Dosimetry characteristics of GAFCHROMIC® EBT film responding to therapeutic electron beams

Su, Fan; Liu, Yaxi; Stathakis, Sotirios; Shi, Chengyu; Esquivel, Carlos O.; Papanikolaou, Nikos

doi:10.1016/j.apradiso.2007.05.005

Cited by 62 publications

(47 citation statements)

References 6 publications

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“…Su et al (20) have found that the electron energy dependence of EBT films was within

\pm 4 %

for

6 - 20 MeV

electron beams. However, energy dependence and dose dependence of EBT films become more significant when both beam energy and dose quantity are lower 21 , 22 .…”

Section: Discussionmentioning

confidence: 97%

Experimental assessment of out‐of‐field dose components in high energy electron beams used in external beam radiotherapy

Alabdoaburas

Mège

Chavaudra

et al. 2015

J Applied Clin Med Phys

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The purpose of this work was to experimentally investigate the out‐of‐field dose in a water phantom, with several high energy electron beams used in external beam radiotherapy (RT). The study was carried out for 6, 9, 12, and 18 MeV electron beams, on three different linear accelerators, each equipped with a specific applicator. Measurements were performed in a water phantom, at different depths, for different applicator sizes, and off‐axis distances up to 70 cm from beam central axis (CAX). Thermoluminescent powder dosimeters (TLD‐700) were used. For given cases, TLD measurements were compared to EBT3 films and parallel‐plane ionization chamber measurements. Also, out‐of‐field doses at 10 cm depth, with and without applicator, were evaluated. With the Siemens applicators, a peak dose appears at about 12–15 cm out of the field edge, at 1 cm depth, for all field sizes and energies. For the Siemens Primus, with a 10×10cm2 applicator, this peak reaches 2.3%, 1%, 0.9% and 1.3% of the maximum central axis dose (Dmax) for 6, 9, 12 and 18 MeV electron beams, respectively. For the Siemens Oncor, with a 10×10cm2 applicator, this peak dose reaches 0.8%, 1%, 1.4%, and 1.6% of Dmax for 6, 9, 12, and 14 MeV, respectively, and these values increase with applicator size. For the Varian 2300C/D, the doses at 12.5 cm out of the field edge are 0.3%, 0.6%, 0.5%, and 1.1% of Dmax for 6, 9, 12, and 18 MeV, respectively, and increase with applicator size. No peak dose is evidenced for the Varian applicator for these energies. In summary, the out‐of‐field dose from electron beams increases with the beam energy and the applicator size, and decreases with the distance from the beam central axis and the depth in water. It also considerably depends on the applicator types. Our results can be of interest for the dose estimations delivered in healthy tissues outside the treatment field for the RT patient, as well as in studies exploring RT long‐term effects.PACS number(s): 87.53.Bn, 87.56.bd, 87.56.J‐

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“…Su et al (20) have found that the electron energy dependence of EBT films was within

\pm 4 %

for

6 - 20 MeV

electron beams. However, energy dependence and dose dependence of EBT films become more significant when both beam energy and dose quantity are lower 21 , 22 .…”

Section: Discussionmentioning

confidence: 97%

Experimental assessment of out‐of‐field dose components in high energy electron beams used in external beam radiotherapy

Alabdoaburas

Mège

Chavaudra

et al. 2015

J Applied Clin Med Phys

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“…Many new clinics have eliminated film processing completely from the clinical area so that dosimetric film processing is no longer an option. While radiochromic film can be used for these measurements, ( 2 – 5 ) this dosimetry system requires specialized equipment which may not be available in some clinics, in addition to a careful measurement procedure to obtain accurate measures. Consequently, other dose measurement methods need to be considered, especially for use in routine clinical measurements which need to be assessed in time periods shorter than a day.…”

Section: Introductionmentioning

confidence: 99%

Small field electron beam dosimetry using MOSFET detector

Amin

Heaton

Norrlinger

et al. 2010

J Applied Clin Med Phys

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The dosimetry of very small electron fields can be challenging due to relative shifts in percent depth‐dose curves, including the location of dmax, and lack of lateral electronic equilibrium in an ion chamber when placed in the beam. Conventionally a small parallel plate chamber or film is utilized to perform small field electron beam dosimetry. Since modern radiotherapy departments are becoming filmless in favor of electronic imaging, an alternate and readily available clinical dosimeter needs to be explored. We have studied the performance of MOSFET as a relative dosimeter in small field electron beams. The reproducibility, linearity and sensitivity of a high‐sensitivity microMOSFET were investigated for clinical electron beams. In addition, the percent depth doses, output factors and profiles have been measured in a water tank with MOSFET and compared with those measured by an ion chamber for a range of field sizes from 1 cm diameter to 10 cm× 10 cm for 6, 12, 16 and 20 MeV beams. Similar comparative measurements were also performed with MOSFET and films in solid water phantom. The MOSFET sensitivity was found to be practically constant over the range of field sizes investigated. The dose response was found to be linear and reproducible (within ±1% for 100 cGy). An excellent agreement was observed among the central axis depth dose curves measured using MOSFET, film and ion chamber. The output factors measured with MOSFET for small fields agreed to within 3% with those measured by film dosimetry. Overall results indicate that MOSFET can be utilized to perform dosimetry for small field electron beam.PACS number: 87.55.Qr

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“…The main benefits of these detectors are their high spatial resolution, low sensitivity to visible light, tissue equivalence, permanent information record and a low energy dependence (3,4,5,6).…”

Section: Introductionmentioning

confidence: 99%