scholarly journals Performance of a Commercial Macro Monte Carlo Dose Calculation Algorithm for Determining Output Factors of Clinical Electron Fields

2009 ◽  
Vol 8 (4) ◽  
pp. 307-314 ◽  
Author(s):  
Richard A. Popple ◽  
Ivan A. Brezovich ◽  
Prem N. Pareek ◽  
Jun Duan ◽  
Sui Shen ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Strong Dependence ◽  
Dose Calculation ◽  
Monte Carlo Algorithm ◽  
Planning System ◽  
Treatment Planning System ◽  
Large Field ◽  
Calculation Algorithm ◽  
Output Factors ◽  
The Difference

We compare measured output factors of clinical electron fields to those calculated by a commercial treatment planning system based on an electron Monte Carlo algorithm. The measured data is comprised of 195 fields with energies 6 to 18 MeV, applicator sizes 6 × 6 cm2 to 25 × 25 cm2, and source to surface distances (SSDs) of 97 to 107 cm. Due to a scarcity of clinical fields for the highest energies and the largest applicator sizes, additional measurements were made at arbitrarily chosen large field sizes at previously not used energies, for a total of 223 output factors. The difference between calculation and measurement ranged from −2.9% to 3.9%, with a mean difference of −0.2%. Half of the field shapes had a difference with magnitude less than 0.8%. Only 7 (3%) of the field shapes were outliers, having differences greater than 2%. All outliers had field widths at the normalization point < 3.5 cm, were applied at SSDs > 100 cm, were inserts for the 25 × 25 cm2 applicator, or had more than one of these characteristics. For narrow and elongated fields the TPS slightly overestimated output factors, whereas for field shapes with aspect ratio close to 1 the TPS slightly underestimated the output factors. No strong dependence of the difference on energy was observed.

Commissioning and Validation of the First Monte Carlo Based Dose Calculation Algorithm Commercial Treatment Planning System in Mexico

2010 ◽  
Author(s):  
J. M. Lárraga-Gutiérrez ◽  
O. A. García-Garduño ◽  
O. O. Galván de la Cruz ◽  
M. Hernández-Bojórquez ◽  
P. Ballesteros-Zebadúa ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Treatment Planning ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Calculation Algorithm ◽  
Dose Calculation Algorithm

Experimental validatıon of peripheral dose distribution of electron beams for eclipse electron Monte Carlo algorithm

2018 ◽  
Vol 17 (3) ◽  
pp. 279-288
Author(s):  
Hilal Acar ◽  
Mustafa Caglar ◽  
Ayse Y. Altinok
Keyword(s):  
Monte Carlo ◽  
Dose Distribution ◽  
Electron Beams ◽  
Calculated Data ◽  
Monte Carlo Algorithm ◽  
Planning System ◽  
Treatment Planning System ◽  
Large Field ◽  
Peripheral Dose ◽  
Ionisation Chamber

AbstractAimThe accuracy of two calculation algorithms of the Varian Eclipse treatment planning system (TPS), the electron Monte Carlo algorithm (eMC) and general Gaussian pencil beam algorithm (GGPB) for calculating peripheral dose distribution of electron beams was investigated.MethodsPeripheral dose measurements were carried out for 6, 9, 12, 15, 18 and 22 MeV electron beams using parallel plate ionisation chamber and EBT3 film in the slab phantom. Measurements were performed for 6×6, 10×10 and 25×25 cm2 cone sizes at dmax of each energy up to 20 cm beyond the field edges. The measured and TPS calculated data were compared.ResultsThe TPS underestimated the out-of-field doses. The difference between measured and calculated doses increase with the cone size. For ionisation chamber measurement, the largest deviation between calculated and measured doses is <4·29% using the eMC, but can increase up to 8·72% of the distribution using GGPB. For film measurement, the minimum gamma analysis passing rates between measured and calculated dose distributions for all field sizes and energies used in this study were 91·2 and 74·7% for eMC and GGPB, respectively.FindingsThe use of GGPB for planning large field treatments with 6 MeV could lead to inaccuracies of clinical significance.

scholarly journals Evaluation of a treatment planning system developed for clinical boron neutron capture therapy and validation against an independent Monte Carlo dose calculation system

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Naonori Hu ◽  
Hiroki Tanaka ◽  
Ryo Kakino ◽  
Syuushi Yoshikawa ◽  
Mamoru Miyao ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Treatment Planning ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Neutron Capture Therapy ◽  
Boron Neutron Capture ◽  
Monte Carlo Dose Calculation

