Indigenously developed multipurpose acrylic head phantom for verification of IMRT using film and gel dosimetry

Natanasabapathi, Gopishankar; Subbiah, Vivekanandhan; Rath, GK; Laviraj, M.A.; Kale, Shashank Sharad; Thulkar, Sanjay; Bisht, Raj Kishor; Subramani, V.

doi:10.1120/jacmp.v14i2.4041

Cited by 8 publications

(5 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar studies of S Senthil kumar et al and others from the literature were found showing the fabrication of low cost in-house phantoms [25,30,31]]. The phenomenon of interaction of high energy radiation beam into medium is a complex phenomenon.…”

Section: Discussionsupporting

confidence: 67%

Evaluating impact of medium variation on dose calculated through planning system in a low cost in-house phantom

Saini¹,

Pandey²,

Singh³

et al. 2022

Biomed. Phys. Eng. Express

View full text Add to dashboard Cite

Purpose: In radiotherapy, accuracy in dose estimation of dose calculation methods is critical. The influence of deformity on radiation dose calculations derived by planning system is evaluated in present study. The goal of study was to create a low-cost inhomogeneous phantom for measuring absorbed dose using an Ionisation chamber and Gafchromic film, which was validated using treatment planning system (TPS) dose outcome. Methods and Materials: The central axis dose calculations were computed using Pencil Beam Convolution algorithm (PBC), Collapsed Cone Convolution (CCC) and Monte Carlo (MC) algorithm in the Monaco treatment planning system using an In-house phantom (20x20x20cm3) made up of acrylic sheet containing water and inhomogeneous material wooden powder equivalent to lung. Phantom was scanned in Computed Tomography (CT) scanner and image set was sent to the planning workstation. The depth dose evaluations were performed using ionization chamber and Gafchromic film with same beam settings and monitor units in every setup. Following that, the calculated doses obtained from TPS and measured depth doses were compared. Results: The results was reported for photon energies 6MV, 10MV, 15MV, 6FFF and 10FFF at varying field sizes of 4X4 cm2, 5x5 cm2, 10x10 cm2, and 15x15 cm2. MC maximum dose variation predicted was 2.06% in 15MV of measured chamber dose and -2.06% of measured gafchromic film dose in 6MVFFF. CCC maximum dose variation predicted was 2.68% of measured chamber dose in 6MV and 3.31% of measured gafchromic film dose in 6MV whereas PB maximum dose variation predicted was -5.94% in 15MV of measured chamber dose and -11.6% of measured gafchromic film dose in 6MVFFF. Conclusion: Low-cost in-house phantoms can be utilised to assess point and planar doses during patient-specific quality assurance in centres that don't have accessibility to phantoms due to the high cost of commercially available tools.

show abstract

Section: Discussionsupporting

confidence: 67%

Evaluating impact of medium variation on dose calculated through planning system in a low cost in-house phantom

Saini¹,

Pandey²,

Singh³

et al. 2022

Biomed. Phys. Eng. Express

View full text Add to dashboard Cite

show abstract

“…Using the film dosimeters, radiation dose distributions could be measured only in a two-dimensional surface. Researchers have been motivated by these restrictions to use various gel polymers to measure complex dose distributions in radiotherapy [20, 21, 22, 23]. …”

Section: Purposementioning

confidence: 99%

Investigation of the gold nanoparticles effects on the prostate dose distribution in brachytherapy: gel dosimetry and Monte Carlo method

