Loading...
Please wait, while we are loading the content...
Similar Documents
Magnetic resonance safety and compatibility of tantalum markers used in proton beam therapy for intraocular tumors: A 7.0 Tesla study.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Oberacker, Eva Paul, Katharina Huelnhagen, Till Oezerdem, Celal Winter, Lukas Pohlmann, Andreas Dipl.-Ing. Boehmert, Laura Stachs, Oliver Heufelder, Jens Weber, Andreas B. Rehák, Matúš Seibel, Ira Niendorf, Thoralf |
| Copyright Year | 2017 |
| Abstract | PURPOSE Proton radiation therapy (PRT) is a standard treatment of uveal melanoma. PRT patients undergo implantation of ocular tantalum markers (OTMs) for treatment planning. Ultra-high-field MRI is a promising technique for 3D tumor visualization and PRT planning. This work examines MR safety and compatibility of OTMs at 7.0 Tesla. METHODS MR safety assessment included deflection angle measurements (DAMs), electromagnetic field (EMF) simulations for specific absorption rate (SAR) estimation, and temperature simulations for examining radiofrequency heating using a bow-tie dipole antenna for transmission. MR compatibility was assessed by susceptibility artifacts in agarose, ex vivo pig eyes, and in an ex vivo tumor eye using gradient echo and fast spin-echo imaging. RESULTS DAM (α < 1 °) demonstrated no risk attributed to magnetically induced OTM deflection. EMF simulations showed that an OTM can be approximated by a disk, demonstrated the need for averaging masses of mave = 0.01 g to accommodate the OTM, and provided SAR0.01g,maximum = 2.64 W/kg (Pin = 1W) in OTM presence. A transfer function was derived, enabling SAR0.01g estimation for individual patient scenarios without the OTM being integrated. Thermal simulations revealed minor OTM-related temperature increase (δT < 15 mK). Susceptibility artifact size (<8 mm) and location suggest no restrictions for MRI of the nervus opticus. CONCLUSION OTMs are not a per se contraindication for MRI. Magn Reson Med 78:1533-1546, 2017. © 2016 International Society for Magnetic Resonance in Medicine. |
| Starting Page | 1533 |
| Ending Page | 1546 |
| Page Count | 14 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://edoc.mdc-berlin.de/16142/1/16142oa.pdf |
| PubMed reference number | 27851881v1 |
| Alternate Webpage(s) | https://doi.org/10.1002/mrm.26534 |
| DOI | 10.1002/mrm.26534 |
| Journal | Magnetic resonance in medicine |
| Volume Number | 78 |
| Issue Number | 4 |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Antenna Device Component CLDN11 gene Electromagnetic Fields Eye Neoplasms Fever Fungal eye infections Glaucoma, Open-Angle Gradient Heating Magnetic Resonance Imaging Medical Device Incompatibility Problem Morphologic artifacts Neuroectodermal Tumor, Primitive Optic Nerve Paraneoplastic Syndromes, Ocular Patients Proton Therapy Protons Tantalum Tesla - unit Therapeutic radiology procedure Uveal melanoma doxorubicin/etoposide/mitotane/vincristine radiofrequency |
| Content Type | Text |
| Resource Type | Article |
