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Evaluation of LiF:Mg,Ti (TLD-100) for Intraoperative Electron Radiation Therapy Quality Assurance.

Liuzzi R, Savino F, D'Avino V, Pugliese M, Cella L - PLoS ONE (2015)

Bottom Line: In the dose range of 0-10 Gy, the calibration curve was confirmed to be linear for the conventional photon beam.In the same dose region, the quadratic model performs better than the linear model when high dose-per-pulse electron beams were used (F test; p<0.05).This study demonstrates that the TLD dose response, for doses ≤10 Gy, has a parabolic behavior in high dose-per-pulse electron beams.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biostructure and Bioimaging, National Research Council (CNR), Naples, Italy.

ABSTRACT

Background: Purpose of the present work was to investigate thermoluminescent dosimeters (TLDs) response to intraoperative electron radiation therapy (IOERT) beams. In an IOERT treatment, a large single radiation dose is delivered with a high dose-per-pulse electron beam (2-12 cGy/pulse) during surgery. To verify and to record the delivered dose, in vivo dosimetry is a mandatory procedure for quality assurance. The TLDs feature many advantages such as a small detector size and close tissue equivalence that make them attractive for IOERT as in vivo dosimeters.

Methods: LiF:Mg,Ti dosimeters (TLD-100) were irradiated with different IOERT electron beam energies (5, 7 and 9 MeV) and with a 6 MV conventional photon beam. For each energy, the TLDs were irradiated in the dose range of 0-10 Gy in step of 2 Gy. Regression analysis was performed to establish the response variation of thermoluminescent signals with dose and energy.

Results: The TLD-100 dose-response curves were obtained. In the dose range of 0-10 Gy, the calibration curve was confirmed to be linear for the conventional photon beam. In the same dose region, the quadratic model performs better than the linear model when high dose-per-pulse electron beams were used (F test; p<0.05).

Conclusions: This study demonstrates that the TLD dose response, for doses ≤10 Gy, has a parabolic behavior in high dose-per-pulse electron beams. TLD-100 can be useful detectors for IOERT patient dosimetry if a proper calibration is provided.

No MeSH data available.


Related in: MedlinePlus

Thermoluminescent Dosimeters (TLDs) dose–response curve for doses between 0 Gy e 10 Gy.a) 5 MeV electron beam, b) 7 MeV electron beam, and c) 9 MeV electron beam. The red lines represent the linear fit, the green lines represent the quadratic fit. In d) the comparison between all curves is reported.
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pone.0139287.g005: Thermoluminescent Dosimeters (TLDs) dose–response curve for doses between 0 Gy e 10 Gy.a) 5 MeV electron beam, b) 7 MeV electron beam, and c) 9 MeV electron beam. The red lines represent the linear fit, the green lines represent the quadratic fit. In d) the comparison between all curves is reported.

Mentions: The TLD dose-response at 5 MeV electrons is depicted in Fig 5B. The linear model has an R2 = 0.974 while the quadratic model has an R2 = 0.999. For the 7 MeV and 9 MeV electron beams (Fig 5C and 5D), the R2 coefficients were 0.994 and 0.996 for the linear models, and 1.0 and 0.999 for the quadratic models, respectively. For all electron beams, the result of the F test approved the quadratic model (p<0.0004, Table 2). The best-fit regression coefficients for photon and electron beams were reported in Table 2.


Evaluation of LiF:Mg,Ti (TLD-100) for Intraoperative Electron Radiation Therapy Quality Assurance.

Liuzzi R, Savino F, D'Avino V, Pugliese M, Cella L - PLoS ONE (2015)

Thermoluminescent Dosimeters (TLDs) dose–response curve for doses between 0 Gy e 10 Gy.a) 5 MeV electron beam, b) 7 MeV electron beam, and c) 9 MeV electron beam. The red lines represent the linear fit, the green lines represent the quadratic fit. In d) the comparison between all curves is reported.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591127&req=5

pone.0139287.g005: Thermoluminescent Dosimeters (TLDs) dose–response curve for doses between 0 Gy e 10 Gy.a) 5 MeV electron beam, b) 7 MeV electron beam, and c) 9 MeV electron beam. The red lines represent the linear fit, the green lines represent the quadratic fit. In d) the comparison between all curves is reported.
Mentions: The TLD dose-response at 5 MeV electrons is depicted in Fig 5B. The linear model has an R2 = 0.974 while the quadratic model has an R2 = 0.999. For the 7 MeV and 9 MeV electron beams (Fig 5C and 5D), the R2 coefficients were 0.994 and 0.996 for the linear models, and 1.0 and 0.999 for the quadratic models, respectively. For all electron beams, the result of the F test approved the quadratic model (p<0.0004, Table 2). The best-fit regression coefficients for photon and electron beams were reported in Table 2.

Bottom Line: In the dose range of 0-10 Gy, the calibration curve was confirmed to be linear for the conventional photon beam.In the same dose region, the quadratic model performs better than the linear model when high dose-per-pulse electron beams were used (F test; p<0.05).This study demonstrates that the TLD dose response, for doses ≤10 Gy, has a parabolic behavior in high dose-per-pulse electron beams.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biostructure and Bioimaging, National Research Council (CNR), Naples, Italy.

ABSTRACT

Background: Purpose of the present work was to investigate thermoluminescent dosimeters (TLDs) response to intraoperative electron radiation therapy (IOERT) beams. In an IOERT treatment, a large single radiation dose is delivered with a high dose-per-pulse electron beam (2-12 cGy/pulse) during surgery. To verify and to record the delivered dose, in vivo dosimetry is a mandatory procedure for quality assurance. The TLDs feature many advantages such as a small detector size and close tissue equivalence that make them attractive for IOERT as in vivo dosimeters.

Methods: LiF:Mg,Ti dosimeters (TLD-100) were irradiated with different IOERT electron beam energies (5, 7 and 9 MeV) and with a 6 MV conventional photon beam. For each energy, the TLDs were irradiated in the dose range of 0-10 Gy in step of 2 Gy. Regression analysis was performed to establish the response variation of thermoluminescent signals with dose and energy.

Results: The TLD-100 dose-response curves were obtained. In the dose range of 0-10 Gy, the calibration curve was confirmed to be linear for the conventional photon beam. In the same dose region, the quadratic model performs better than the linear model when high dose-per-pulse electron beams were used (F test; p<0.05).

Conclusions: This study demonstrates that the TLD dose response, for doses ≤10 Gy, has a parabolic behavior in high dose-per-pulse electron beams. TLD-100 can be useful detectors for IOERT patient dosimetry if a proper calibration is provided.

No MeSH data available.


Related in: MedlinePlus