Khosravi¹,

Hashemi²,

Rahmani³

et al. 2016

jcb

View full text Add to dashboard Cite

PurposeIn this work, gold nanoparticles (GNPs) were embedded in the MAGIC-f polymer gel irradiated with the 192Ir brachytherapy sources.Material and methodsAt the first plexiglas phantom was made as the human pelvis. The GNPs were synthesized with 15 nm in diameter and 0.1 mM (0.0197 mg/ml) in concentration by using a chemical reduction method. Then, the MAGIC-f gel was synthesized. The fabricated gel was poured into the tubes located at the prostate (with and without the GNPs) locations of the phantom. The phantom was irradiated with 192Ir brachytherapy sources for prostate cancer. After 24 hours, the irradiated gels was read by using Siemens 1.5 Tesla MRI scanner. Following the brachytherapy practices, the absolute doses at the reference points and isodose curves were extracted and compared by experimental measurements and Monte Carlo (MC) simulations.ResultsThe mean absorbed doses in the presence of the GNPs in prostate were 14% higher than the corresponding values without the GNPs in the brachytherapy. The gamma index analysis (between gel and MC) using 7%/7 mm was also applied to the data and a high pass rate achieved (91.7% and 86.4% for analysis with/without GNPs, respectively).ConclusionsThe real three-dimensional analysis shows the comparison of the dose-volume histograms measured for planning volumes and the expected one from the MC calculation. The results indicate that the polymer gel dosimetry method, which developed and used in this study, could be recommended as a reliable method for investigating the dose enhancement factor of GNPs in brachytherapy.

show abstract

“…Custom 3D gamma analysis code was written to run in a MATLAB (The Mathworks, MA, USA) or GNU Octave (Eaton et al 2008) environment to compare measured doses against TPS predictions following the method described by Low et al (1998). The code automatically applies interpolation to the plan dataset to prevent the appearance of artefacts in the gamma distribution (Low and Dempsey 2003).…”

Section: Gamma Analysis Methodsmentioning

confidence: 99%

Marvin: an anatomical phantom for dosimetric evaluation of complex radiotherapy of the head and neck

Aitkenhead¹,

Rowbottom²,

Mackay³

2013

Phys. Med. Biol.

View full text Add to dashboard Cite

We report on the design of Marvin, a Model Anatomy for Radiotherapy Verification and audit In the head and Neck and present results demonstrating its use in the development of the Elekta volumetric modulated arc therapy (VMAT) technique at the Christie, and in the audit of TomoTherapy and Varian RapidArc at other institutions. The geometry of Marvin was generated from CT datasets of eight male and female patients lying in the treatment position, with removable inhomogeneities modelling the sinuses and mandible. A modular system allows the phantom to be used with a range of detectors, with the locations of the modules being based on an analysis of a range of typical treatment plans (27 in total) which were mapped onto the phantom geometry. Results demonstrate the use of Gafchromic EBT2/EBT3 film for measurement of relative dose in a plane through the target and organs-at-risk, and the use of a small-volume ionization chamber for measurement of absolute dose in the target and spinal cord. Measurements made during the development of the head and neck VMAT protocol at the Christie quantified the improvement in plan delivery resulting from the installation of the Elekta Integrity upgrade (which permits an effectively continuously variable dose rate), with plans delivered before and after the upgrade having 88.5 ± 9.4% and 98.0 ± 2.2% respectively of points passing a gamma analysis (at 4%, 4 mm, global). Audits of TomoTherapy and Varian RapidArc neck techniques at other institutions showed a similar quality of plan delivery as for post-Integrity Elekta VMAT: film measurements for both techniques had >99% of points passing a gamma analysis at the clinical criteria of 4%, 4 mm, global, and >95% of points passing at tighter criteria of 3%, 3 mm, global; and absolute dose measurements in the PTV and spinal cord were within 1.5% and 3.5% of the planned doses respectively for both techniques. The results demonstrate that Marvin is an efficient and effective means of assessing the quality of delivery of complex radiotherapy in the head and neck, and is a useful tool to assist development and audit of these techniques.

show abstract

Indigenously developed multipurpose acrylic head phantom for verification of IMRT using film and gel dosimetry

Cited by 8 publications

References 27 publications

Evaluating impact of medium variation on dose calculated through planning system in a low cost in-house phantom

Evaluating impact of medium variation on dose calculated through planning system in a low cost in-house phantom

Investigation of the gold nanoparticles effects on the prostate dose distribution in brachytherapy: gel dosimetry and Monte Carlo method

Marvin: an anatomical phantom for dosimetric evaluation of complex radiotherapy of the head and neck

Contact Info

Product

Resources

About