Heat distribution improvement with the implementation of polyethylene-covered water bolus into breast cancer hyperthermia

Abstract

This paper presents the implementation of polyethylene-covered water bolus into a non-invasive breast cancer hyperthermia applicator. This modified hyperthermia applicator is introduced to improve the performance of hyperthermia by reducing or removing unwanted hotspots during hyperthermia treatment. This simulation-based experiment is carried out to observe the heating distribution of hyperthermia with water bolus coated by three different thicknesses of polyethylene cover or layer, which are 0.5mm, 0.8mm and 1.0mm. The solvent used in the water bolus is distilled water. The 915MHz microstrip antenna as a hyperthermia applicator and stage 2 breast cancer with a cancer depth of 28.6 mm to 73.6 mm is selected for this study. Based on the results, with the modified HTP integrated by water bolus, the heat pattern of hyperthermia simulation becomes more concentrated into the targeted cancer region, and unwanted hotspots nearby the skin area of breast tissue are removed. The 0.5mm thick polyethylene cover showed the best results with a focusing region between 29.4mm to 69.4mm compared with the result of hyperthermia without implemented water bolus, which heated the 26.6mm to 67.3mm region.