Volumetric modulated Dynamic WaveArc therapy reduces the dose to the hippocampus in patients with pituitary adenomas and craniopharyngiomas

Uto, Megumi; Mizowaki, Takashi; Ogura, Kohei; Miyabe, Yuki; Nakamura, Mitsuhiro; Mukumoto, Nobutaka; Hirashima, Hideaki; Hiraoka, Masahiro

doi:10.1016/j.prro.2017.04.004

Cited by 13 publications

(11 citation statements)

References 22 publications

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“…8 The Vero4DRT has been applied to various clinical scenarios including lung, liver, pancreas, breast, prostate, bone, and brain. [9][10][11][12][13] Monte Carlo modeling is a useful option for providing secondary dose calculation verification and has the added benefit of providing "gold standard" dose calculations in inhomogeneous materials. 14…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo simulation of 6‐MV dynamic wave VMAT deliveries by Vero4DRT linear accelerator using EGSnrc moving sources

Rostamzadeh

Ishihara

Nakamura

et al. 2020

J Applied Clin Med Phys

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The commissioning and benchmark of a Monte Carlo (MC) model of the 6-MV Brainlab-Mitsubishi Vero4DRT linear accelerator for the purpose of quality assurance of clinical dynamic wave arc (DWA) treatment plans is reported. Open-source MC applications based on EGSnrc particle transport codes are used to simulate the medical linear accelerator head components. Complex radiotherapy irradiations can be simulated in a single MC run using a shared library format combined with BEAMnrc "source20." Electron energy tuning is achieved by comparing measured vs simulated percentage depth doses (PDDs) for MLC-defined field sizes in a water phantom. Electron spot size tuning is achieved by comparing measured and simulated inplane and crossplane beam profiles. DWA treatment plans generated from RayStation (RaySearch) treatment planning system (TPS) are simulated on voxelized (2.5 mm 3) patient CT datasets. Planning target volume (PTV) and organs at risk (OAR) dose-volume histograms (DVHs) are compared to TPS-calculated doses for clinically deliverable dynamic volumetric modulated arc therapy (VMAT) trajectories. MC simulations with an electron beam energy of 5.9 MeV and spot size FWHM of 1.9 mm had the closest agreement with measurement. DWA beam deliveries simulated on patient CT datasets results in DVH agreement with TPS-calculated doses. PTV coverage agreed within 0.1% and OAR max doses (to 0.035 cc volume) agreed within 1 Gy. This MC model can be used as an independent dose calculation from the TPS and as a quality assurance tool for complex, dynamic radiotherapy treatment deliveries. Full patient CT treatment simulations are performed in a single Monte Carlo run in 23 min. Simulations are run in parallel using the Condor High-Throughput Computing software 1 on a cluster of eight servers. Each server has two physical processors (Intel Xeon CPU E5-2650 0 @2.00 GHz), with 8 cores per CPU and two threads per core for 256 calculation nodes.

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Section: Introductionmentioning

confidence: 99%

Monte Carlo simulation of 6‐MV dynamic wave VMAT deliveries by Vero4DRT linear accelerator using EGSnrc moving sources

Rostamzadeh

Ishihara

Nakamura

et al. 2020

J Applied Clin Med Phys

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“…Since then, DWA has been added to noncoplanar VMAT techniques to achieve better exibility in dose shaping while keeping dosimetrically effective delivery. DWA has been reported to have dosimetric advantages over coplanar VMAT (co-VMAT) in tumors located in the midline of the body, such as skull base tumors and prostate cancers [11,12]. A study on the application of DWA in cases of LAPC using preclinical versions of the treatment planning system (TPS) concluded that it has comparable dosimetric distributions to co-VMAT (13).…”

Section: Introductionmentioning

confidence: 99%

Dosimetric benefits of dynamic wave arc over co-planar volumetric modulated radiotherapy for locally advanced pancreatic cancer

