Dosimetry quality control based on percent depth dose rate variation for checking beam quality in radiotherapy

Bencheikh, Mohamed; Maghnouj, Abdelmajid; Tajmouati, Jaouad

doi:10.1016/j.rpor.2020.03.016

Cited by 2 publications

(5 citation statements)

References 9 publications

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“…The measurement of LINAC output dose is part of the Quality Assurance (QA) program and the Quality Control (QC) of radiotherapy facilities [7]. Quality Assurance is a regular program or activity to ensure the consistency of medical stages [8].…”

Section: Resultsmentioning

confidence: 99%

“…The measurements were conducted in the Radiotherapy installation of Dr. SARDJITO Hospital, Yogyakarta, Indonesia. The material used in this work are: 1) Linear Accelerator LINAC Elekta Synergy Platform 154029; 2) Farmer detector PTW Freiburg with Chamber TM 30013 type for PDD measurement [7,19]; 3) electrometer; 4) water phantom; 5) slab phantom with the material specification is water equivalent white polystyrene "RW3" for high energy photon and electron energy, with dimension of 30 cm x 30 cm x 30 cm and 1.045 g/cm 3 mass-density; 6) barometer; 7) thermometer and 8) electron applicator with 10 cm x 10 cm dimension. Dosimetry measurements were conducted on the source to a surface distance (SSD) 100 cm with a field area of 10 cm x 10 cm on the phantom surface [7,11,12,19].…”

Section: Methods Dose Measurementmentioning

confidence: 99%

“…Where MQ is corrected chamber response, Dw,Q is the water absorbed dose at the Q beam quality, kQ,Q0 is the beam quality conversion factor, and ND,w,Q0 shows the chamber calibration factor at reference beam quality of Q0. Then, the radiation absorbed dose at the depth of maximum dose (Dmax) can be calculated through EQUATION (7). PDD (zref) is percentage depth dose at reference depth (zref) in field size of 10 cm x 10 cm.…”

Section: Absolute Dosimetrymentioning

confidence: 99%

“…In contrast, the stability of the beam of radiation output of the LINAC greatly influences the dose distribution received by the patient. Therefore, the LINAC requires a routine calibration to control the accuracy of the patient's received dose, which included in the quality control procedures in the quality management system [7,8]. Various dosimetry methods have been developed for calibration with various specified reference conditions both of absolute dosimetry and relative dosimetry, for instance ionomic dosimetry, gel dosimetry, film dosimetry, luminescence dosimetry, and others [9,10,11].…”

Section: Introductionmentioning

confidence: 99%

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Implementation of TRS-398 Protocol in Routine Calibration of Linac by Determination of Slab Phantom on Water Phantom Correction Factor

Fauzi

Aliyah

Darmawati

2022

SPEKTRA

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The water phantom is used for LINAC calibration to measure absorbed dose radiation. Practically, it requires a long preparation time and is considered less efficient. To increase efficiency, the medical physics team in a hospital uses slab phantom as the calibration tool. Consequently, the correction factor is crucial to define the equivalence of the absorbed doses resulted from slab phantom. The absorbed dose measurement was performed according to the IAEA TRS-398 dosimetry protocol with a cylindrical ionization chamber detector for 6 MV photon beam and electron beams from Elekta Synergy Platform 154029 LINAC with 6 MeV, 8 MeV, 10 MeV, and 12 MeV energy variations. The field size for slab and water phantom is 30 cm x 30 cm x 30 cm. Based on the TRS-398 protocol, the correction factor of the slab phantom calculated based on absolute dosimetry for 6 MV photons beam, the electron beam of 6 MeV, 8 MeV, 10 MeV, and 12 MeV are 1.0018; 0.9995; 0.9979; 1.0041 and 1.0068, respectively. As a result, the absorbed dose radiation measured by the calibrated slab phantom using the resulted correction factor has an equivalent amount to the water phantom.

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Section: Resultsmentioning

confidence: 99%

Section: Methods Dose Measurementmentioning

confidence: 99%

Section: Absolute Dosimetrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Implementation of TRS-398 Protocol in Routine Calibration of Linac by Determination of Slab Phantom on Water Phantom Correction Factor

Fauzi

Aliyah

Darmawati

2022

SPEKTRA

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“…Praveen Kumar [4] and Sadiq R. Malik et al [17]. In radiotherapy, if the uncertainties in PDDs are reduced, the accuracy in absorbed dose to tumor will be considerably improved and organ at risk (OAR) will be accurately spared [20]. For experimental data the measured PDDs for Co-60 machine should be within acceptable limit of ± 2% [17] of the published data, while for theoretical data the acceptable limit should not more than ± 20% [21].…”

Section: Methodsmentioning

confidence: 99%

Comparison of Percentage Depth Doses with the Published Data for Co-60 Radiotherapy Machine at a Regional Cancer Hospital

Ali,

Sohail,

Samad

et al. 2023

J. Phys. Appl.

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In external beam radiation therapy, the percentage depth dose (PDD) is a main factor for estimation of patient’s dose and dose distribution in target volume, therefore its accurate estimation is important. The purpose of this article is to compare PDDs with the published PDDs of different authors along central axis at different depths and field sizes for cobalt-60 (Co-60) radiotherapy machine at a regional cancer hospital Pakistan. A dedicated water phantom was used for estimation of PDDs at different depths and different field sizes, for Theratron phoenix Co-60 machine. It was observed that for 10×10 cm2 filed size of Co-60 beam mean percent variation in measured PDDs and published PDDs by different authors was -0.29% to 1.13%, which was within acceptable limit of ± 2%. However, for one author who used semi-empirical equation for PDDs calculation, the mean percent variation between measured PDDs and that of the author was -3.23%, 4.69% and 5.88% for 10×10 cm2, 25×25 cm2 and 30×30 cm2 field sizes of Co-60 beam respectively, which were within acceptable limit of ±10%. A noticeable increase in PDDs was observed with increase of the field size at given depth which shows obvious contribution of secondary scattered radiation. Also measured PDDs were well matched with that of published PDDs of most of the authors i.e. ± 2%, but the measured PDDs were moderately matched with that of PDDs for only one author for some field sizes and some depths i.e. ±10%, which need to be rectified by taking more such data.

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Dosimetry quality control based on percent depth dose rate variation for checking beam quality in radiotherapy

Cited by 2 publications

References 9 publications

Implementation of TRS-398 Protocol in Routine Calibration of Linac by Determination of Slab Phantom on Water Phantom Correction Factor

Implementation of TRS-398 Protocol in Routine Calibration of Linac by Determination of Slab Phantom on Water Phantom Correction Factor

Comparison of Percentage Depth Doses with the Published Data for Co-60 Radiotherapy Machine at a Regional Cancer Hospital

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