Friday, June 24, 2016

Combined Hyperthermia and Photodynamic Therapy Using a Sub-THz Gyrotron as a Radiation Source


Some researcher may think that using a gyrotron for DNP-NMR spectroscopy seems to be a very exotic application. This article describes another application that is up to now rather unusual - heating up cancer tissue for cancer treatment.




Miyoshi, N., et al., Combined Hyperthermia and Photodynamic Therapy Using a Sub-THz Gyrotron as a Radiation Source. J Infrared Milli Terahz Waves, 2016: p. 1-10.


In this paper, we present results of a hyperthermia treatment of malignant tumors using a gyrotron as a radiation source for heating of the cancerous tissue. They clearly demonstrate the efficiency of the irradiation by sub-THz waves, which leads to steady decrease of the volume of the tumor and finally to its disappearance. A combination of hyperthermia and photodynamic therapy (PDT) that utilizes a novel multifunctional photosensitizer has also been explored. In the latter case, the results are even more convincing and promising. In particular, while after a hyperthermia treatment sometimes a regrowth of the tumor is being observed, in the case of combined hyperthermia and PDT such regrowth has never been noticed. Another combined therapy is based on a preheating of the tumor by gyrotron radiation to temperatures lower than the hyperthermia temperature of 43 °C and followed then by PDT. The results show that such combination significantly increases the efficiency of the treatment. We consider this phenomenon as a synergy effect since it is absent when hyperthermia and PDT are applied separately, and manifests itself only when both methods are combined.