Dosimetric study of the AAA algorithm for the VMAT technique using an anthropomorphic phantom in the pelvic region

2015 ◽  
Vol 14 (2) ◽  
pp. 162-170
Author(s):  
Vicente Puchades ◽  
Alfredo Serna ◽  
Fernando Mata-Colodro ◽  
Davis Ramos-Amores ◽  
Emilio Casal ◽  
...  
Keyword(s):  
Planning Target Volume ◽  
Dose Calculation ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Average Dose ◽  
Anthropomorphic Phantom ◽  
Calculation Algorithm ◽  
Pelvic Region ◽  
Dose Calculation Algorithm

AbstractPurposeThe objective of this work was to investigate the accuracy of AAA dose calculation algorithm for RapidArc volumetric modulated technique (VMAT) in the presence of anatomical heterogeneities in the pelvic region.Material and methodsAn anthropomorphic phantom was used to simulate a prostate case, delineating planning target volumes (PTVs) and organs at risk. VMAT plans were optimised in eclipse (v10·0) treatment planning system (TPS). The dose distributions were calculated by the AAA dose calculation algorithm. A total of 49 thermoluminiscent dosimeters were inserted into the anthropomorphic phantom and dose measurements were compared with the predicted TPS doses.ResultsThe average dose variation was −1·5% for planning target volume corresponding to the prostate and −0·3% for planning target volume corresponding to the pelvic nodes, −0·2% for the rectum, +2·4% for the bladder, −2·0% for the femoral heads and +1·0% for the intestinal package.ConclusionAAA is a reliable dose calculation for the treatment with VMAT in the anatomy of the pelvis.

Characterising intensity-modulated radiation therapy (IMRT) software following upgrades in a commercial treatment planning system

2010 ◽  
Vol 9 (4) ◽  
pp. 209-221 ◽  
Author(s):  
Connor McGarry ◽  
Monica O’Toole ◽  
Vivian Cosgrove
Keyword(s):  
Treatment Planning ◽  
Intensity Modulated Radiation Therapy ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Calculation Algorithm ◽  
Inverse Treatment Planning ◽  
Dose Calculation Algorithm ◽  
Planning Software ◽  
One Step

AbstractWhen upgrading treatment planning software, it is important to understand and characterise any changes that may have been made to the system. This includes inverse treatment planning and dose optimisation software used for intensity-modulated radiation therapy (IMRT). A systematic and practical approach to characterising dose optimisation software following upgrades is presented based on a planning study of six IMRT prostate cases using the commercial treatment planning system Oncentra Masterplan (OMP). Upgrades included general changes in the fluence to multileaf collimator (MLC) segmentation algorithm, a change from a two-step to a one-step optimisation method and an upgrade of the dose calculation algorithm. Post upgrade changes in plan parameters such as calculation times, monitor units, segments and target doses were analysed. A 32% reduction in total calculated monitor units was observed following the general software upgrade. A smaller 12% reduction was observed when using the optional one-step optimisation method rather than a two-step process using a classic dose calculation algorithm. An increase in monitor units of approximately 12% was observed when changing to an enhanced dose calculation algorithm. The enhanced dose calculation algorithm accounted for MLC type, leakage and source size unlike the previous classic dose calculation algorithm. Differences in dose to volumes between fluence segmentation and final dose calculation varied between versions. These differences were found to be minimal for the most recent treatment planning system version. Repeatability tests revealed a more effective use of the system. The characterisation of the effects of treatment planning software upgrades allowed a better appreciation of IMRT planning and delivery attributes. Although this work is based on one commercial inverse treatment planning system, it would be easily transferable to other systems as the underlying system principles are the same.

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

Dosimetric comparison of TMR10 and convolution dose calculation algorithms in GammaPlan treatment planning system

2019 ◽  
Vol 19 (1) ◽  
pp. 93-97
Author(s):  
Ethan Kendall ◽  
Ozer Algan ◽  
Yong Chen ◽  
Salahuddin Ahmad
Keyword(s):  
Gamma Knife ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Calculation Algorithm ◽  
Dose Calculation Algorithm ◽  
Convolution Algorithm ◽  
Calculation Algorithms ◽  
Dose Calculation Algorithms ◽  
Clinically Significant

AbstractAims:In this article, our goal is to compare the TMR10 and convolution dose calculation algorithm in GammaPlan used in stereotactic radiosurgery (SRS) treatments with Gamma Knife and to assess if the algorithms produce clinically significant differences.Materials and methods:Treatment plans were analysed from ten patients who have undergone Gamma Knife SRS treatments. Patient plans were retrospectively recalculated using Lesksell GammaPlan 10 treatment software utilising the TMR10 and convolution dose calculation algorithms in order to create a paired dataset for comparison. Evaluation was based on the dose volume histogram (parameters of minimum, mean, maximum and integral doses.Results:The ratios of average integral doses calculated by the convolution dose calculation algorithm to the average integral doses calculated by the TMR10 algorithm are 0·997 for the target (p=0·028), 1·048 (p=0·48) for the skull and 1·005 (p=0·68) for the brainstem.Conclusions:Although doses calculated with the convolution algorithm resulted in slightly higher mean integral doses for the brainstem and skull critical structures when compared to that of TMR10 doses, these results were not statistically or clinically significant. Thus we continue to use the TMR10 algorithm at our clinic.

Utilising virtual bolus in superficial planning target volume dose optimisation (TomoTherapy): a phantom study

2019 ◽  
Vol 19 (1) ◽  
pp. 65-70
Author(s):  
Gim Chee Ooi ◽  
Iskandar Shahrim Bin Mustafa
Keyword(s):  
Treatment Planning ◽  
Planning Target Volume ◽  
Treatment Plan ◽  
Target Volume ◽  
The Body ◽  
Phantom Study ◽  
Planning System ◽  
Treatment Planning System ◽  
Dose Volume Histograms ◽  
Photon Fluence

AbstractAim:This is a phantom study to evaluate the dosimetry effects of using virtual bolus (VB) in TomoTherapy Treatment Planning System (TPS) optimisation for superficial planning target volume (PTV) that extends to the body surface. Without VB, the inverse-planning TPS will continuously boost the photon fluence at the surface of the superficial PTV due to lack of build-up region. VB is used during TPS optimisation only and will not be present in actual treatment delivery.Materials and methods:In this study, a dummy planning target was contoured on a cylindrical phantom which extends to the phantom surface, and VB of various combinations of thickness and density was used in treatment planning optimisation with TomoTherapy TPS. The plans were then delivered with the treatment modality TomoTherapy. Radiochromic films (Gafchromic EBT3) were calibrated and used for dose profiles measurements. TomoTherapy Planned-Adaptive software was used to analyse the delivered Dose-Volume Histograms (DVHs).Results:The use of 2 mm VB was not providing adequate build-up area and was unable to reduce the hot spots during treatment planning and actual delivery. The use of 4 mm VB was able to negate the photon fluence boosting effect by the TPS, and the actual delivery showed relatively small deviations from the treatment plan. The use of 6 mm VB caused significant dose overestimation by the TPS in the superficial regions resulting in insufficient dose coverage delivered.Findings:VB with the combination of 4 mm thickness and 1·0 g/cc density provides the most robust solution for the TomoTherapy TPS optimisation of superficial PTV.

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