scholarly journals A Feasibility Study of IMRT of Lung Cancer Using Gafchromic EBT3 Film

2018 ◽  
Author(s):  
F Falahati ◽  
A Nickfarjam ◽  
M Shabani
Keyword(s):  
Treatment Planning ◽  
Dose Distribution ◽  
Organs At Risk ◽  
Three Dimensional ◽  
Optimal Dose ◽  
Good Method ◽  
Planning System ◽  
Treatment Quality ◽  
Treatment Planning System ◽  
Background Intensity

Background: Intensity modulated radiation therapy (IMRT) is an advanced method for delivery of three dimensional therapies, which provides optimal dose distribution with giving multiple nonuniform fluency to the patient. The complex dose distribution of IMRT should be checked to ensure that the accurate dose is delivered. Today, film dosimetry is a powerful tool for radiotherapy treatment Quality Assurance (QA) and a good method to verify dose distribution in phantoms. Objective: This study aimed to evaluate the accuracy of IMRT treatment planning system, Prowess Panther® software, with Gafchromic EBT3 films in a inhomogeneity phantomMethod: The IMRT plan was generated by Prowess Panther® treatment planning system (TPS) version 5.2 on a inhomogeneity phantom, then it was irradiated by ONCOR linear accelerator (Linac) with 6 (MV) photon beam energy. The Gafchromic EBT3 film located between the phantom has measured the dose distribution.­ To compare between TPS calculated doses and film measured doses, Gamma criteria 3%/3 mm, 4%/4 mm, 5%/5 mm, 6%/6 mm and 7%/7 mm Dose Difference (DD) and Distance to Agreement (DTA), respectively were used.Results: Gammas passing rates for PTV are obtained 67.5% for 3%/3mm, 78.8% for 4%/4mm, 86.3% for 5%/5mm, 91.2% for 6%/6mm and 94.3% for 7%/7mm and for organs at risk is 72.4% for 3%/3mm, 82.8% for 4%/4mm, 89.8% for 5%/5mm, 93.3% for 6%/6mm and 95.4% for 7%/7mm (respectively DD/DTA). By increasing the range of criteria the capability increased.Conclusion: The results show that the use of EBT3 film in a inhomogeneity phantoms allows us to evaluate the dose differences between the EBT3 measured dose distribution and TPS calculated dose distribution .Hence, a result Prowess Panther® TPS can be used for IMRT technique treatment.

The Role of A Conventional Simulator in Multileaf-Plan Simulation: A Proposal

2001 ◽  
Vol 87 (2) ◽  
pp. 91-94 ◽  
Author(s):  
Carlo Capirci ◽  
Polico Cesare ◽  
Giovanni Mandoliti ◽  
Giovanni Pavanato ◽  
Marcello Gava ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Organs At Risk ◽  
Three Dimensional ◽  
Planning System ◽  
Hard Copy ◽  
Treatment Planning System ◽  
Magnification Factor ◽  
Radiographic Images ◽  
Modern Computer

Modern computer networks provide satisfying levels of data recording and verification between the treatment planning system (TPS) and the accelerators, while the main weakness of the preparation chain remains the simulation. When a conventional simulator is employed, it may adversely affect the three-dimensional treatment planning system (3DPS) process because of the difficulty to document the leaf positions on the simulator location films and on the patient's skin. With a conventional simulator, hard copies of the DRRs of each field and CT scans at isocenter level are needed. In an attempt to transfer more information displayed from a BEV perspective from the 3DPS to simulator radiographs, this study aimed to reduce the quality loss by using a 2D conventional simulator in a 3DPS process. We realized an acetate photocopy of TPS data for each field, from a BEV perspective, containing: DRR, wire frames of the PTV, organs at risk and MLC aperture. The photocopies, with an appropriate magnification factor to obtain a correct projective value (ratio 1:1) at isocenter level, are carefully placed on the radiographic images on the same hard copy which allows us to better understand possible setup errors and obliges us to correct these. The method provides reliable documentation, facilitates treatment verification, and fulfils the criteria for MLC simulation. It is accurate, simple, and very inexpensive.

Effect of treatment planning system parameters on beam modulation complexity for treatment plans with single-layer multi-leaf collimator and dual-layer stacked multi-leaf collimator

2021 ◽  
pp. 20201011
Author(s):  
Paulo Quintero ◽  
Yongqiang Cheng ◽  
David Benoit ◽  
Craig Moore ◽  
Andrew Beavis
Keyword(s):  
Treatment Planning ◽  
Organs At Risk ◽  
Single Layer ◽  
Planning System ◽  
Treatment Quality ◽  
Treatment Planning System ◽  
Complexity Metrics ◽  
Beam Modulation ◽  
Multi Leaf Collimator ◽  
Dose Sparing

