Heating tumours precisely to make radiotherapy and chemotherapy more effective
Hyperthermia is the controlled heating of a tumour to about 39–44 °C. At these temperatures cancer cells become more sensitive to radiotherapy and chemotherapy, so hyperthermia is given in combination with those treatments rather than on its own.
Our work covers the whole chain from applicator design and patient-specific treatment planning to MR-guided temperature monitoring and clinical implementation, with a particular focus on deep hyperthermia in the head and neck.
In radiofrequency (RF) and microwave hyperthermia, an array of antennas around the patient deposits electromagnetic energy in the tumour. The main challenge is control: the tumour must reach therapeutic temperatures while healthy tissue, and especially critical structures such as the spinal cord or brain, stays safe. Clinical studies have shown that the thermal dose achieved in the tumour predicts the outcome, for example local control in cervical cancer treated with radiotherapy and hyperthermia.
Achieving a good thermal dose is hardest in anatomically complex regions. The head and neck region is a clear example: tumours lie close to critical tissues, and the anatomy, cooling by blood flow and tissue properties vary strongly between patients.
Deep hyperthermia in the head and neck was long considered impractical. During his PhD at Erasmus MC, Maarten Paulides designed the HYPERcollar, the first phased-array applicator for deep hyperthermia in this region. Its design was driven by electromagnetic simulation rather than trial and error. The first clinical treatments showed that patient positioning and temperature measurement were new challenges in their own right.
These lessons led to the redesigned HYPERcollar3D, in clinical use at Erasmus MC since 2015. Clinical studies have since reported the feasibility of deep head and neck hyperthermia combined with radiotherapy and outcomes after re-irradiation with hyperthermia. The technology is being brought to more hospitals through the medtech company Sensius, which Maarten Paulides co-founded, and is being evaluated further in the TANCA-I phase I trial.
Hyperthermia treatment planning uses a 3D patient model built from CT and MRI to predict where energy is absorbed (the specific absorption rate, SAR) and how the tissue heats. We contributed to implementing treatment planning in routine clinical hyperthermia in Rotterdam and to VEDO, a software tool that brings planning into the treatment room so that heating can be adapted in real time, for example when a patient reports a hot spot.
Planning also guides device design and applicator selection, and planning-based quality indicators help predict treatment quality. Read more on Computational Medicine.
Invasive temperature probes only measure at a few points. MR thermometry, based on the proton resonance frequency shift (PRFS), makes it possible to measure temperature non-invasively in 3D during treatment. We develop MR-compatible applicators such as the MRcollar for the head and neck, dual-function hardware that both heats and images, and methods that correct MR thermometry for motion and susceptibility artefacts.
Together with partners in the Netherlands and Germany, we assessed MR thermometry accuracy across institutions and MR-guided hyperthermia systems, developed imaging-based patient selection for MR-guided hyperthermia in cervical cancer, and evaluated MR thermometry in soft-tissue sarcoma with LMU Munich. Combining MR measurements with models and feedback control is the basis for adaptive hyperthermia. See Medical Imaging.
NWO Perspectief project on personalised MR-guided thermochemotherapy for breast-conserving surgery. TU/e principal investigator and work package leader.
Dutch Cancer Society public-private partnership on real-time absolute dose control in anti-cancer thermotherapy.
NWO and Dutch Cancer Society project on learning-based control for 3D adaptive MR-guided hyperthermia.
EUREKA Eurostars project on sensory-guided thermal therapy, with Sensius.
Erasmus MC Cancer Institute (Hyperthermia Unit, Radiation Oncology), LMU Munich and Czech Technical University in Prague.
European Society for Hyperthermic Oncology (ESHO), Thermotherapy Netherlands (TTNL) and the HYPERBOOST Marie Skłodowska-Curie network.
Hyperthermia is the controlled heating of a tumour to about 39–44 °C, usually with radiofrequency or microwave energy. It makes cancer cells more sensitive to radiotherapy and chemotherapy and is therefore applied together with these treatments.
Yes. The HYPERcollar3D, developed by Maarten Paulides and colleagues, enables deep hyperthermia in the head and neck and has been in clinical use at Erasmus MC since 2015. Patient-specific treatment planning is used to focus the heat on the tumour while protecting critical tissues.
In MR-guided hyperthermia, the patient is heated inside an MRI scanner so that the temperature can be measured non-invasively in 3D during treatment (MR thermometry). This allows the heating to be adapted to the individual patient.
Maarten Paulides is an engineer and does not treat patients. Questions about treatment should go to the treating physician or the Hyperthermia Unit of the Erasmus MC Cancer Institute. See the information for patients (Dutch).
Computational Medicine Medical Imaging Implementation & Innovation Voor patiënten (NL)