Conclusion
This work presents the first line of handheld medical induction heaters and have the potential to be a complement to existing cancer therapies.Significance:These instruments could enable the development of MFH modalities that will facilitate the clinical translation of this thermal treatment.
Methods
Miniature 'pancake' coils were wound and inserted into 3D printed enclosures. Ovarian (SKOV-3, A2780) and prostate (PC-3, LNCaP) cancer cell lines were used to evaluate the instruments' capabilities in killing cancer cellsin vitro, using Synomag®-D nanoparticles as the heat mediators. NIH3T3 normal cell lines were also used with both devices to observe if these cells tolerated the conditions applied.
Objective
Magnetic fluid hyperthermia (MFH) is a still experimental technique found to have a potential application in the treatment of cancer. The method aims to reach around 41 °C-47 °C in the tumor site by exciting magnetic nanoparticles with an externally applied alternating magnetic field (AMF), where cell death is expected to occur. Applying AMFs with high spatial resolution is still a challenge. The AMFs from current and prospective MFH applicators cover relatively large areas; being not suitable for patients having metallic implants near the treatment area. Thus, there will be a clinical need for smaller magnetic field applicators. To this end, a laparoscopic induction heater (LIH) and a transrectal induction heater (TRIH) were developed.
Results
Magnetic field intensities reached by the LIH and TRIH were 42.6 kA m-1at 326 kHz and 26.3 kA m-1at 303 kHz, respectively. Temperatures reached in the samples were 41 °C by the LIH and 43 °C by the TRIH. Both instruments successfully accomplished killing cancer cells, with minimal effects on normal cells.
Significance
These instruments could enable the development of MFH modalities that will facilitate the clinical translation of this thermal treatment.