3D virtual reconstruction of RF applicators positions in a bone hyperthermia therapy; towards a hyperthermia treatment planning

Abstract

According to American Cancer Society by 2022 nearly 4,000 new cases of bone cancer will be diagnosed. Oncological hyperthermia is a treatment where the temperature of the tumor rises between 40°C - 45°C for a time between 60 min. - 90 min. Hyperthermia Treatment Planning (HTP) is used to predict energy absorption patterns and temperature distributions, through a specific configuration of the applicators. Therefore, it is necessary to know the position of the radiofrequency (RF) applicators that will be used. In this work the coordinates (x, y, z & θ) of the vertices of two non-functional RF applicators used in the emulation of a hyperthermia treatment were obtained through a 3D reconstruction based on photographs. 250 images were used to obtain the 3D reconstruction using the algorithm Structure from Motion (SfM). Obtaining a minimum error rate of 17.35% between the actual distance of the applicators and the 3D reconstruction of these. Subsequently, in Matlab, the vertices coordinates (x, y, z & θ) of both applicators were obtained in approximately 5 minutes. This information will be used in a modeling software to know the interaction of the energy provided by the applicators to aid in a future implementation of a HTP.