Anti-Tumor Effects of induced hyperthermia using a MgFe204.

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 15591887
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Pediatric surgery
• Research Institution: Ehime University
• Principal Investigator: HORIUCHI Atsushi Ehime University, University Hospital, Instructor, 医学部附属病院, 助手 (10284407)
• Co-Investigator(Kenkyū-buntansha): WATANABE Yuji Ehime University, University Hospital, Lecturer, 医学部附属病院, 講師 (20210958)
• Project Period (FY): 2003 – 2004
• Keywords: hyperthermia / ablation / metallic magnetic materials

Research Abstract

This study aimed to put into practical use tumor ablation therapy employing induction heating that has been unavailable practically because it was difficult to develop a heating apparatus for practical use and there is no heating substance that meets the conditions of biocompatibility and sufficient hyperthermia. Application of induction heating to a MgFe_2O_4 needle, constructed to be placed in the tumor, elevated temperature to 131.3 ± 6.5℃ on average on the needle in dried conditions. Histologically, necrotic areas were limited to about 3 mm, but apoptotic lesions were found at the periphery and Hsp70 was expressed at further outside areas. A MgFe_2O_4 needle was placed in the rat subcutaneous tumor (average diameter, 17.6 mm) and induction heating was applied for 30 min. Temperature rose by 12.3±1.8℃ on the skin surface and 9.6±5.7℃ in the tumor on average, and a remarkable reduction in tumor size was found in 6 of 7 rats (85.7%). The size in liver tumor was also decreasesed in 5/6 rats (83.3%). Taken together, it was presumed that induction heating exerted antitumor effect with a reduction in tumor size, involving the effect other than direct necrotizing effect, since it necrotized relatively small areas.