Herrero de la Parte Borja, Rodrigo Irati, Gutiérrez-Basoa Jon, Iturrizaga Correcher Sira, Mar Medina Carmen, Echevarría-Uraga Jose Javier, Garcia Jose Angel, Plazaola Fernando, García-Alonso Ignacio
Department of Surgery and Radiology and Physical Medicine, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, ES48940 Leioa, Spain.
Interventional Radiology Research Group, Biocruces Bizkaia Health Research Institute, ES48903 Barakaldo, Spain.
Cancers (Basel). 2022 Jun 23;14(13):3084. doi: 10.3390/cancers14133084.
Lately, major advances in crucial aspects of magnetic hyperthermia (MH) therapy have been made (nanoparticle synthesis, biosafety, etc.). However, there is one key point still lacking improvement: the magnetic field-frequency product ( = 4.85 × 10 Ams) proposed by Atkinson-Brezovich as a limit for MH therapies. Herein, we analyze both local and systemic physiological effects of overpassing this limit.
Different combinations of field frequency and intensity exceeding the Atkinson-Brezovich limit (591-920 kHz, and 10.3-18 kA/m) have been applied for 21 min to WAG/RijHsd male rats, randomly distributed to groups of 12 animals; half of them were sacrificed after 12 h, and the others 10 days later. Biochemical serum analyses were performed to assess the general, hepatic, renal and/or pancreatic function.
MH raised liver temperature to 42.8 ± 0.4 °C. Although in five of the groups the exposure was relatively well tolerated, in the two of highest frequency (928 kHz) and intensity (18 kA/m), more than 50% of the animals died. A striking elevation in liver and systemic markers was observed after 12 h in the surviving animals, independently of the frequency and intensity used. Ten days later, liver markers were almost recovered in all of the animals. However, in those groups exposed to 591 kHz and 16 kA/m, and 700 kHz and 13.7 kA/m systemic markers remained altered.
Exceeding the Atkinson-Brezovich limit up to 9.59 × 10 Ams seems to be safe, though further research is needed to understand the impact of intensity and/or frequency on physiological conditions following MH.
最近，磁热疗（MH）治疗的关键方面（纳米颗粒合成、生物安全性等）取得了重大进展。然而，仍有一个关键点有待改进：阿特金森 - 布雷佐维奇提出的作为MH治疗极限的磁场 - 频率乘积（= 4.85×10 Ams）。在此，我们分析超过此极限的局部和全身生理效应。
将超过阿特金森 - 布雷佐维奇极限（591 - 920 kHz，10.3 - 18 kA/m）的不同场频和强度组合应用于WAG/RijHsd雄性大鼠21分钟，随机分为每组12只动物的组；其中一半在12小时后处死，另一半在10天后处死。进行生化血清分析以评估总体、肝脏、肾脏和/或胰腺功能。
磁热疗将肝脏温度升高至42.8±0.4°C。虽然在五组中暴露相对耐受良好，但在两个最高频率（928 kHz）和强度（18 kA/m）的组中，超过50%的动物死亡。在存活的动物中，12小时后观察到肝脏和全身标志物显著升高，与所用的频率和强度无关。10天后，所有动物的肝脏标志物几乎恢复。然而，在暴露于591 kHz和16 kA/m以及700 kHz和13.7 kA/m的组中，全身标志物仍然异常。
超过阿特金森 - 布雷佐维奇极限至9.59×10 Ams似乎是安全的，不过需要进一步研究以了解磁热疗后强度和/或频率对生理状况的影响。
