Entrance and exit dose measurements with semiconductors and thermoluminescent dosemeters: a comparison of methods and in vivo results

Loncol, T.; Greffe, J.L.; Vynckier, Stefaan; Scalliet, Pierre

doi:10.1016/s0167-8140(96)01826-9

Cited by 41 publications

(31 citation statements)

References 26 publications

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“…Diode based in-vivo dosimetry has been widely explored and reported in literature (Millwater et al 1998, Alecu et al 1999, Jornet et al 2000, Fiorino et al 2000, Jursinic 2001). Similar investigations have been reported with TLDs (Loncol et al 1996, Swinnen et al 2004 and with MOSFET dosimeters (Ramaseshan et al 2004, Scarantino et al 2005, Cherpak et al 2009. Comprehensive guidelines for the implementation of in-vivo dosimetry with diodes are published by ESTRO (2001) and AAPM (2005).…”

Section: Introductionsupporting

confidence: 60%

Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in⁶⁰Co beams

Mrčela¹,

Bokulić²,

Iżewska³

et al. 2011

Phys. Med. Biol.

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A commercial optically stimulated luminescence (OSL) dosimetry system was investigated for invivo dosimetry in radiation therapy. Dosimetric characteristics of InLight dot dosimeters and a microStar reader (Landauer Inc.) were tested in 60 Co beams. Reading uncertainty of a single dosimeter was 0.6%. The reproducibility of a set of dosimeters after a single irradiation was 1.6%, while in repeated irradiations of the same dosimeters it was found to be 3.5%. When OSL dosimeters were optically bleached between exposures, the reproducibility of repeated measurements improved to 1.0%. Dosimeters were calibrated for the entrance dose measurements and a full set of correction factors was determined. A pilot patient study that followed the phantom validation testing included more than 100 measured fields with a mean relative difference of the measured entrance dose from the expected dose of 0.8% and the standard deviation of 2.5%. In conclusion, these results demonstrate that OSL dot dosimeters represent a valid alternative to already established in-vivo dosimetry systems.

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Section: Introductionsupporting

confidence: 60%

Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in⁶⁰Co beams

Mrčela¹,

Bokulić²,

Iżewska³

et al. 2011

Phys. Med. Biol.

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“…Studies have been carried out with TLD's and diodes, giving typical mean discrepancies and standard deviations for different treatments 3,[5][6][7][8][9][10][11][12][13][14][15][16] .…”

Section: Introductionmentioning

confidence: 99%

Clinical results of entrance dose in vivo dosimetry for high energy photons in external beam radiotherapy using MOSFETs

Morton

Bhat

Williams³

et al. 2007

Australas. Phys. Eng. Sci. Med.

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Thomson and Nielsen TN-502 RD MOSFETs were used for entrance dose in vivo dosimetry for 6 and 10 MV photons. A total of 24 patients were tested, 10 breast, 8 prostate, 5 lung and 1 head and neck. For prostates three fields were checked. For all other plans all fields were checked. An action threshold of 8% was set for any one field and 5% for all fields combined. The total number of fields tested was 56, with a mean discrepancy of 1.4% and S.D. of 2.6%. Breasts had a mean discrepancy of 1.8% and S.D. of 2.8%. Prostates had a mean discrepancy of 1.3% and S.D. of 2.9%. For 3 fields combined, prostates had a mean of 1.3% and S.D. of 1.8%. These results are similar to results obtained with diodes and TLDs for the same techniques.

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“…However, the use of TLDs for exit dose measurements was introduced by Kron et al 7 and the technique of TLD extrapolation was found to be applicable. Other views have also been appeared in the literature [8][9][10][11][12][13][14][15][16] to address the exit dose using different dosimeters including TLDs. Most of the discussions refer the exit dose at a point interior to the exit surface of the exposed volume.…”

Section: Introductionmentioning

confidence: 99%

A simplified approach for exit dose in vivo measurements in radiotherapy and its clinical application

Banjade

Shrestha

Shukri

et al. 2002

Australas. Phys. Eng. Sci. Med.

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This is a study using LiF:Mg;Ti thermoluminescent dosimeter (TLD) rods in phantoms to investigate the effect of lack of backscatter on exit dose. Comparing the measured dose with anticipated dose calculated using tissue maximum ratio (TMR) or percentage depth dose (PDD) gives rise to a correction factor. This correction factor may be applied to in-vivo dosimetry results to derive true dose to a point within the patient. Measurements in a specially designed humanoid breast phantom as well as patients undergoing radiotherapy treatment were also been done. TLDs with reproducibility of within +/- 3% (1 SD) are irradiated in a series of measurements for 6 and 10 MV photon beams from a medical linear accelerator. The measured exit doses for the different phantom thickness for 6 MV beams are found to be lowered by 10.9 to 14.0% compared to the dose derived from theoretical estimation (normalized dose at dmax). The same measurements for 10 MV beams are lowered by 9.0 to 13.5%. The variations of measured exit dose for different field sizes are found to be within 2.5%. The exit doses with added backscatter material from 2 mm up to 15 cm, shows gradual increase and the saturated values agreed within 1.5% with the expected results for both beams. The measured exit doses in humanoid breast phantom as well as in the clinical trial on patients undergoing radiotherapy also agreed with the predicted results based on phantom measurements. The authors' viewpoint is that this technique provides sufficient information to design exit surface bolus to restore build down effect in cases where part of the exit surface is being considered as a target volume. It indicates that the technique could be translated for in vivo dose measurements, which may be a conspicuous step of quality assurance in clinical practice.

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Entrance and exit dose measurements with semiconductors and thermoluminescent dosemeters: a comparison of methods and in vivo results

Cited by 41 publications

References 26 publications

Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in⁶⁰Co beams

Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in⁶⁰Co beams

Clinical results of entrance dose in vivo dosimetry for high energy photons in external beam radiotherapy using MOSFETs

A simplified approach for exit dose in vivo measurements in radiotherapy and its clinical application

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Entrance and exit dose measurements with semiconductors and thermoluminescent dosemeters: a comparison of methods and in vivo results

Cited by 41 publications

References 26 publications

Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in60Co beams

Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in60Co beams

Clinical results of entrance dose in vivo dosimetry for high energy photons in external beam radiotherapy using MOSFETs

A simplified approach for exit dose in vivo measurements in radiotherapy and its clinical application

Contact Info

Product

Resources

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Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in⁶⁰Co beams

Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in⁶⁰Co beams