scholarly journals Effect of dental metal artifact conversion volume on dose distribution in head‐and‐neck volumetric‐modulated arc therapy

2020 ◽  
Vol 21 (12) ◽  
pp. 253-262
Author(s):  
Kenta Kitagawa ◽  
Hitoshi Ikushima ◽  
Motoharu Sasaki ◽  
Shunsuke Furutani ◽  
Takashi Kawanaka ◽  
...  
Author(s):  
Trang Hong Thi Nguyen ◽  
Akihiro Takemura ◽  
Shinichi Ueda ◽  
Kimiya Noto ◽  
Hironori Kojima ◽  
...  

Abstract Aim: To investigate the effect of different energies on dose distribution in volumetric-modulated arc therapy (VMAT) plans for head and neck cancer. Materials and methods: Data from nine patients undergoing VMAT plans using 6 MV, 10 MV and dual-energy X-ray beams with the Pinnacle 3 V 9.10 treatment planning system (Philips Medical System, Fitchburg, WI, USA) were analysed for quality using the conformity index (CI) and homogeneity index (HI) for planning target volume (PTV), and for mean and maximum dose to the organs at risk (OARs): parotid glands, brainstem, spinal cord and optic nerves. Results: There were no clear differences in the HIs of the PTV dose among the different plans. The CIs for 10 MV and dual-energy VMAT plans were superior to that of the 6 MV VMAT plan (0·8 ± 0·3, 0·8 ± 0·3, and 0·7 ± 0·2, respectively; p = 0·001). There were no significant differences in mean/maximum dose to the OARs among the three VMAT plans. Findings: Compared with the 6 MV VMAT plan, the dual-energy VMAT plan slightly increased the coverage of the PTV with the prescribed dose but did not decrease dose to the OARs.


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.


2021 ◽  
Author(s):  
Zuzanna Krawczyk ◽  
Robert Szmurlo ◽  
Pawel Zawadzki ◽  
Estera Kot ◽  
Jacek Starzynski ◽  
...  

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