Three-Dimensional Dosimetry for Radiation Safety Estimates from Intrathecal Administration
| Autor: | P. David Mozley, Susan D. Kost, Howard Dobson, Ajay Verma, Jacob Hesterman, Robert W. Holt |
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| Rok vydání: | 2017 |
| Předmět: |
Adult
Male Radiation Intrathecal Three dimensional dosimetry Effective dose (radiation) Imaging phantom 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Medicine Dosimetry Humans Radiology Nuclear Medicine and imaging Internal dosimetry Radiometry Injections Spinal business.industry Phantoms Imaging Torso Absorbed dose Female Safety business Nuclear medicine Monte Carlo Method 030217 neurology & neurosurgery |
| Zdroj: | Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 58(10) |
| ISSN: | 1535-5667 |
| Popis: | Intrathecal administration is of growing interest for drug delivery, and its utility is being increasingly investigated through imaging. In this work, the 3-dimensional Voxel-Based Internal Dosimetry Application (VIDA) and 4D Extended Cardiac Torso Phantom (XCAT) were extended to provide radiation safety estimates specific to intrathecal administration. Methods: The 3-dimensional VIDA dosimetry application Monte Carlo simulation was run using a modified XCAT phantom with additional and edited cerebrospinal fluid (CSF) regions to produce voxel-level absorbed dose per unit cumulated activity maps for 9 selected source regions. Simulation validation was performed to compare absorbed dose estimates for common organs in a preexisting dosimetry tool (OLINDA/EXM). Dynamic planar imaging data were acquired in 6 healthy subjects using administered volumes of 5 or 15 mL (n = 3 each) of 185 MBq of 99mTc-diethylenetriaminepentaacetic acid. Absorbed dose was estimated for each subject using the intrathecal-specific dosimetry application. Results: Simulation results were within 6% of OLINDA estimates for common organs. Absorbed dose estimates were highest (0.3-0.8 mGy/MBq) in the lumbar CSF space. A whole-body effective dose estimate of 0.003 mSv/MBq was observed. An administered volume dependency was observed with a 15-mL volume, resulting in lower absorbed dose estimates for several intrathecal and nonintrathecal regions. Conclusion: The intrathecal-specific VIDA implementation enables tailored dosimetry estimation for regions most relevant in intrathecal administration. Absorbed doses are highly localized to CSF and spinal regions and should be taken into consideration when designing intrathecal imaging studies. A potentially interesting relationship was observed between absorbed dose and administered volume, which merits further investigation. |
| Databáze: | OpenAIRE |
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