Sensitivity improvement of optical computed tomography scanners for scanning gel dosimeters
Sensitivity improvement of OCTs for scanning gel dosimeters
Abstract
Despite recent advances in OCT systems, there is skepticism regarding the sensitivity and performance of these systems for gel dosimetry. The optical sensitivity of gel dosimeters changes at different wavelengths and their maximum sensitivities are achieved at the particular wavelengths. Therefore, the optimal wavelength must be used for optical scanning of the gel dosimeters. Since OCT systems are used for scanning different gel dosimeters, a mono-energy light source would not lead to optimal performance. Commercially available multi-wavelength lasers provide a variety of power and wavelength ranges. Adopting multi-wavelength light sources instead of single-wavelength laser sources increases the price of the system by less than 5%, which is justifiable and ignorable due to the considerably increased performance and sensitivity. In the proposed approach, only the wavelength of the scanning beam would be optimized based on the gel dosimeter type. The rules for determining the opacity of the beam path across the sample are the same for all gel dosimeters. Therefore, the change in wavelength of the scanning beam didn’t change the scanning procedure and there is no additional complexity in the OCTs with the multi-wavelength light sources.
2. S Abtahi, M Zahmatkesh, H Khalafi, "Investigation of an improved MAA-based polymer gel for thermal neutron dosimetry." Journal of Radioanalytical and Nuclear Chemistry, Vol. 307(No. 2), p. 855-68, (2016).
3. SS Zakariaee, A Mesbahi, A Keshtkar, V Azimirad, "Design and construction of an optical computed tomography scanner for polymer gel dosimetry application." Journal of Medical Signals and Sensors, Vol. 4(No. 2), p.130-8, (2014).
4. M Oldham, JH Siewerdsen, S Kumar, J Wong, DA Jaffray, "Optical-CT gel-dosimetry I: basic investigations." Medical Physics, Vol. 30(No. 4), p.623-34, (2003).
5. C Baldock, DY De, S Doran, G Ibbott, A Jirasek, M Lepage, et al, "Polymer gel dosimetry." Physics in Medicine & Biology, Vol. 55(No. 5), p.1-63, (2010).
6. SS Zakariaee, M Molazadeh, A Takavar, A Shirazi, A Mesbahi, A Zeinali, "Validation of a prototype optical computed tomography system." Journal of Medical Signals and Sensors, Vol. 5(No. 2), p.123-30, (2015).
7. A Mesbahi, S-S Zakariaee, "Optical characterization of NIPAM and PAGAT polymer gels for radiation dosimetry." Iranian Journal of Medical Physics, Vol. 11(No. 3-4), p.188-94, (2014).
8. S Bosi, P Naseri, A Puran, J Davies, C Baldock, "Initial investigation of a novel light-scattering gel phantom for evaluation of optical CT scanners for radiotherapy gel dosimetry." Physics in Medicine & Biology, Vol. 52, p.2893-903, (2007).
9. A Jirasek, D Rudko, D Wells, "A prototype fan-beam optical CT scanner for polymer gel
dosimetry." 5th International Conference on Radiotherapy Gel Dosimetry (DOSGEL 2008). Journal of Physics: Conference Series, Vol. 164, p.1-6, (2009).
10. PY Guo, JA Adamovics, M Oldham, "Characterization of a new radiochromic three-dimensional dosimeter." Medical Physics, Vol. 33(No. 5), p.1338-45, (2006).
11. M Oldham, JH Siewerdsen, A Shetty, DA Jaffray, "High resolution gel-dosimetry by optical-CT and MR scanning." Medical Physics, Vol. 28(No. 7), p.1436-45, (2001).
12. J Gore, M Ranade, M Maryanski, R Schulz, "Radiation dose distributions in three dimensions from tomographic optical density scanning of polymer gels: I. Development of an optical scanner." Physics in Medicine & Biology, Vol. 41(No. 12), p.2695-704, (1996).
13. M Oldham, "3D dosimetry by optical-CT scanning." Journal of Physics, Vol. 56, p.58-71,(2006).
14. HS Sakhalkar, M Oldham, "Fast, high-resolution 3D dosimetry utilizing a novel optical-CT scanner incorporating tertiary telecentric collimation." Medical Physics, Vol. 35(No. 1), p.101-11, (2008).
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| Issue | Articles in Press | |
| Section | Technical Note | |
| Keywords | ||
| Optical computed tomography Polymer gel dosimetry Multi-wavelength lasers Optical sensitivity of the gel dosimeters. | ||
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