Optically stimulated luminescence (OSL) dosimetry in medicine (original) (raw)
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Medical applications of optically stimulated luminescence dosimeters (OSLDs
Radiation Measurements, 2010
This work presents an overview of the advances in the application of optically stimulated luminescence (OSL) to dosimetry in diagnostic radiology and radiation therapy achieved by the Oklahoma State University group in collaboration with the University of Oklahoma Health Sciences Center and the University of Texas M. D. Anderson Cancer Center. This overview discusses: (a) the development and demonstration of readout protocols for high-precision dosimetry in radiation therapy using high-energy photons and electrons; (b) the determination of dose profiles inside acrylic phantom in computed tomography; and (c) the performance of OSL dosimeters for dosimetry of proton therapeutic beams, including point measurements in air and along pristine and spread-out Bragg peaks. Our results demonstrate the capability of performing high-precision measurements (experimental standard deviation of 0.7%) in radiotherapy and show the possibility of performing one-dimensional dose mapping in X-ray computed tomography and proton beams. In the case of protons, our results show that OSL dosimeters are energy independent for protons with energies above 100 MeV, but a reduction in efficiency is observed at the end of the proton range.
Optically stimulated luminescence and its use in medical dosimetry
Radiation Measurements, 2006
The optically stimulated luminescence (OSL) technique has already became a successful tool in personal radiation dosimetry, geological and archeological dating, and in radiation diagnostic imaging. This review briefly describes the history of OSL. Significant advances have been made recently in the theoretical study of OSL to explain the behavior of radiation sensitive materials with several types of dosimetry traps, recombination centers and competing deep traps. Progress in material and detector engineering has allowed new and promising developments regarding OSL applications in the medical field. Special attention is dedicated to Al 2 O 3 :C as a material of choice for many dosimetric applications; present technology can provide Al 2 O 3 :C fiber sensors with diameters as small as 300 m. A new RL/OSL fiberoptic system has a high potential for in vivo and in vitro dosimetry in both radiation therapy and diagnostic mammography. Different aspects of instrumentation, data processing algorithms, post-irradiation and real-time measurements are described.
The contribution of optically stimulated luminescence dosimetry in quality control in radiotherapy
2011
In 2011, Brazil will have more than 489,000 new cases of cancer. Of these patients, a considerable contingent will be submitted to radiotherapy procedures. Thus, efficient systems that guarantee the quality of the beams used in radiotherapy procedures are extremely important because collaborate with the overall success of treatment. This paper presents the use of OSL (optically stimulated luminescence) dosimetry procedures in quality control in radiotherapy, making verification of the symmetry of treatment of radioactive fields emitted by linear accelerators. The use of OSL dosimetry was compared to procedures performed daily, using ionization chambers. Dosimeters of aluminum oxide doped with carbon (Al2O3: C) were distributed on a map, with the delimitation of a field 20x20 cm arranged as follows: one in the center of the field; four equidistant distributed, forming a square 10x10 cm; and 4 remaining distributed equidistant, forming a square of 20x20 cm. This arrangement is similar...
Dentomaxillofacial Radiology, 2012
The aim of this study was to assess the characteristics of an optically stimulated luminescence dosemeter (OSLD) for use in diagnostic radiology and to apply the OSLD in measuring the organ doses by panoramic radiography. Methods: The dose linearity, energy dependency and angular dependency of aluminium oxide-based OSLDs were examined using an X-ray generator to simulate various exposure settings in diagnostic radiology. The organ doses were then measured by inserting the dosemeters into an anthropomorphic phantom while using three panoramic machines. Results: The dosemeters demonstrated consistent dose linearity (coefficient of variation , 1.5%) and no significant energy dependency (coefficient of variation , 1.5%) under the applied exposure conditions. They also exhibited negligible angular dependency (# 10%). The organ doses of the X-ray as a result of panoramic imaging by three machines were calculated using the dosemeters. Conclusion: OSLDs can be utilized to measure the organ doses in diagnostic radiology. The availability of these dosemeters in strip form proves to be reliably advantageous.
Optically Stimulated Luminescent Dosimetry for High Dose Rate Brachytherapy
Frontiers in Oncology, 2012
The objective was to determine whether optically stimulated luminescent dosimeters (OSLDs) were appropriate for in vivo measurements in high dose rate brachytherapy. In order to make this distinction, three dosimetric characteristics were tested: dose linearity, dose rate dependence, and angular dependence. The Landauer nan-oDot™ OSLDs were chosen due to their popularity and their availability commercially. Methods: To test the dose linearity, each OSLD was placed at a constant location and the dwell time was varied. Next, in order to test the dose rate dependence, each OSLD was placed at different OLSD-to-source distances and the dwell time was held constant. A curved geometry was created using a circular Accuboost ® applicator in order to test angular dependence. Results: The OSLD response remained linear for high doses and was independent of dose rate. For doses up to 600 cGy, the linear coefficient of determination was 0.9988 with a response of 725 counts per cGy. The angular dependence was significant only in "edge-on" scenarios. Conclusion: OSLDs are conveniently read out using commercially available readers. OSLDs can be re-read and serve as a permanent record for clinical records or be annealed using conventional fluorescent light. Lastly, OSLDs are produced commercially for $5 each. Due to these convenient features, in conjunction with the dosimetric performance, OSLDs should be considered a clinically feasible and attractive tool for in vivo HDR brachytherapy measurements.