Solid‐state dosimeters: A new approach for mammography measurements

Brateman, Libby; Heintz, Philip H.

doi:10.1118/1.4903263

Cited by 12 publications

(6 citation statements)

References 3 publications

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“…The selection of the tested dosimeters was made based on the limited information from the calibration laboratories in order to cover some of the most common models. This selection is comparable with the study of Brateman and Heintz and includes dosimeters that have been marketed for a long time as well as more recent models.…”

Section: Discussionmentioning

confidence: 70%

“…With increased dose rate, X2 measured the tube voltage for Mo‐Rh 30 and 35, but still failed for Mo‐Rh 28. The performance of tube voltage measurement of semiconductor dosimeters on clinical mammography units was investigated by Brateman and Heintz . There, Xi also failed to derive tube voltage from measurements for W‐Ag on the clinical mammography units.…”

Section: Discussionmentioning

confidence: 99%

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Performance of semiconductor dosimeters with a range of radiation qualities used for mammography: A calibration laboratory study

et al. 2020

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Purpose To investigate the radiation quality dependence of the response of commercial semiconductor‐based dosimeters, and to estimate potential errors and uncertainties related to different measurement and calibration scenarios. Methods All measurement results were compared to reference values measured at the IAEA dosimetry laboratory which is traceable to the international system of units (SI). Energy dependence of the response of eight semiconductor dosimeters were determined for five different anode‐filter combinations and tube voltages from 25 to 35 kV. For systems capable of deriving half value layer (HVL) and tube voltage from measurements, calibration coefficients for these measurements were calculated. Results For six dosimeters, the maximum deviations from the reference value of the air kerma measurement were within ±5% as required by IEC 61674. Calibration coefficients for radiation qualities (anode‐filter and tube voltage combinations) relative to reference radiation quality Mo‐Mo 28 kV deviate up to 12%. HVL and tube voltage measurements exhibited deviations up to 11% and 10%, respectively. Conclusions The air kerma responses of modern semiconductor dosimeters have a small energy dependence. However, no dosimeter tested complied with the accuracy limits stated by the manufacturer for tube voltage measurements, and only two dosimeters complied with the limits for HVL measurements. Absolute measurement of HVL and tube voltage with semiconductor dosimeters have to be verified for actual clinical radiation conditions on clinical mammography systems. Semiconductor dosimeters can be used for quality control measurements if individual calibration coefficients are available for the radiation condition applied. If other conditions are applied, additional uncertainty needs to be considered, particularly in the case of HVL and tube voltage measurements.

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Section: Discussionmentioning

confidence: 70%

Section: Discussionmentioning

confidence: 99%

Performance of semiconductor dosimeters with a range of radiation qualities used for mammography: A calibration laboratory study

et al. 2020

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“…This detector is generally designed for diagnostic radiography (13) . The source‐to‐detector distance (SDD) was 226.4 cm, and the detector‐to‐imager distance (DID) was 236.8 cm.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of a combined respiratory‐gating system comprising the TrueBeam linear accelerator and a new real‐time tumor‐tracking radiotherapy system: a preliminary study

