Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Pauritsch, C.
Evaluation of Interface between Tumor Endoprostheses and Magnetic Resonance Fields
Humanmedizin; [ Diplomarbeit ] Medizinische Universität Graz; 2023. pp.
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Bergovec Marko
- Leithner Andreas
- Altmetrics:
- Abstract:
- Primary malignant bone tumors are relatively rare entities with only around 8-9 cases per million per year.1 However, bones are not only affected by primary tumors but additionally are a frequent site for metastatic disease from other malignant tumor entities like prostate, breast or lung cancer.2 The treatment of patients being affected by either primary malignant bone tumors or metastatic disease is not easy and calls for a multidisciplinary approach consisting of systemic chemotherapy, radiotherapy as well as local surgical therapy. For malignant primary bone tumors as well as some secondary tumors, local therapy is done by wide resection of the tumor with consecutive reconstruction of the bone and adjacent joints. In most cases, the reconstruction is done by using a special tumor endoprosthesis, often called megaprosthesis. Patients undergoing this procedure are subject to stringed follow-up regiments of clinical and radiological examinations using X-ray, computer tomography (CT) or magnetic resonance imaging (MRI). During MRI, patients are exposed to strong and rapidly changing magnetic fields. As implanted tumor endoprostheses are large and heavy metallic objects, interactions with the magnetic fields are to be expected. It is currently unknown if tumor endoprostheses are safe for the patient in the MRI environment. This study consists of several parts: The implantation of a tumor endoprosthesis in a cadaveric leg with the recording of the temperature changes caused by the procedure, the subsequent imaging of said cadaveric leg using MRI and observation of temperature differences, measuring the temperature changes of the endoprosthesis during MRI procedures in a phantom as well as performing static tests to measure the displacement force exerted during MRI. Our tests showed increases in temperature up to 80° C during the implantation process. The subsequent testing using the cadaver legs during MRI procedures did not show any clinically relevant increases in temperature. The phantom tests showed clinically irrelevant values for both, displacement force as well as radiofrequency induced heating effects. The findings of this study suggest that patients who have undergone implantation of one of the tested distal femur tumor endoprostheses may be admitted to MRI without being at risk of danger due the interface between the tumor endoprosthesis and the magnetic fields during this procedure.