Abdelghaffar

Kishi

Ashida

et al. 2020

Preprint

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Background: Dose reduction to the duodenum is important to decrease gastrointestinal toxicities in patients with locally advanced pancreatic cancer (LAPC) treated with definitive radiotherapy. We aimed to investigate whether dynamic wave arc (DWA), a volumetric-modulated beam delivery technique with simultaneous gantry/ring rotations passing the waved trajectories, is superior to coplanar VMAT (co-VMAT) with respect to dose distributions in LAPC. Methods: DWA and co-VMAT plans were created for 13 patients with LAPC in the pancreatic head or body. The prescribed dose was 45.6 or 48 Gy in 15 fractions. The dose volume indices (DVIs) for the gross tumor volume, planning target volume (PTV), stomach, duodenum, small bowel, large bowel, kidney, liver, and spinal cord were compared between the corresponding plans. The values of the gamma passing rate, monitor unit (MU), and beam-on time were also compared. Results: DWA significantly reduced the volumes of the duodenum receiving 39, 42, and 45 Gy by 1.1, 0.8, and 0.2 cm3, respectively. However, the mean liver dose and maximal dose of the spinal cord were increased in DWA by 1.0 and 1.1 Gy, respectively. Meanwhile, there was no significant difference in the target volumes except for dose irradiated to 2% of PTV (PTV D2%) (110.4% in DWA vs. 109.6% in co-VMAT). There were also no significant differences in the other DVIs. Further, the gamma passing rate was similar in both plans. The MU and beam-on time increased in DWA by 31 MUs and 15 seconds, respectively. Conclusion: Compared with co-VMAT, DWA generated significantly lower duodenal doses with acceptable trade-offs in LAPC.

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“…Since then, DWA has been added to noncoplanar VMAT techniques to achieve better exibility in dose shaping while keeping dosimetrically effective delivery. DWA has been reported to have dosimetric advantages over coplanar VMAT (co-VMAT) in tumors located in the midline of the body, such as skull base tumors and prostate cancers [17,18]. A study on the application of DWA in cases of LAPC using preclinical versions of the treatment planning system (TPS) concluded that it has comparable dosimetric distributions to co-VMAT [19].…”

Section: Introductionmentioning

confidence: 99%

Dosimetric comparison between dynamic wave arc and co-planar volumetric modulated radiotherapy for locally advanced pancreatic cancer

Abdelghaffar¹,

Kishi²,

Ashida³

et al. 2020

Preprint

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Background: Dose reduction to the duodenum is important to decrease gastrointestinal toxicities in patients with locally advanced pancreatic cancer (LAPC) treated with definitive chemoradiotherapy. We aimed to compare dynamic wave arc (DWA), a volumetric-modulated beam delivery technique with simultaneous gantry/ring rotations passing the waved trajectories, with coplanar VMAT (co-VMAT) with respect to dose distributions in LAPC. Methods: DWA and co-VMAT plans were created for 13 patients with LAPC in the pancreatic head or body. The prescribed dose was 45.6 or 48 Gy in 15 fractions. The dose volume indices (DVIs) for the gross tumor volume, planning target volume (PTV), stomach, duodenum, small bowel, large bowel, kidney, liver, and spinal cord were compared between the corresponding plans. The values of the gamma passing rate, monitor unit (MU), and beam-on time were also compared. Results: The volumes of the duodenum receiving 39, 42, and 45 Gy were significantly reduced to 2.8, 0.8 and 0.15 cm3 in DWA from 3.9, 1.6 and 0.34 cm3 in co-VMAT, respectively. The mean dose of the liver and D2cm3 of the planning volume for the spinal cord were significantly increased to 6.9 and 31.7 Gy in DWA from 5.9 and 30.2 Gy in co-VMAT, respectively. Meanwhile, there was no significant difference in the target volumes except for dose irradiated to 2% of PTV (110.4% in DWA vs. 109.6% in co-VMAT). There were also no significant differences in the other DVIs. Further, the gamma passing rate was 96.5% for DWA and 96.7% for co-VMAT (p = 0.65). The MU was significantly higher in DWA than in co-VMAT (620 vs. 589, p = 0.001), and there was a significant increase in the beam-on time (104 sec vs. 89 sec, p = 0.04).Conclusion: DWA was superior to co-VMAT regarding dose distributions in the duodenum in LAPC, albeit with slight increasing doses to the liver and the spinal cord and increasing MU and the beam delivery time. Further evaluation is needed to know how the dose differences would affect the clinical outcomes in chemoradiotherapy for LAPC.

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Volumetric modulated Dynamic WaveArc therapy reduces the dose to the hippocampus in patients with pituitary adenomas and craniopharyngiomas

Cited by 13 publications

References 22 publications

Monte Carlo simulation of 6‐MV dynamic wave VMAT deliveries by Vero4DRT linear accelerator using EGSnrc moving sources

Monte Carlo simulation of 6‐MV dynamic wave VMAT deliveries by Vero4DRT linear accelerator using EGSnrc moving sources

Dosimetric benefits of dynamic wave arc over co-planar volumetric modulated radiotherapy for locally advanced pancreatic cancer

Dosimetric comparison between dynamic wave arc and co-planar volumetric modulated radiotherapy for locally advanced pancreatic cancer

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