Comparison of magnetic nanoparticle and microwave hyperthermia cancer treatment methodology and treatment effect in a rodent breast cancer model

Abstract

Purpose The purpose of this study was to compare the efficacy of iron oxide/magnetic nanoparticle hyperthermia (mNPH) and 915 MHz microwave hyperthermia at the same thermal dose in mouse mammary adenocarcinoma model. Materials and Methods A thermal dose equivalent to 60 minutes at 43°C (CEM 60) was delivered to a syngeneic mouse mammary adenocarcinoma flank tumor (MTGB) via mNPH or locally delivered 915 MHz microwaves. mNPH was generated with ferromagnetic, hydroxyethyl starch coated magnetic nanoparticles. Following mNP delivery, the mouse/tumor was exposed to an alternating magnetic field (AMF). The microwave hyperthermia treatment was delivered by a 915 MHz microwave surface applicator. Time required for the tumor to reach three times the treatment volume was used as the primary study endpoint. Acute pathological effects of the treatments were determined using conventional histopathological techniques. Results Locally delivered mNPH resulted in a modest improvement in treatment efficacy as compared to microwave hyperthermia (p=0.09) when prescribed to the same thermal dose. Tumors treated with mNPH also demonstrated reduced peritumoral normal tissue damage. Conclusions Our results demonstrate similar tumor treatment efficacy when tumor heating is delivered by locally delivered mNPs and 915 MHz microwaves at the same measured thermal dose. However, mNPH treatments did not result in the same type or level of peritumoral damage seen with the microwave hyperthermia treatments. These data suggest that mNP hyperthermia is capable of improving the therapeutic ratio for locally delivered tumor hyperthermia. These results further indicate that this improvement is due to improved heat localization in the tumor.

Local hyperthermia treatment of tumors induces CD8+ T cell-mediated resistance against distal and secondary tumors

“…Compared to traditional methods of inducing local hyperthermia, such as inserting a metal antenna into tumors and applying a radiofrequency electromagnetic field(20), combinatorial use of metallic nanoparticles and appropriate external energy sources has better potential to heat tumors uniformly at a given temperature for a desired time(21) as we also confirm here, which makes the method attractive for inducing temperature-dependent effects. Melanoma, despite the feasibility of surgery, is still a life-threatening disease due to its highly metastatic tendency.…”

Magnetic nanoparticles with high specific absorption rate of electromagnetic energy at low field strength for hyperthermia therapy

“…2 In a clinical setting, hyperthermia is predominantly used in conjunction with other forms of cancer therapy, such as radiation therapy and chemotherapy. [3][4][5][6] Magnetic nanoparticle (MNP) hyperthermia as a cancer therapy operates on the principle that magnetic nanoparticles introduced into a tumor produce heat when subjected to an alternating magnetic field (AMF). There are a number of MNPs with different shapes and magnetic properties for Hyperthermia applications.…”

Comparative Study of Extracellular and Intracellular Magnetic Hyperthermia Treatments Using Magnetic Particle Imaging

“…MHT can selectively heat tumor cells without damaging normal tissues [2], unlike conventional hyperthermia treatments such as radiofrequency (RF)-capacitive heating [3]. In order to enhance the therapeutic effect of MHT, it is necessary to deliver and accumulate as many MNPs as possible into the tumor tissues [4] [5].…”