. Methods: We have developed a software package which constructs an individua lized phantom based on CT slices and auxological data (ICTA) for this purpo se. A set of real CT slices is used to produce a 3-D representation of the human body which is then adjusted to fit the dimensions supplied by publish ed auxological data relative to sex and age for each patient. One hundred s ixty-one anatomical landmarks of epidemiological interest have been defined inside the phantom for dose estimation. Results: The transverse, frontal and sagittal views of the phantom displaye d permit accurate positioning of radioactive applicators. The software calc ulates the relevant parameters required for dose estimation based on the pa tient's probable anatomy. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.