Development of a Clinical Head and Neck Hyperthermia Applicator

Abstract

Treatment of advanced tumours in the head and neck \n(H&N) remains complex and the toxicity related to the currently \nstandard treatment modalities is a major issue. For many tumour \nsites, the addition of hyperthermia (HT) to radiotherapy has been \nshown to result in improved local control rates and/or better overall \nsurvival rates. HT has a high potential to improve cancer treatment \nresults in H&N patients as well without adding toxicity. However, an \nappropriate applicator that can heat both superficially and deeply \nlocated target sites in the H&N region is currently not available.\nThis thesis describes the items that needed to be addressed to design \nand build such an applicator. Extensive theoretical parameters \nstudies were performed 1) to show the feasibility of deep heating in \nthe H&N using radiofrequency (RF) waves and 2) to guide the design of \nthe applicator. These parameter studies were performed using \nelectromagnetic (EM) simulation programs. The predictions were then \nverified by measurements and with their results we designed and build \na clinical prototype (the HYPERcollar applicator). We performed \ntreatment planning for several patients to establish the specific \nabsorption rate (SAR) patterns that are achievable with this \napplicator. In a heating session of the first patient of an ongoing \nclinical feasibility study we showed the possibility of deep heating \nusing the HYPERcollar applicator