Practical calibration curve of small-type optically stimulated luminescence (OSL) dosimeter for evaluation of entrance skin dose in the diagnostic X-ray region

Takegami, Kazuki; Hayashi, Hiroaki; Okino, Hiroyuki; Kimoto, Natsumi; Maehata, Itsumi; Kanazawa, Yuki; Okazaki, Toshiya; Kobayashi, Ichiro

doi:10.1007/s12194-015-0318-1

Cited by 32 publications

(19 citation statements)

References 19 publications

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“…We used optically stimulated luminescence (OSL) dosimeters (NanoDot, Landauer, Inc., Glenwood, IL) [19][20][21] (Fig. 1).…”

Section: Dosimetrymentioning

confidence: 99%

“…However, because the mixing ratio of direct and scattered X-rays differs depending on the organ placement under the usage conditions in this study, it is difficult to determine the effective energy of the X-ray field inside the human body exactly. According to the previous research 19 , it has shown that the uncertainty is at most 15% when the manufacturer-determined calibration factor is used to analyze doses using X-rays at other tube voltages. Furthermore, a study has been reported in which the dose determined by the OSL dosimeter using this method shows the correct entrance surface dose during CT examination within the margin of error 20 .…”

Section: Dosimetrymentioning

confidence: 99%

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Direct measurement of radiation exposure dose to individual organs during diagnostic computed tomography examination

Yamashita

Higashino

Hayashi

et al. 2021

Sci Rep

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Ionizing radiation from Computed tomography (CT) examinations and the associated health risks are growing concerns. The purpose of this study was to directly measure individual organ doses during routine clinical CT scanning protocols and to evaluate how these measurements vary with scanning conditions. Optically stimulated luminescence (OSL) dosimeters were surgically implanted into individual organs of fresh non-embalmed whole-body cadavers. Whole-body, head, chest, and abdomen CT scans were taken of 6 cadavers by simulating common clinical methods. The dosimeters were extracted and the radiation exposure doses for each organ were calculated. Average values were used for analysis. Measured individual organ doses for whole-body routine CT protocol were less than 20 mGy for all organs. The measured doses of surface/shallow organs were higher than those of deep organs under the same irradiation conditions. At the same tube voltage and tube current, all internal organ doses were significantly higher for whole-body scans compared with abdominal scans. This study could provide valuable information on individual organ doses and their trends under various scanning conditions. These data could be referenced and used when considering CT examination in daily clinical situations.

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“…We used optically stimulated luminescence (OSL) dosimeters (NanoDot, Landauer, Inc., Glenwood, IL) [19][20][21] (Fig. 1).…”

Section: Dosimetrymentioning

confidence: 99%

Section: Dosimetrymentioning

confidence: 99%

Direct measurement of radiation exposure dose to individual organs during diagnostic computed tomography examination

Yamashita

Higashino

Hayashi

et al. 2021

Sci Rep

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“…Reports concerning thermo‐luminescent dosimeters, 26 alanine/electron spin resonance (ESR) dosimeters, 27 and optically stimulated luminescence (OSL) dosimeters 25,28–35 have been published. In this study, we focused our attention on the OSL dosimeter, which is composed of Al 2 O 3 :C, because this dosimeter has good characteristics for dosimetry in the medical field 31,36,37 . Currently, a commercial OSL dosimeter, named nanoDot TM OSL dosimeter, is being used for medical applications 29 .…”

Section: Introductionmentioning

confidence: 99%

A disposable OSL dosimeter for in vivo measurement of rectum dose during brachytherapy

