scholarly journals Dosimetric Evaluation of the QFix kVueTM Calypso Couch Top

2021 ◽  
Vol 20 ◽  
pp. 153303382110119
Author(s):  
Lingtong Hou ◽  
Huiqin Zhang ◽  
Xiaomei Sun ◽  
Qianqian Liu ◽  
Tingfeng Chen ◽  
...  
Keyword(s):  
Treatment Plan ◽  
Field Size ◽  
Planning System ◽  
Treatment Planning System ◽  
The Real ◽  
Depth Dose ◽  
Dosimetric Accuracy ◽  
Treatment Plans ◽  
The Difference ◽  
A Minor

Purpose: To evaluate the dosimetric accuracy of the default couch model of the QFix kVueTM Calypso couch top in the treatment planning system. Methods: With the gantry 180°, field size 20 × 20 cm, 6 MV, we measured the depth dose, off-axis dose, and dose plane of different depths in the phantom with the couch rails in and out, respectively. Isocenter doses at different angles were also obtained. The results were compared to the doses calculated using the default couch top model and the real scanned couch top model. Then we revised the default model according to the measured results. Results: With “Rails In,” the depth dose, off-axis dose, and dose plane of the default couch top model had a big difference with the dose of the real scanned couch top model and the measured result. The dose of the real scanned couch top model was much closer to the measured result, but in the region of the rail edge, the difference was still significant. With “Rails Out,” there was a minor difference between the measured result, the dose of the default couch top model and the real scanned couch top model. The difference between the measurement and the default couch top model became very small after being revised. Conclusions: It is better to avoid the beam angle passing through the couch rails in treatment plans, or you should revise the parameter of the QFix kVueTM Calypso couch top model based on the measured results, and verify the treatment plan before clinical practice.

scholarly journals Semi-supervised planning method for breast electronic tissue compensation treatments based on breast radius and separation

2020 ◽  
Vol 55 (1) ◽  
pp. 106-115
Author(s):  
Alexander R. Podgorsak ◽  
Lalith K. Kumaraswamy
Keyword(s):  
Penetration Depth ◽  
Treatment Plan ◽  
Planning System ◽  
Treatment Planning System ◽  
Breast Cancer Patients ◽  
User Input ◽  
Treatment Volume ◽  
Ct Simulation ◽  
Treatment Plans ◽  
Pre Treatment

AbstractBackgroundThe aim of the study was to develop and assess a technique for the optimization of breast electronic tissue compensation (ECOMP) treatment plans based on the breast radius and separation.Materials and methodsTen ECOMP plans for 10 breast cancer patients delivered at our institute were collected for this work. Pre-treatment CT-simulation images were anonymized and input to a framework for estimation of the breast radius and separation for each axial slice. Optimal treatment fluence was estimated based on the breast radius and separation, and a total beam fluence map for both medial and lateral fields was generated. These maps were then imported into the Eclipse Treatment Planning System and used to calculate a dose distribution. The distribution was compared to the original treatment hand-optimized by a medical dosimetrist. An additional comparison was performed by generating plans assuming a single tissue penetration depth determined by averaging the breast radius and separation over the entire treatment volume. Comparisons between treatment plans used the dose homogeneity index (HI; lower number is better).ResultsHI was non-inferior between our algorithm (HI = 12.6) and the dosimetrist plans (HI = 9.9) (p-value > 0.05), and was superior than plans obtained using a single penetration depth (HI = 17.0) (p-value < 0.05) averaged over the 10 collected plans. Our semi-supervised algorithm takes approximately 20 seconds for treatment plan generation and runs with minimal user input, which compares favorably with the dosimetrist plans that can take up to 30 minutes of attention for full optimization.ConclusionsThis work indicates the potential clinical utility of a technique for the optimization of ECOMP breast treatments.

scholarly journals The Treatment Planining of Rectum Tumors and The Use of The Wedge Filter for Ensuring The Correct Isodoses

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Idajet Selmani ◽  
Partizan Malkaj
Keyword(s):  
Planning Target Volume ◽  
Treatment Plan ◽  
Target Volume ◽  
The Body ◽  
Planning System ◽  
Treatment Planning System ◽  
Volume Of Interest ◽  
Dose Volume ◽  
Treatment Plans ◽  
Wedge Filter

