Review article: Treating tumoral diseases (cancer) with a combination of ionizing radiation and pulsed electric fields

The aim is to review a patented method and apparatus for treating tumor diseases (cancer) with a combination of ionizing radiation and pulsed electric fields, that might open a new regime of radiation therapy fractionation with a short intensive treatment with high radiation dose fractions combined with pulsed electric fields. Sub-optimal radiation treatment was administered separately or in combination with electric pulses of field strength (1200 V/cm) to subcutaneous implanted rat brain tumors on both hind legs. The treatment was repeated four consecutive days and evaluated by recording tumor growth rate and microscopically examination. Tumors were stained for Factor VIII/von Willebrand Factor to investigate effects on the tumor vasculature and for T-lymphocytes CD4 and CD8 to study their infiltration into the treated tumors. Radiation and pulsed electric fields applied concomitantly resulted in rapid tumor regression with significantly (P<0.01 vs. Control) prolonged survival (tumor free >80 days after treatment) and an average cure rate of 67%. Animals treated with either just radiation or just Pulsed electric fields showed no significant enhanced survival. Histological and immunohistochemical examination of tumors treated with RAD and PEF showed instant and severe deteriorating effects on tumor vasculature and enhanced infiltration of T-lymphocytes.