Systematic review of the registered clinical trials for oncological hyperthermia treatment.

Background: The use of heat to treat various diseases is called hyperthermia treatment (HT). Since the 1970s, the anti-cancer effects of HT have been investigated. Different HT techniques can be categorized as local, regional and whole-body hyperthermia treatment (WBHT). We aim to provide a summary of recent research done on HT to treat cancer.

Methods: In July 2020 ClinicalTrials.gov were systematically searched for all trials including hyperthermia and cancer registered between 2000 and 2020. Studies were excluded when they did not concern hyperthermal treatment, when they were not oncological studies, when they were observational or other non-interventional studies.

Results: Of 1654 identified trials, 235 were included. Of these 235 studies, 123 described the use of HIPEC (52.3%), 44 other types of regional HT (18.7%), 45 local HT (19.1%) and 15 WBHT (6.4%). A steady increase (720%) in research to hyperthermic intraperitoneal chemotherapy (HIPEC) can be observed in the last decade. Although HIPEC is the most researched HT modality, an evolution in other HT technologies could be observed during the past decade.

Conclusions: Research to HT to treat cancer has expanded fast. Some techniques, for example HIPEC start to be used outside of research context, but overall, more research is needed to establish a clear effect of these HT techniques.