One of the most important issues in the field of radiotherapy is the correct distribution of the dose around the volume of interest or planning target volume (PTV). For making this possible the exact isodose in a treatment plan has to cover the PTV, so it is used the wedge which is a part of the linear accelerator head. Wedge plays the role of a filter and usually it is called wedge filter. The wedge filter is in use almost in all treatment plans, for all the parts of the body. In this paper it is consider the use of the wedge filter for treatment of rectum tumors. The process starts with the scanning of the patient and the deliantion of the interest’s volums in the Monaco system. In the following the imagins have been sent in the treatment planning system for making the nesessary plans for treatment of the rectum. Two plans were done, one with the use of the wedge and the other without using it. The dose volume histogram helps for compering the results of the plans. The best conformity of the isodoses it was for the plan with the use of wedge through volume of interest, which is planning target volume (PTV).

scholarly journals Comparison and Evaluation of Different Treatment Plans with IFRT Field and 6 and 18 MV Energies in Hodgkin’s Lymphoma Involvement Neck and Mediastinum

2017 ◽  
Vol 8 (1Mar) ◽  
Author(s):  
M B Tavakoli ◽  
M Maleki ◽  
A Akhavan ◽  
T Hadisinia ◽  
I Abedi ◽  
...  
Keyword(s):  
Treatment Plan ◽  
Planning System ◽  
Treatment Planning System ◽  
Average Dose ◽  
Multi Leaf Collimator ◽  
Treatment Plans ◽  
The Common ◽  
Scan Data ◽  
Mediastinal Involvement ◽  
Anterior Posterior

Background: Radiotherapy with large mantle field is an effective technique in increasing the risk of secondary cancers among HL (Hodgkin Lymphoma) patients; therefore, it is essential to choose an effective treatment field including the least medical conditions in radiotherapy.Objective: The present study aimed to plan separate fields for neck and mediastinum using various energies, to compare dose distribution with MLC and to block field formation.Materials and Methods: In this study, 3D conformal treatments, Siemens Oncor accelerator equipped with multi-leaf collimator (MLC) were performed to create anterior-posterior fields. CT-scan data of 18 female patients with neck and mediastinal involvement was imported in TIGRT treatment planning system, and then treatment plans were introduced.Results and Conclusion: Using treatment plan 1, photon 6 MV in neck weighting 1 from interior, 0.5 from posterior, photon 18MV in mediastinum weighting 1 from interior and 0.5 from posterior, it was shown that regarding the common treatment plan used with photon 6 MV, mean dose delivered to breast, lung, esophagus and larynx reduced 6, 7, 41 and 10 percent, respectively and uniformity index improved by 10 percent. Using block compared to MLC in all treatment plans offered improved average dose in all organs under study. To protect breast and lung while using MLC and block in the first treatment plan seemed to be more appropriate; however, using blocks in comparison to MLC increased delivered mean dose in all organs under study. Using separate fields with Pb blocks, though, showed smaller increase.

scholarly journals Dosimetric comparison of MR-linac-based IMRT and conventional VMAT treatment plans for prostate cancer

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Vanessa Da Silva Mendes ◽  
Lukas Nierer ◽  
Minglun Li ◽  
Stefanie Corradini ◽  
Michael Reiner ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Target Coverage ◽  
Treatment Delivery ◽  
Ptv Margin ◽  
Delivery Times ◽  
Low Field ◽  
Treatment Plans

