Surface dose measurements with GafChromic EBT film for 6 and 18MV photon beams

Bilge, Hatice; Aydın, Cevdet; Okutan, Murat; Acar, Hilal

doi:10.1016/j.ejmp.2008.05.001

Cited by 49 publications

(37 citation statements)

References 11 publications

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“…The size of detectors and, especially, the thickness of its sensitive layer must be as small as possible, due to the steep dose gradient at the media interface. Gafchromic films, 22 , 23 Metal Oxide Silicon Field Effect Transistor (MOSFET) and, partially, thermoluminescent dosimeters (TLD) detectors satisfy these criteria. Hoffmann et al (14) used Gafchromic films (EBT) in heterogeneous media (CIRS IMRT Thorax Phantom) and compared the measured doses with Acuros XB and AAA calculations.…”

Section: Introductionmentioning

confidence: 99%

Comparative evaluation of modern dosimetry techniques near low‐ and high‐density heterogeneities

Alhakeem

Alshaikh

Rosenfeld

et al. 2015

J Applied Clin Med Phys

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The purpose of this study is to compare performance of several dosimetric methods in heterogeneous phantoms irradiated by 6 and 18 MV beams. Monte Carlo (MC) calculations were used, along with two versions of Acuros XB, anisotropic analytical algorithm (AAA), EBT2 film, and MOSkin dosimeters. Percent depth doses (PDD) were calculated and measured in three heterogeneous phantoms. The first two phantoms were a 30×30×30 cm3 solid‐water slab that had an air‐gap of 20×2.5×2.35 cm3. The third phantom consisted of 30×30×5 cm3 solid water slabs, two 30×30×5 cm3 slabs of lung, and one 30×30×1 cm3 solid water slab. Acuros XB, AAA, and MC calculations were within 1% in the regions with particle equilibrium. At media interfaces and buildup regions, differences between Acuros XB and MC were in the range of +4.4% to −12.8%. MOSkin and EBT2 measurements agreed to MC calculations within ∼2.5%, except for the first centimeter of buildup where differences of 4.5% were observed. AAA did not predict the backscatter dose from the high‐density heterogeneity. For the third, multilayer lung phantom, 6 MV beam PDDs calculated by all TPS algorithms were within 2% of MC. 18 MV PDDs calculated by two versions of Acuros XB and AAA differed from MC by up to 2.8%, 3.2%, and 6.8%, respectively. MOSkin and EBT2 each differed from MC by up to 2.9% and 2.5% for the 6 MV, and by −3.1% and ∼2% for the 18 MV beams. All dosimetric techniques, except AAA, agreed within 3% in the regions with particle equilibrium. Differences between the dosimetric techniques were larger for the 18 MV than the 6 MV beam. MOSkin and EBT2 measurements were in a better agreement with MC than Acuros XB calculations at the interfaces, and they were in a better agreement to each other than to MC. The latter is due to their thinner detection layers compared to MC voxel sizes.PACS numbers: 87.55.K‐, 87.55.kd, 87.55.km, 87.53.Bn, 87.55.k

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Section: Introductionmentioning

confidence: 99%

Comparative evaluation of modern dosimetry techniques near low‐ and high‐density heterogeneities

Alhakeem

Alshaikh

Rosenfeld

et al. 2015

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…Sonuçlarımız literatürle uyumludur. [13] Bilge ve ark. [13] Gafchromic EBT film ile yaptıkları çalışmada 6MV foton enerjisi için 5x5 cm 2 , 10x10 cm 2 ve 20x20 cm 2 açık alanların yüzey dozları sırasıyla %15, %20 ve %28 olarak bulmuş-lardır.…”