Shiinoki

Kawamura

Uehara

et al. 2016

J Applied Clin Med Phys

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A combined system comprising the TrueBeam linear accelerator and a new real‐time, tumor‐tracking radiotherapy system, SyncTraX, was installed in our institution. The goals of this study were to assess the capability of SyncTraX in measuring the position of a fiducial marker using color fluoroscopic images, and to evaluate the dosimetric and geometric accuracy of respiratory‐gated radiotherapy using this combined system for the simple geometry. For the fundamental evaluation of respiratory‐gated radiotherapy using SyncTraX, the following were performed: 1) determination of dosimetric and positional characteristics of sinusoidal patterns using a motor‐driven base for several gating windows; 2) measurement of time delay using an oscilloscope; 3) positional verification of sinusoidal patterns and the pattern in the case of a lung cancer patient; 4) measurement of the half‐value layer (HVL in mm AL), effective kVp, and air kerma, using a solid‐state detector for each fluoroscopic condition, to determine the patient dose. The dose profile in a moving phantom with gated radiotherapy having a gating window ≤4 mm was in good agreement with that under static conditions for each photon beam. The total time delay between TrueBeam and SyncTraX was <227 ms for each photon beam. The mean of the positional tracking error was <0.4 mm for sinusoidal patterns and for the pattern in the case of a lung cancer patient. The air‐kerma rates from one fluoroscopy direction were 1.93±0.01, 2.86±0.01, 3.92±0.04, 5.28±0.03, and 6.60±0.05 mGy/min for 70, 80, 90, 100, and 110 kV X‐ray beams at 80 mA, respectively. The combined system comprising TrueBeam and SyncTraX could track the motion of the fiducial marker and control radiation delivery with reasonable accuracy; therefore, this system provides significant dosimetric improvement. However, patient exposure dose from fluoroscopy was not clinically negligible.PACS number(s): 87.53.Bn, 87.55.km, 87.55.Qr

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“…Currently, a variety of semiconductor dosimeters are commercially available. In the literature, the results for the ionisation chamber and semiconductor dosimeter show differences ranging from 4.3% to 13.4%, depending on the type of semiconductor detector used for the MGD [19]. Therefore, an HD-M can provide accurate measurements similar to commercial products that are in the range of the measuring tube voltage (24 kV to 32 kV) with Mo-Mo target filter.…”

Section: Energy Characteristicsmentioning

confidence: 99%

“…In recent years, there have been many reports that semiconductor dosimeters are useful in daily QC during general imaging [11,[15][16][17][18]. However, in the case of semiconductor dosimeters, the response varies depending on the energy of the x-rays [19]. For mammography, there are many reports that have indicated that the response changes significantly owing to differences in x-ray energy, and that the target-filter combination is limited [19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Characteristic evaluation of a simple hand-made semiconductor dosimeter for mammography

Erika¹,

Yamashita²,

Sato³

2021

J. Radiol. Prot.

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Daily quality control of mammography equipment is important for providing optimal images and determining appropriate doses. To popularise dosimeters, the Measurement Division, the Japanese Society of Radiological Technology hold a seminar on making simple dosimeters. At this seminar, a hand-made dosimeter for mammography (HD-M) can be made at low cost. However, HD-Ms employ semiconductors, and their energy responses are subject to significant variations. This investigation involved the determination of precautions when using HD-Ms, examining their energy response characteristics and measurable energy ranges. HD-M has four types of selectors for response correction. When the selector and the tube voltage were equal, the HD-M readings matched that of the ionisation chamber within 5%. However, in case of target filter combinations and measuring tube voltages that the selector does not support, the HD-M readings differed by up to 53% from the ionisation chamber values. HD-M may use different measurement circuits and semiconductor elements depending on the time of the seminar. In this study, it was clarified that the correction factor k, which is the average value of the ratio of the measured value of the ionisation chamber dosimeter to the measured value of HD-M, changes from 0.62 to 1.53 depending on irradiation conditions such as the combination of target filters and the tube voltage. It was demonstrated that HD-M functions sufficiently as a dosimeter for daily management by determining the correction factor using the method proposed in this study.

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Solid‐state dosimeters: A new approach for mammography measurements

Cited by 12 publications

References 3 publications

Performance of semiconductor dosimeters with a range of radiation qualities used for mammography: A calibration laboratory study

Performance of semiconductor dosimeters with a range of radiation qualities used for mammography: A calibration laboratory study

Evaluation of a combined respiratory‐gating system comprising the TrueBeam linear accelerator and a new real‐time tumor‐tracking radiotherapy system: a preliminary study

Characteristic evaluation of a simple hand-made semiconductor dosimeter for mammography

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