Objective: High levels of beam modulation complexity (MC) and monitor units (μ) can compromise the plan deliverability of intensity-modulated radiotherapy treatments. Our study evaluates the effect of three treatment planning system (TPS) parameters on MC and μ using different multi leaf collimator (MLC) architectures. Methods: 192 volumetric-modulated arc therapy plans were calculated using one virtual prostate phantom considering three main settings: (1) three TPS-parameters (Convergence; Aperture Shape Controller, ASC; and Dose Calculation Resolution, DCR) selected from Eclipse v15.6, (2) four levels of dose-sparing priority for organs at risk (OAR), and (3) two treatment units with same nominal conformity resolution and different MLC architectures (Halcyon-v2 dual-layer MLC, DL-MLC & TrueBeam single-layer MLC, SL-MLC). We use seven complexity metrics to evaluate the MC, including two new metrics for DL-MLC, assessed by their correlation with γ passing rate (GPR) analysis. Results: DL-MLC plans demonstrated lower dose-sparing values than SL-MLC plans (p < 0.05). TPS-parameters didn’t change significantly the complexity metrics for either MLC architectures. However, for SL-MLC, significant variations of μ, target volume dose-homogeneity, and dose-spillage were associated with ASC and DCR (p < 0.05). μ were found to be correlated (highly or moderately) with all complexity metrics (p < 0.05) for both MLC plans. Additionally, our new complexity metrics presented a moderate correlation with GPR (r < 0.65). An important correlation was demonstrated between MC (plan deliverability) and dose-sparing priority level for DL-MLC. Conclusions: TPS-parameters selected do not change MC for DL-MLC architecture, but they might have a potential use to control the μ, PTV homogeneity or dose spillage for SL-MLC. Our new DL-MLC complexity metrics presented important information to be considered in future pre-treatment quality assurance programs. Finally, the prominent dependence between plan deliverability and priority applied to OAR dose sparing for DL-MLC needs to be analysed and considered as an additional predictor of GPRs in further studies. Advances in knowledge: Dose-sparing priority might influence in modulation complexity of DL-MLC.

scholarly journals Evaluation of a software system for estimating planned dose error in patients, based on planar IMRT QA measurements

2014 ◽  
Vol 48 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Mohammad Bakhtiari ◽  
Ashkan Parniani ◽  
Fritz Lerma ◽  
Shannon Reynolds ◽  
James Jordan ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Organs At Risk ◽  
Intensity Modulated Radiation Therapy ◽  
Pass Rate ◽  
Planning System ◽  
Treatment Planning System ◽  
Background Intensity ◽  
Diode Array ◽  
Software System ◽  
Different Depths

Abstract Background. Intensity modulated radiation therapy (IMRT) dosimetry verification is routinely conducted via integrated or individual field dosimetry using film or a matrix of detectors. Techniques and software systems are commercially available which use individual field dosimetry measurements as input into algorithms that estimate 3D patient dose distributions on CT scan derived target volumes and organs at risk (OARs), thus allowing direct dose-volume histogram (DVH) analysis vs. treatment planning system (TPS) DVH. The purpose of this work is to present a systematic benchmarking technique to evaluate the accuracy and consistency of such a software system. Methods. A MapCheck2 diode array and 3DVH™ software from Sun Nuclear were used for this study. Delivered planar dose was measured with the diode array as an input to 3DVH™ software that was used to estimate the 3D dose matrix. Accuracy of the output of 3DVH™ is tested by comparing measured planar doses over a range of depths to the same planes reconstructed by 3DVH™. Different fields from complex IMRT cases were selected and examined in this study. The sensitivity to depth of measurement was evaluated. Results. The Gamma Index analysis, comparing calculated 3D dose with measured 3D dose with 2% and 2mm distance-to-agreement (DTA) criteria returned a pass rate of > 90% for all patient cases calculated by the treatment planning system and it returned a pass rate of > 96% in 9 out of 10 cases calculated by 3DVH™. Extracted computed dose planes with 3DVH™ software at different depths in the flat phantom passed all gamma evaluation analyses when compared to measured planes at different depths using MapCheck2. Conclusions. Studying complex head and neck IMRT fields, it was shown that the 3D dose distribution predicted by the planned dose perturbation (PDP) algorithm is both accurate and consistent.

scholarly journals Quality Assurance of Dose Distribution of Photon Beam Planning by Anisotropic Analytical Algorithm (AAA)

2013 ◽  
Vol 4 (1) ◽  
pp. 43-49
Author(s):  
M Jahangir Alam ◽  
Syed Md Akram Hussain ◽  
Kamila Afroj ◽  
Shyam Kishore Shrivastava
Keyword(s):  
Quality Assurance ◽  
Treatment Planning ◽  
Dose Distribution ◽  
Maximum Dose ◽  
Photon Beam ◽  
Field Size ◽  
Planning System ◽  
Treatment Planning System ◽  
Anisotropic Analytical Algorithm ◽  
Analytical Algorithm

A three dimensional treatment planning system has been installed in the Oncology Center, Bangladesh. This system is based on the Anisotropic Analytical Algorithm (AAA). The aim of this study is to verify the validity of photon dose distribution which is calculated by this treatment planning system by comparing it with measured photon beam data in real water phantom. To do this verification, a quality assurance program, consisting of six tests, was performed. In this program, both the calculated output factors and dose at different conditions were compared with the measurement. As a result of that comparison, we found that the calculated output factor was in excellent agreement with the measured factors. Doses at depths beyond the depth of maximum dose calculated on-axis or off-axis in both the fields or penumbra region were found in good agreement with the measured dose under all conditions of energy, SSD and field size, for open and wedged fields. In the build up region, calculated and measured doses only agree (with a difference 2.0%) for field sizes > 5 × 5 cm2 up to 25 × 25 cm2. For smaller fields, the difference was higher than 2.0% because of the difficulty in dosimetry in that region. Dose calculation using treatment planning system based on the Anisotropic Analytical Algorithm (AAA) is accurate enough for clinical use except when calculating dose at depths above maximum dose for small field size.DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14686 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 43-49

scholarly journals Dosimetric evaluation of a three-dimensional treatment planning system

2011 ◽  
Vol 36 (1) ◽  
pp. 15 ◽  
Author(s):  
Appasamy Murugan ◽  
XavierSidonia Valas ◽  
Kuppusamy Thayalan ◽  
Velayudham Ramasubramanian
Keyword(s):  
Treatment Planning ◽  
Three Dimensional ◽  
Planning System ◽  
Treatment Planning System
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