Mitigation of magnetic particle hyperthermia side effects by magnetic field controls
| Autor: | A.R. Tsiapla, Antonia-Areti Kalimeri, Mavroeidis Angelakeris, E. Myrovali, Theodoros Samaras, Nikolaos Maniotis, Orestis Kalogirou |
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| Rok vydání: | 2021 |
| Předmět: |
magnetic nanoparticles
Cancer Research Materials science Field (physics) Physiology Magnetic particle inspection 030218 nuclear medicine & medical imaging law.invention Magnetics 03 medical and health sciences 0302 clinical medicine law Physiology (medical) Electric field Medical technology Eddy current Humans Hyperthermia magnetic hyperthermia R855-855.5 eddy currents Temperature Hyperthermia Induced Mechanics intermittently applied amf Magnetic field Magnetic Fields Magnetic hyperthermia Duty cycle 030220 oncology & carcinogenesis cancer therapy Magnetic nanoparticles |
| Zdroj: | International Journal of Hyperthermia, Vol 38, Iss 1, Pp 511-522 (2021) |
| ISSN: | 1464-5157 0265-6736 |
| Popis: | Objective: In magnetic particle hyperthermia, a promising least-invasive cancer treatment, malignant regions in proximity with magnetic nanoparticles undergo heat stress, while unavoidably surrounding healthy tissues may also suffer from heat either directly or indirectly by the induced eddy currents, due to the developed electric fields as well. Here, we propose a facile upgrade of a typical magnetic particle hyperthermia protocol, to selectively mitigate eddy currents' heating without compromising the beneficial role of heating in malignant regions. Method: The key idea is to apply the external magnetic field intermittently (in an ON/OFF pulse mode), instead of the continuous field mode typically applied. The parameters of the intermittent field mode, such as time intervals (ON time: 25-100 s, OFF time: 50-200 s, Duty Cycle:16-100%) and field amplitude (30-70 mT) are optimized based on evaluation on healthy tissue and cancer tissue phantoms. The goal is to sustain in cancer tissue phantom the maximum temperature increase (preferably within 4-8°C above body temperature of 37°C), while in the healthy tissue phantom temperature variation is suppressed far below the 4°C dictating the eddy current mitigation. Results: Optimum conditions of intermittent field (ON/OFF: 50/100 in s, Duty Cycle: 33%, magnetic field: 45mT) are then examined in ex-vivo samples verifying the successful suppression of eddy currents. Simultaneously, a well-elaborated theoretical approach provides a rapid calculation of temperature increase and, furthermore, the ability to quickly simulate a variety of duty cycle times and field controls may save experimental time. Conclusion: Eventually, the application of an intermittent field mode in a magnetic particle hyperthermia protocol, succeeds in eddy current mitigation in surrounding tissues and allows for the application of larger field amplitudes that may augment hyperthermia efficiency without objecting typical biomedical applicability field constraints such as Brezovich criterion. |
| Databáze: | OpenAIRE |
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