Iron overload conditions are a prevalent issue in global healthcare that require the accurate monitoring of iron levels to effectively provide treatment. X-ray fluorescence has emerged as a candidate for a point-of-care measurement tool for the detection of trace elements in vivo. This study explores the feasibility of a portable in vivo x-ray fluorescence (IVXRF) instrument using 125I as a point-of-care device in measuring skin iron levels.
The system was calibrated using iron-doped water phantoms for various physiologically-applicable iron concentrations. Measurements were conducted on ex vivo rat skin samples (n = 34), which were then compared to a benchmark laboratory-based XRF system. Monte Carlo modelling using MCNP 6.2 was used to simulate the system in different conditions and provide an estimate of the radiation dose of the system on soft tissue.
The R2 value for the calibration line of iron concentration in ppm to normalized iron signal was determined to be 0.985 (p < 0.01). For a measurement period of 1800 s real-time, the minimum detectable limit (MDL) of the system is 3.86 ± 0.06 ppm of iron. The R2 value for the linear regression between the IVXRF and benchmark XRF system normalized iron signals was 0.731 (p < 0.01). The R2 value for the linear regression between the IVXRF normalized iron signal and sample injected iron dose was 0.719 (p < 0.01), meaning the system can distinguish between different iron levels in rat skin. From the Monte Carlo simulations, the expected effective dose contribution from the IVXRF system is 101.68 ± 0.03 nSv.
The IVXRF system was shown to accurately measure iron concentrations in ex vivo rat skin samples within the iron concentration ranges found within healthy and iron-overloaded patients. Further work shall be conducted to validate the system in in vivo applications. / Thesis / Master of Science (MSc) / Iron overload is a prevalent issue in healthcare, with many individuals experiencing detrimental symptoms, such as organ damage and heart failure. Modern treatment significantly improves quality of life but must be continuously monitored.
This thesis covers the development of a non-invasive, cost-effective, and accurate system that can measure skin iron levels in patients to ensure effective monitoring.
The results from this thesis suggest that the system can be used for clinical use to measure patient skin iron levels. It can theoretically measure iron in patients with normal and elevated iron levels. Simulation work suggests that the system will lead to negligible risk from radiation exposure.
While this thesis and its findings support the feasibility of the system, further work is required before clinical implementation of the device.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/28691 |
| Date | January 2023 |
| Creators | Tang, Bobby |
| Contributors | Farquharson, Michael, McNeill, Fiona, Physics and Astronomy |
| Source Sets | McMaster University |
| Detected Language | English |
| Type | Thesis |
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