Preoperative thermochemotherapy of oral cancer using magnetic induction hyperthermia (Implant Heating System: IHS)

Abstract

Eight patients with primary cancer of the oral cavity were preoperatively treated by combined treatment with hyperthermia and chemotherapy. They received two courses of chemotherapy, which included intra-arterial infusion of 100 mg of cisplatin (CDDP) and 25 mg of peplomycin (PEP) via the superficial temporal artery. The patients also received interstitial hyperthermia for 45 min once a week using the Implant Heating System (IHS) with chemotherapy. IHS consists of ferromagnetic implant, induction coil and generator to produce high frequency magnetic field. The ferromagnetic implant is made of Fe-Pt alloy (Fe: 73%, Pt: 27%), and has a Curie temperature of 68 degrees C. As a result, clinical complete response (CR) was observed in seven patients and partial response (PR) in one, and postoperative pathological examination showed no residual tumour cells in any specimen. Combined interstitial hyperthermia by IHS and chemotherapy is thus found to be an effective therapeutic method for treating oral cancers.

Dependence of the LC Parameter on the Temperature Rise of a Resonant Circuit for Hyperthermia Implant

“…Table I summarizes the characteristics of resonant circuits with various combinations of the inductor and the capacitor. It is noted that a lower residual resistance and a larger electromotive force of the inductor are essential for a higher temperature rise of the circuits from the maximum consumed power described in (1). A larger electromotive force is induced in a coil of larger inductance.…”

“…It has been known that the survival rate of cancer cells drops sharply at 42.5 • C. In addition, the temperature of the cancerous tissue rises more easily than that of normal tissues because of poor cooling by a sluggish blood flow. Hyperthermia elevates the local temperature above 42.5 • C to kill cancer cells, whereas most of the surrounding normal tissues are not damaged at the temperatures below 44 • C. The hyperthermia using implants has been reported in terms of its ability to control the temperature of cancerous tissues, and a possibility to warm them locally [1,2]. A resonant circuit, which is heated efficiently by an external magnetic field, is one of the candidates for the implants [3].…”

Local hyperthermia in head and neck cancer: mechanism, application and advance

“…And, hyperthermia combined with chemotherapy also has bettered clinical response for patients with head and neck cancers. Tohnai et al [ 55 , 56 ] reported that eight patients with primary cancer of the oral cavity were preoperatively treated by combined treatment with hyperthermia and chemotherapy. As a result, CR was observed in seven patients and partial response (PR) in one, and postoperative pathological examination showed no residual tumor cells in any specimen.…”

A Possibility of Hyperthermia Treatment using MRI Equipment

“…The implants of tiny elements inside of the body are heated up by an external energy source. A combination of magnetic materials as the implants and a magnetic field applied from outside of the body has attracted much attention [1,2]. Recently fundamental research using magnetic nanoparticles has been also popular [3].…”