AbstractBoron neutron capture therapy (BNCT) for the treatment of unresectable, locally advanced, and recurrent carcinoma of the head and neck cancer has been approved by the Japanese government for reimbursement under the national health insurance as of June 2020. A new treatment planning system for clinical BNCT has been developed by Sumitomo Heavy Industries, Ltd. (Sumitomo), NeuCure® Dose Engine. To safely implement this system for clinical use, the simulated neutron flux and gamma ray dose rate inside a water phantom was compared against experimental measurements. Furthermore, to validate and verify the new planning system, the dose distribution inside an anthropomorphic head phantom was compared against a BNCT treatment planning system SERA and an in-house developed Monte Carlo dose calculation program. The simulated results closely matched the experimental results, within 5% for the thermal neutron flux and 10% for the gamma ray dose rate. The dose distribution inside the head phantom closely matched with SERA and the in-house developed dose calculation program, within 3% for the tumour and a difference of 0.3 Gyw for the brain.

scholarly journals Benchmarking techniques for stereotactic body radiotherapy for early-stage glottic laryngeal cancer: LINAC-based non-coplanar VMAT vs. Cyberknife planning

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
You Zhang ◽  
Tsuicheng Chiu ◽  
Jeffrey Dubas ◽  
Zhen Tian ◽  
Pam Lee ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Laryngeal Cancer ◽  
Statistical Significance ◽  
Dose Calculation ◽  
Monte Carlo Algorithm ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Plan Quality ◽  
Significant Difference

Abstract Introduction Stereotactic body radiation therapy (SBRT) was found effective in treating laryngeal cancer with only five treatment fractions by a recent clinical trial (NCT01984502, ClinicalTrials.gov). Nevertheless, this trial used the Cyberknife system, which is not widely accessible enough to benefit all patients affected by laryngeal cancer. Our study investigates the feasibility of larynx SBRT treatment planning on a conventional gantry-based LINAC and compares its plan quality with that from the Cyberknife. Materials & methods Ten larynx SBRT cases were originally treated by Cyberknife using fixed cones in our institution, with plans created and optimized using the Monte-Carlo algorithm in the MultiPlan treatment planning system. These cases were retrospectively planned in the Eclipse planning system for a LINAC with the same prescription dose. We used volumetric modulated arc therapy (VMAT) for larynx SBRT planning in Eclipse and incorporated non-coplanar arcs to approach the Cyberknife’s large solid angle delivery space. We used both anisotropic analytical algorithm (AAA) and Acuros XB (AXB) algorithm for dose calculation and compared their accuracy by measurements on an in-house larynx phantom. We compared the LINAC VMAT plans (VMAT-AAA and VMAT-AXB) with the original Cyberknife plans using dosimetric endpoints such as the conformity index, gradient indices (R50, R20), OAR maximum/mean doses, and the monitor units. Results Phantom measurement showed that both the AAA and the AXB algorithms provided adequate dose calculation accuracy (94.7% gamma pass rate on 2%/2 mm criteria for AAA vs. 97.3% for AXB), though AXB provided better accuracy in the air cavity. The LINAC-based VMAT plans achieved similar dosimetric endpoints as the Cyberknife planning, and all plans met the larynx SBRT dosimetric constraints. Cyberknife plans achieved an average conformity index of 1.13, compared to 1.20 of VMAT-AXB and 1.19 of VMAT-AAA. The VMAT plans spared the thyroid gland better with average Dmean of 2.4 Gy (VMAT-AXB) and 2.7 Gy (VMAT-AAA), as compared to 4.3 Gy for Cyberknife plans. The VMAT-AAA plans had a slightly lower contralateral arytenoid Dmax (average: 15.2 Gy) than Cyberknife plans (average: 17.9 Gy) with statistical significance, while the contralateral arytenoid Dmax was similar between VMAT-AXB and Cyberknife plans with no statistically significant difference. Cyberknife plans offered slightly better R50 (average: 5.0) than VMAT-AXB (5.9) and VMAT-AAA (5.7) plans. The VMAT plans substantially reduced the plan MUs to less than 1/3 of the Cyberknife plans, and the differences were statistically significant. The other metrics were similar between VMAT and Cyberknife plans with no statistically significant differences. Conclusions Gantry-based LINACs can achieve similar plan quality to Cyberknife systems. Treatment outcome with both methods remains to be investigated.

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