Photodyamic therapy in combination with radio frequency electromagnetic field - mediated hyperthermia on cancer cells

Background: Greater sensitivity of cancer cells upon a combination of hyperthermia (HT) with conventional cancer treatment is known but clinically not widely used yet. However, HT application procedures are becoming more refined and therefore more interesting for clinical applications in the future. In our study, we treated three different cancer cell lines with photodynamic therapy (PDT) in combination with radio frequency electromagnetic field (RF-EMF) - mediated HT. Methods: PDT treatment was performed by using an herbal (hypericin)- and a synthetic photosensitizer (liposomal mTHPC, Foslipos (R)) on prostate carcinoma PC-3, osteosarcoma 143-B Lac-Z and head and neck cancer UMB-SCC 745 cell lines. HT was generated either by a commercially available incubator or by RF-EMF exposure. After these experiments, cell viability was monitored with MTT assays. Results: We observed improved PDT effects in all cell lines by using RF-EMF mediated HT. In addition, we could show that despite the same temperature ramping, pulse modified RF-EMF mediated HT exhibited significantly more impact compared with sinus modified RF-EMF mediated HT or common HT. Conclusion: RF-EMF mediated HT seems to create significant effects for PDT on various cancer cells in vitro, which are worth to be explored in greater detail in the future.