scholarly journals Volumetric modulated arc therapy for total body irradiation: A feasibility study using Pinnacle3 treatment planning system and Elekta Agility™ linac

2018 ◽  
Vol 19 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Kirsty Symons ◽  
Colm Morrison ◽  
Jason Parry ◽  
Simon Woodings ◽  
Yvonne Zissiadis
2018 ◽  
Vol 17 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Jalil ur Rehman ◽  
Muhammad Isa ◽  
Nisar Ahmad ◽  
H. M. Noor ul Huda Khan Asghar ◽  
Zaheer A. Gilani ◽  
...  

AbstractBackgroundAccurate three-dimensional dosimetry is essential in modern radiotherapy techniques such as volumetric-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). In this research work, the PRESAGE® dosimeter was used as quality assurance (QA) tool for VMAT planning for head and neck (H&N) cancer.Material and methodComputer tomography (CT) scans of an Image Radiation Oncology Core (IROC) H&N anthropomorphic phantom with both IROC standard insert and PRESAGE® insert were acquired separately. Both CT scans were imported into the Pinnacle (9.4 version) TPS for treatment planning, where the structures [planning target volume (PTV), organs at risk) and thermoluminescent detectors (TLDs) were manually contoured and used to optimise a VMAT plan. Treatment planning was done using VMAT (dual arc: 182°–178°, 178°–182°). Beam profile comparisons and gamma analysis were used to quantify agreement with film, PRESAGE® measurement and treatment planning system (TPS) calculated dose distribution.ResultsThe average ratio of TLD measured to calculated doses at the four PTV locations in the H&N phantom were between 0·95 to 0·99 for all three VMAT deliveries. Dose profiles were taken along the left–right, the anterior–posterior and superior–inferior axes, and good agreement was found between the PRESAGE® and Pinnacle profile. The mean value of gamma results for three VMAT deliveries in axial and sagittal planes were found to be 94·24 and 93·16% when compared with film and Pinnacle, respectively. The average values comparing the PRESAGE® results and dose values calculated on Pinnacle were observed to be 95·29 and 94·38% in the said planes, respectively, using a 5%/3 mm gamma criteria.ConclusionThe PRESAGE® dose measurements and calculated dose of pinnacle show reasonable agreement in both axial and sagittal planes for complex dual arc VMAT treatment plans. In general, the PRESAGE® dosimeter is found to be a feasible QA tool of VMAT plan for H&N cancer treatment.


2020 ◽  
Author(s):  
Tatsuya Kamima ◽  
Yoshihiro Ueda ◽  
Jun-ichi Fukunaga ◽  
Mikoto Tamura ◽  
Yumiko Shimizu ◽  
...  

Abstract Background: The aim of this study was to investigate the performance of the RapidPlan knowledge-based treatment planning system using models including registered pseudo-structures, and to determine how many structures are required for automatic optimization of volumetric modulated arc therapy (VMAT) for postoperative uterine cervical cancer. Methods: Pseudo-structures were retrospectively contoured for patients who had completed treatment at one of five institutions. For 22 patients, RPs were generated with a single optimization for models with two (RP_2), four (RP_4), or five (RP_5) registered structures, and the dosimetric parameters of these models were compared with a clinical plan with several optimizations. The total times for pseudo-structure creation and optimization were also measured.Results: Most dosimetric parameters showed no major differences between each RP. In particular, the rectum Dmax, V50Gy, and V40Gy with RP_2, RP_4, and RP_5 were not significantly different, and were lower than those of the clinical plan. In addition, the average proportions of plans achieving acceptable criteria for all dosimetric parameters were 98%, 99%, 98%, and 98% for the clinical plan, RP_2, RP_4, and RP_5, respectively. The average times for the creation and optimization of pseudo-structures were 105, 17, 21, and 29 minutes, for the clinical plan, RP_2, RP_4, and RP_5, respectively. Conclusions: The RapidPlan model with two registered pseudo-structures could generate clinically acceptable plans while saving time. This modeling approach using pseudo-structures could possibility be used for the VMAT planning process.


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