Status quo and directions in deep head and neck hyperthermia

Abstract

The benefit of hyperthermia as a potent modifier of radiotherapy has been well established and more recently also the combination with chemotherapy was shown beneficial. Also for head and neck cancer, the impact of hyperthermia has been clinically demonstrated by a number of clinical trials. Unfortunately, the technology applied in these studies provided only limited thermal dose control, and the devices used only allowed treatment of target regions close to the skin. Over the last decade, we developed the technology for deep and controlled hyperthermia that allows treatment of the entire head and neck region. Our strategy involves focused microwave heating combined with 3D patient-specific electromagnetic and thermal simulations for conformal, reproducible and adaptive hyperthermia application. Validation of our strategy has been performed by 3D thermal dose assessment based on invasively placed temperature sensors combined with the 3D patient specific simulations. In this paper, we review the phase III clinical evidence for hyperthermia in head and neck tumors, as well as the heating and dosimetry technology applied in these studies. Next, we describe the development, clinical implementation and validation of 3D guided deep hyperthermia with the HYPERcollar, and its second generation, i.e. the HYPERcollar3D. Lastly, we discuss early clinical results and provide an outlook for this technology.

Deep hyperthermia with the HYPERcollar system combined with irradiation for advanced head and neck carcinoma – a feasibility study

“…Given this ability of hyperthermia to enhance outcome without increasing toxicity [16], it seems reasonable to further study the combination of radiotherapy with hyperthermia for HNC. The development of the HYPERcollar has made it possible to extend the application of hyperthermia from superficial to deeply located HNC [17].…”

Heat-induced BRCA2 degradation in human tumours provides rationale for hyperthermia-PARP-inhibitor combination therapies

“…During hyperthermia treatment, external applicators are positioned in such a way that the temperature of the tumour is elevated to [40][41][42][43][44] C. Hyperthermia application devices have been designed to heat various tumour types in a localised fashion. A broad range of tumours can be treated with hyperthermia including, but not limited to, those occurring in the breast [3,4], cervix [5,6], head and neck [7,8], and bladder [9][10][11], resulting in growing interest for using hyperthermia as a means to increase the effectiveness and specificity of cancer treatment while minimising side-effects [12].…”

Hyperthermia treatment planning guided applicator selection for sub-superficial head and neck tumors heating

“…applicator type and position, amplitude, phase, water bolus temperature) to maximise the heat delivery in the CTV. At our institute, HTP is mandatory prior to HYPERcollar treatments to optimise amplitude and phase settings for each channel in the phase array, and the patient position in the applicator [11,12,16]. HTP also ensures that the specific absorption rate (SAR) in critical tissues such as spinal cord does not exceed safety limits of 60 W/kg [13].…”

“…For 24 representative patients, we retrospectively compared quality of hyperthermia treatments using HTP for the HYPERcollar, LCA and CSA applicators. HTP for the HYPERcollar was done following our standard clinic procedure [16] and superficial HTP setups for LCA and CSA were created manually by an experienced physicist. Heating quality was assessed using the predicted specific absorption rate (SAR) and temperature coverages of the CTV.…”