Section: Discussionunclassified

“…[13] Bilge ve ark. [13] Gafchromic EBT film ile yaptıkları çalışmada 6MV foton enerjisi için 5x5 cm 2 , 10x10 cm 2 ve 20x20 cm 2 açık alanların yüzey dozları sırasıyla %15, %20 ve %28 olarak bulmuş-lardır. Çalışmamızda bulduğumuz 5x5 cm 2 , 10x10 cm 2 ve 15x15 cm 2 alanlar için yüzey dozları sıra-sıyla %15.7, %19, ve %24.1 yüzey dozları literatür ile uyumludur.…”

Section: Discussionunclassified

The effects of thermoplastic masks used for immobilization of patients on surface and build-up for megavoltage radiation

Erkan¹

2013

TJ Oncol

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OBJECTIVESTo examine the effect of thermoplastic masks used for immobilization on surface dose at Co-60 and 6MV photon energies. METHODSThree pieces of Aquaplast masks were used. One of these masks was used intact as a standard. The hole diameters of the other masks were stretched 1.25 and 2-fold. The masks were numbered as 1, 2, 3. Doses were measured with Markus parallel-plate (pp) ionization chamber, EBT2 film and MOS-FET dosimetry. RESULTSThe 1, 2 and 3 numbered masks were increased the surface dose from 24.2% to %73.3, 55.6% and %40.6, respectively, for 10x10 cm 2 at Co-60. For 6MV, the surface dose of 14.4% increased to 50.1%, 34.7% and 23.7%, respectively. Markus pp results were compatible with the EBT2 film results. MOS-FET measured higher surface doses. CONCLUSIONThe surface dose increases in the presence of mask. Mask material thickness and hole diameter significantly affects the surface dose. The diameter of the holes should be enlarged or cut the relevant region.

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“…In modern radiotherapy, recurrence is generally observed at the superficial part of the CW due to the skin-sparing effect of megavoltage radiotherapy (11,22,23). According to a study using photon energy of 6 MV, the surface dose is 15%-40% lower than the prescription dose (24). The surface doses of CW need to be known during the treatment planning process.…”

Section: Discussionmentioning

confidence: 99%

Comparison of Chest Wall and Lymphatic Radiotherapy Techniques in Patients with Left Breast Carcinoma

Gültekin¹,

Karabuğa²,

Yıldız³

et al. 2014

J Breasth Health

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Objective: The aim of this study was to find the most appropriate technique for postmastectomy chest wall (CW) and lymphatic irradiation. Materials and Methods:Partially wide tangent, 30/70 photon/electron mix, 20/80 photon/electron mix and CW and internal mammary en face electron field, were studied on computerized tomography (CT) scans of 10 left breast carcinoma patients and dosimetric calculations have been studied. Dose volume histograms (DVH) obtained from treatment planning system (TPS) were used for minimal, maximal and mean doses received by the clinical target volumes and critical structures.Results: Partially wide tangent field resulted in the most homogeneous dose distribution for the CW and a significantly lower lung and heart doses compared with all other techniques. However, right breast dose was significantly higher for partially wide tangent technique than that each of the other techniques. Approximately 0.6-7.9% differences were found between thermoluminescent dosimeter (TLD) and treatment planning system (TPS). The daily surface doses calculating using Gafchromic® external beam therapy (EBT) dosimetry films were 161.8±2.7 cGy for the naked, 241.0±1.5 cGy when 0.5 cm bolus was used and 255.3±2.7 cGy when 1 cm bolus was used. Conclusion:As a result of this study, partially wide tangent field was found to be the most appropriate technique in terms of the dose distribution, treatment planning and set-up procedure. The main disadvantage of this technique was the higher dose to the contralateral breast comparing the other techniques.

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Surface dose measurements with GafChromic EBT film for 6 and 18MV photon beams

Cited by 49 publications

References 11 publications

Comparative evaluation of modern dosimetry techniques near low‐ and high‐density heterogeneities

Comparative evaluation of modern dosimetry techniques near low‐ and high‐density heterogeneities

The effects of thermoplastic masks used for immobilization of patients on surface and build-up for megavoltage radiation

Comparison of Chest Wall and Lymphatic Radiotherapy Techniques in Patients with Left Breast Carcinoma

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