Populariserende Samenvatting Hyperthermia, the process of raising body or tissue temperatures, is gaining attention as a cancer treatment. This method aims to kill or weaken cancer cells, making them more susceptible to conventional therapies such as chemotherapy, radiation, or immunotherapy. A key advantage of hyperthermia is its ability to engage the immune system, activating immune cells (e.g. T-cells and natural killer (NK) cells) to target cancer more effectively, especially in challenging cases like spreading tumors. Hyperthermia can be applied in different ways, each with its strengths and limitations. Local hyperthermia heats solid tumors to induce cell death at 41–45°C or ablation at up to 80°C. Regional hyperthermia treats larger areas, like limbs or the peritoneal cavity, while whole-body hyperthermia addresses metastatic cancer, the spread of cancer to different parts of the body, by raising the body’s temperature to fever-like levels. Since metastatic cancer is one of the most difficult challenges in oncology, the ability of whole-body hyperthermia to boost the immune system’s ability to fight widespread disease holds great promise. When combined with existing treatments, hyperthermia can significantly improve outcomes. By helping the immune system recognize and destroy cancer cells, it can improve survival rates and reduce tumor recurrence. It also enhances the effectiveness of chemotherapy and immunotherapy drugs, such as immune checkpoint inhibitors, by improving their distribution to the tumor site. These methods used alone or alongside other treatments, help the immune system fight cancer. Controlling the temperature during hyperthermia is still a major challenge. Too much heat can harm healthy tissues, while too little may not trigger the desired immune response. Maintaining consistent temperatures in clinical settings can be challenging, leading to an emphasis on milder hyperthermia (39–41°C), which offers a more manageable and stable temperature range. Another limitation is the lack of precise technology to monitor temperature in three dimensions during treatment, which currently relies on one-dimensional thermometry. Better tools and guidelines are needed to standardize treatments. Hyperthermia shows great potential as a complementary cancer therapy. However, more research and technological improvements are necessary to ensure its safe and effective application. With further advancements, hyperthermia could become a vital tool in cancer treatment, improving outcomes while minimizing the side effects associated with conventional therapies. In conclusion, hyperthermia is an innovative approach that strengthens the immune system and enhances the effectiveness of cancer treatments. While promising, its full potential will only be realized through continued research and the development of improved treatment protocols and technologies. Social Impact Cancer is a leading cause of death worldwide, with approximately 18.1 million new cases and 9.6 million deaths reported in 2018 by the World Health Organization. Traditional cancer treatments (such as surgery, chemotherapy, and radiotherapy), while effective, come with significant drawbacks including severe side effects, high recurrence rates, and the risk of incomplete tumor eradication, particularly in metastatic cases. This makes it crucial to explore new methods that can enhance the efficacy of existing treatments while reducing harm to patients. Hyperthermia offers a novel way to target cancer cells by raising tissue temperatures to specific levels that kill or weaken the cancer cells. This method enhances the effectiveness of conventional treatments like chemotherapy, radiation, and immunotherapy by making cancer cells more susceptible to these treatments. This ensures that conventional treatments are worthwhile. As most cancer-related deaths are linked to metastasis, hyperthermia's application in combination with immunotherapy for instance could revolutionize the way advanced-stage cancers are treated, potentially increasing survival rates. Furthermore, hyperthermia also stimulates the immune system which in itself will attack the tumor on its own. In summary, this thesis on hyperthermia therapy contributes valuable insights into a promising area of cancer treatment, with the potential to improve patient outcomes, reduce treatment side effects, and stimulate further innovation in the field of oncology.