Abstract Background The aim of this study was to evaluate and compare the performance of intensity modulated radiation therapy (IMRT) plans, planned for low-field strength magnetic resonance (MR) guided linear accelerator (linac) delivery (labelled IMRT MRL plans), and clinical conventional volumetric modulated arc therapy (VMAT) plans, for the treatment of prostate cancer (PCa). Both plans used the original planning target volume (PTV) margins. Additionally, the potential dosimetric benefits of MR-guidance were estimated, by creating IMRT MRL plans using smaller PTV margins. Materials and methods 20 PCa patients previously treated with conventional VMAT were considered. For each patient, two different IMRT MRL plans using the low-field MR-linac treatment planning system were created: one with original (orig.) PTV margins and the other with reduced (red.) PTV margins. Dose indices related to target coverage, as well as dose-volume histogram (DVH) parameters for the target and organs at risk (OAR) were compared. Additionally, the estimated treatment delivery times and the number of monitor units (MU) of each plan were evaluated. Results The dose distribution in the high dose region and the target volume DVH parameters (D98%, D50%, D2% and V95%) were similar for all three types of treatment plans, with deviations below 1% in most cases. Both IMRT MRL plans (orig. and red. PTV margins) showed similar homogeneity indices (HI), however worse values for the conformity index (CI) were also found when compared to VMAT. The IMRT MRL plans showed similar OAR sparing when the orig. PTV margins were used but a significantly better sparing was feasible when red. PTV margins were applied. Higher number of MU and longer predicted treatment delivery times were seen for both IMRT MRL plans. Conclusions A comparable plan quality between VMAT and IMRT MRL plans was achieved, when applying the same PTV margin. However, online MR-guided adaptive radiotherapy allows for a reduction of PTV margins. With a red. PTV margin, better sparing of the surrounding tissues can be achieved, while maintaining adequate target coverage. Nonetheless, longer treatment delivery times, characteristic for the IMRT technique, have to be expected.

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 An Integrated Framework Based on Full Monte Carlo Simulations for Double-Scattering Proton Therapy

2019 ◽  
Vol 6 (2) ◽  
pp. 31-41
Author(s):  
Jiankui Yuan ◽  
David Mansur ◽  
Min Yao ◽  
Tithi Biswas ◽  
Yiran Zheng ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Proton Therapy ◽  
Treatment Plan ◽  
Planning System ◽  
Treatment Planning System ◽  
Patient Specific ◽  
Double Scattering ◽  
Integrated Framework ◽  
End To End ◽  
Clinical Cases

ABSTRACT Purpose: We developed an integrated framework that employs a full Monte Carlo (MC) model for treatment-plan simulations of a passive double-scattering proton system. Materials and Methods: We have previously validated a virtual machine source model for full MC proton-dose calculations by comparing the percentage of depth-dose curves, spread-out Bragg peaks, and lateral profiles against measured commissioning data. This study further expanded our previous work by developing an integrate framework that facilitates its clinical use. Specifically, we have (1) constructed patient-specific applicator and compensator numerically from the plan data and incorporated them into the beamline, (2) created the patient anatomy from the computed tomography image and established the transformation between patient and machine coordinate systems, and (3) developed a graphical user interface to ease the whole process from importing the treatment plan in the Digital Imaging and Communications in Medicine format to parallelization of the MC calculations. End-to-end tests were performed to validate the functionality, and 3 clinical cases were used to demonstrate clinical utility of the framework. Results: The end-to-end tests demonstrated that the framework functioned correctly for all tested functionality. Comparisons between the treatment planning system calculations and MC results in 3 clinical cases revealed large dose difference up to 17%, especially in the beam penumbra and near the end of beam range. The discrepancy likely originates from a variety of sources, such as the dose algorithms, modeling of the beamline, and the dose metric. The agreement for other regions was acceptable. Conclusion: An integrated framework was developed for full MC simulations of double-scattering proton therapy. It can be a valuable tool for dose verification and plan evaluation.

Khảo sát một số đặc tính bức xạ của buồng ion hóa CC13 và diode bán dẫn razor đối với các chùm photon kích thước nhỏ trên máy gia tốc tuyến tính xạ trị Clinac IX

2020 ◽  
Author(s):  
Tu Vu Ngoc
Keyword(s):  
Radiation Field ◽  
Dose Response ◽  
Dose Distribution ◽  
Ionization Chamber ◽  
Field Size ◽  
Photon Beams ◽  
Silicon Diode ◽  
Depth Dose ◽  
The Difference

