RT journal article
T1 In silico assessment of collateral eddy current heating in biocompatible implants subjected to magnetic hyperthermia treatments
A1 Rubia-Rodríguez, Irene
A1 Zilberti, Luca
A1 Arduino, Alessandro
A1 Bottauscio, Oriano
A1 Chiampi, Mario
A1 Ortega Ponce, Daniel
A2 Física de la Materia Condensada
AB Purpose: Bearing partially or fully metallic passive implants represents an exclusion criterion forpatients undergoing a magnetic hyperthermia procedure, but there are no specific studies backingthis restrictive decision. This work assesses how the secondary magnetic field generated at the surfaceof two common types of prostheses affects the safety and efficiency of magnetic hyperthermia treatmentsof localized tumors. The paper also proposes the combination of a multi-criteria decision analysisand a graphical representation of calculated data as an initial screening during the preclinical riskassessment for each patient.Materials and methods: Heating of a hip joint and a dental implant during the treatment ofprostate, colorectal and head and neck tumors have been assessed considering different externalfield conditions and exposure times. The Maxwell equations including the secondary fieldproduced by metallic prostheses have been solved numerically in a discretized computablehuman model. The heat exchange problem has been solved through a modified version of thePennes’ bioheat equation assuming a temperature dependency of blood perfusion and metabolicheat, i.e. thermorregulation. The degree of risk has been assessed using a risk index withparameters coming from custom graphs plotting the specific absorption rate (SAR) vs temperatureincrease, and coefficients derived from a multi-criteria decision analysis performed followingthe MACBETH approach.Results: The comparison of two common biomaterials for passive implants - Ti6Al4V and CoCrMo- shows that both specific absorption rate (SAR) and local temperature increase are found to behigher for the hip prosthesis made by Ti6Al4V despite its lower electrical and thermal conductivity.By tracking the time evolution of temperature upon field application, it has been establishedthat there is a 30 s delay between the time point for which the thermal equilibrium is reached atprostheses and tissues. Likewise, damage may appear in those tissues adjacent to the prosthesesat initial stages of treatment, since recommended thermal thresholds are soon surpassed forhigher field intensities. However, it has also been found that under some operational conditionsthe typical safety rule of staying below or attain a maximum temperature increase or SAR valueis met.Conclusion: The current exclusion criterion for implant-bearing patients in magnetic hyperthermiashould be revised, since it may be too restrictive for a range of the typical field conditions used.Systematic in silico treatment planning using the proposed methodology after a well-focuseddiagnostic
PB TAYLOR & FRANCIS LTD
SN 0265-6736
YR 2021
FD 2021-01
LK http://hdl.handle.net/10498/25212
UL http://hdl.handle.net/10498/25212
LA eng
NO This work has been supported by the NoCanTher project, which has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No [685795]. The authors acknowledge support from the COST Association through the COST actions `RADIOMAG' [TD1402] and `MyWAVE' [CA17115]. D.O. and I.R.R. acknowledge financial support from the Community of Madrid under Contract No. [PEJD-2017-PRE/IND-3663], from the Error! Hyperlink reference not valid. through the Ramon y Cajal grant [RYC2018-025253-I] and Research Networks [RED2018-102626-Hiroshima], as well as the Ministry of Economy and Competitiveness through the grants [MAT2017-85617R] and the `Severo Ochoa' Program for Centers of Excellence in R&D [SEV-2016-0686]. We gratefully acknowledge the support of NVIDIA Corporation through the GPU Grant Program with the donation of the Quadro P6000 GPU used for this research. D. O. acknowledges support from the Programme for the Promotion and Encouragement of Research and Transfer activities at the University of Cadiz.
DS Repositorio Institucional de la Universidad de Cádiz
RD 10-nov-2026