et al. 2021

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Purpose We aimed to develop a disposable rectum dosimeter and to demonstrate its ability to measure exposure dose to the rectum during brachytherapy for cervical cancer treatment using high‐dose rate 192Ir. Our rectum dosimeter measures the dose with an optically stimulated luminescence (OSL) sheet which was furled to a catheter. The catheter we used is 6 mm in diameter; therefore, it is much less invasive than other rectum dosimeters. The rectum dosimeter developed in this study has the characteristics of being inexpensive and disposable. It is also an easy‐to‐use detector that can be individually sterilized, making it suitable for clinical use. Methods To obtain a dose calibration curve, phantom experiments were performed. Irradiation was performed using a cubical acrylic phantom, and the response of the OSL dosimeter was calibrated with the calculation value predicted by the treatment planning system (TPS). Additionally, the dependence of catheter angle on the dosimeter position and repeatability were evaluated. We also measured the absorbed dose to the rectum of patients who were undergoing brachytherapy for cervical cancer (n = 64). The doses measured with our dosimeters were compared with the doses calculated by the TPS. In order to examine the causes of large differences between measured and planned doses, we classified the data into common and specific cases when performing this clinical study. For specific cases, the following three categories were considered: (a) patient movement, (b) gas in the vagina and/or rectum, and (c) artifacts in the X‐ray image caused by applicators. Results A dose calibration curve was obtained in the range of 0.1 Gy–10.0 Gy. From the evaluation of the dependence of catheter angle on the dosimeter position and repeatability, we determined that our dosimeter can measure rectum dose with an accuracy of 3.1% (k = 1). In this clinical study, we succeeded in measuring actual doses using our rectum dosimeter. We found that the deviation of the measured dose from the planned dose was derived to be 12.7% (k = 1); this result shows that the clinical study included large elements of uncertainty. The discrepancies were found to be due to patient motion during treatment, applicator movement after planning images were taken, and artifacts in the planning images. Conclusions We present the idea that a minimally invasive rectum dosimeter can be fabricated using an OSL sheet. Our clinical study demonstrates that a rectum dosimeter made from an OSL sheet has sufficient ability to evaluate rectum dose. Using this dosimeter, valuable information concerning organs at risk can be obtained during brachytherapy.

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“…The nanoDot OSL dosimeters are widely used for patient dose measurement in the medical field, and many papers on the basic characteristics of nanoDot OSL dosimeter exposed to less than 10 Gy have been reported [4][5][6]. There are also some literatures concerning the patient dose evaluation during radiation diagnosis [7][8][9]. On the other hand, there are a few papers to study the dose response characteristics of OSL dosimeters exposed to more than 10 Gy [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Dose Response Characteristics of a Small Type Optically Stimulated Luminescence Dosimeter Irradiated with More Than 10 Gy

Okazaki

Hashizume

Hashimoto

et al. 2019

Proceedings of the Second International Symposium on Radiation Detectors and Their Uses (ISRD2018)

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It is expected that optically stimulated luminescence (OSL) dosimeters composed of Al 2 O 3 :C will be used for radiation monitoring of the high dose region in high energy accelerator facilities. The nanoDot, a small type OSL dosimeter, can easily measure absorbed doses and read with a microStar reader, a portable OSL reader. In this study, we evaluated the reliability of nanoDot OSL dosimeters for dose measurements of more than 10 Gy. In the evaluation of the upper dose limit and the uncertainty of measurement, the nanoDot OSL dosimeters were exposed to 60 Co gamma rays of 0.07-2350 Gy. They were read using a microStar with an additional neutral density filter to prevent the saturation of PMT response. Although the response of nanoDot OSL dosimeters was proportional to the absorbed dose below 1 Gy, it showed supra linearity greater than 1 Gy and it saturated approximately at 250 Gy. When the fitting line was made in the dose region of less than 1 Gy, and it was extrapolated up to 250 Gy and large deviations in the response were observed. Therefore, we proposed to use a third-ordered fitting curve, which can reduce the deviations within ± 16.8%. We concluded that the nanoDot OSL dosimeter is capable of measuring absorbed doses of up to 110 Gy by using the proposed fitting curve.

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Practical calibration curve of small-type optically stimulated luminescence (OSL) dosimeter for evaluation of entrance skin dose in the diagnostic X-ray region

Cited by 32 publications

References 19 publications

Direct measurement of radiation exposure dose to individual organs during diagnostic computed tomography examination

Direct measurement of radiation exposure dose to individual organs during diagnostic computed tomography examination

A disposable OSL dosimeter for in vivo measurement of rectum dose during brachytherapy

Evaluation of Dose Response Characteristics of a Small Type Optically Stimulated Luminescence Dosimeter Irradiated with More Than 10 Gy

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