Purpose: Compare percent depth dose (PDD) and off-center ratio (OCR) measured by the CC13 ionization chamber and the RAZOR silicon diode in small photon beams. Method and Materials: Some dosimetric characteristics, such as PDD, OCR, penumbra and radiation field size, were considered in this study for 2x2, 3x3, and 4x4 cm2 field sizes. We used the CC13 ionization chamber and the RAZOR silicon diode to measure dose distribution with depth along the axis and off-center of the beam. From the results obtained, the team investigated the differences in radiation parameters measured by the two types of probes above. Results: There are significant differences in the radiation parameters investigated for the CC13 ionization chamber and the RAZOR silicon diode, especially the width of penumbra. For PDD curves, the difference is less than 5% from dmax to 30 cm, however the difference becomes greater in the build-up region, which reaches to 33% at the water phatom surface. The width of penumbra measured by CC13 is always larger than that of RAZOR, the ratio of the penumbra width between two detectors is 1.8 and 1.3 for energies of 6 MV and 15 MV, respectively. Conclusion: The RAZOR silicon diode has better dose response than the CC13 ionization chamber for measuring the PDD and the OCR in small photon beams.

scholarly journals Differentiation of Using Flattening Filter Free Energy in Vmat Plans for Prostate Cancer

2018 ◽  
Vol 22 ◽  
pp. 01049 ◽  
Author(s):  
Yonca Yahşi Çelen ◽  
Atilla Evcin
Keyword(s):  
Prostate Cancer ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Dose Rates ◽  
Advantages And Disadvantages ◽  
Flattening Filter Free ◽  
Significant Difference ◽  
Treatment Plans ◽  
Flattening Filter

It is aimed to compare the values of conformity index (CI), homogeneity index (HI), monitor unit (MU) of volumetrically adjusted arthritis therapy (VMAT) plans using 10 prostate cancer patients with flattened filter (FF) and without flattening filter (FFF). In the study, treatment plans were prepared using 6 FF and 6 FFF in the Eclipse (ver.13.6) treatment planning system with Varian Trilogy Linear Accelerator. When planning was completed, CI averaged 0.87, HI averaged 0.44 and MU values were found to be 591 ± 26.8, 650 ± 33.06, respectively. When the PTV coverage, CI, HI and MU comparisons were made as a result of planning, there was no significant difference when comparing VMAT plans in FFF and FF energies. When we compare the MU values, the MU increase is seen when the straightening filter is removed. In both energy modes, good homogeneity in PTV was achieved with conventional francitation and close dose rates. No significant advantages and disadvantages of the unfiltered energy mode were observed in the assessment of plan quality in terms of CI, HI.

scholarly journals Automatic Planning for Nasopharyngeal Carcinoma Based on Progressive Optimization in RayStation Treatment Planning System

2020 ◽  
Vol 19 ◽  
pp. 153303382091571
Author(s):  
Yiwei Yang ◽  
Kainan Shao ◽  
Jie Zhang ◽  
Ming Chen ◽  
Yuanyuan Chen ◽  
...  
Keyword(s):  
At Risk ◽  
Nasopharyngeal Carcinoma ◽  
Organs At Risk ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Homogeneity Index ◽  
Automatic Planning ◽  
The Difference ◽  
Better Than

Objective: To evaluate and quantify the planning performance of automatic planning (AP) with manual planning (MP) for nasopharyngeal carcinoma in the RayStation treatment planning system (TPS). Methods: A progressive and effective design method for AP of nasopharyngeal carcinoma was realized through automated scripts in this study. A total of 30 patients with nasopharyngeal carcinoma with initial treatment was enrolled. The target coverage, conformity index (CI), homogeneity index (HI), organs at risk sparing, and the efficiency of design and execution were compared between automatic and manual volumetric modulated arc therapy (VMAT) plans. Results: The results of the 2 design methods met the clinical dose requirement. The differences in D95 between the 2 groups in PTV1 and PTV2 showed statistical significance, and the MPs are higher than APs, but the difference in absolute dose was only 0.21% and 0.16%. The results showed that the conformity index of planning target volumes (PTV1, PTV2, PTVnd and PGTVnx+rpn [PGTVnx and PGTVrpn]), homogeneity index of PGTVnx+rpn, and HI of PTVnd in APs are better than that in MPs. For organs at risk, the APs are lower than the MPs, and the difference was statistically significant ( P < .05). The manual operation time in APs was 83.21% less than that in MPs, and the computer processing time was 34.22% more. Conclusion: IronPython language designed by RayStation TPS has clinical application value in the design of automatic radiotherapy plan for nasopharyngeal carcinoma. The dose distribution of tumor target and organs at risk in the APs was similar or better than those in the MPs. The time of manual operation in the plan design showed a sharp reduction, thus significantly improving the work efficiency in clinical application.

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