RF Heating of Pancreatic Tumours Guided by Hyperthermia Treatment Planning and Limited Thermometry

Hyperthermia (i.e. heating tumour tissue to 39-43°C) is an oncological treatment to enhance the effect of radiotherapy and chemotherapy. RF heating of deep-seated tumours is performed using phased array systems. Antenna settings are usually determined based on clinical experience, assisted by E-field and temperature measurements in natural body cavities (e.g. cervix, bladder, rectum) adjacent to the tumour. When the tumour is not in the direct vicinity of a natural body cavity, e.g. pancreatic tumours, these probes cannot be positioned easily and adequate thermometry is very limited. Treatment planning can be helpful in addition to the limited thermometry available. The usefulness of treatment guidance by hyperthermia treatment planning and limited thermometry was evaluated for RF heating of two pancreatic cancer patients. Median temperatures measured in the duodenum were above 40°C for patient 1 and above 39°C for patient 2. This demonstrates that treatment planning is helpful to determine antenna settings for adequate hyperthermia treatments with limited thermometry.