Planning for mARC treatments with the Eclipse treatment planning system

Abstract

While modulated arc (mARC) capabilities have been available on Siemens linear accelerators for almost two years now, there was, until recently, only one treatment planning system capable of planning these treatments. The Eclipse treatment planning system now offers a module that can plan for mARC treatments. The purpose of this work was to test the module to determine whether it is capable of creating clinically acceptable plans. A total of 23 plans were created for various clinical sites and all plans delivered without anomaly. The average 3%/3 mm gamma pass rate for the plans was 98.0%, with a standard deviation of 1.7%. For a total of 14 plans, an equivalent static gantry IMRT plan was also created to compare delivery time. In all but two cases, the mARC plans delivered significantly faster than the static gantry plan. We have confirmed the successful creation of mARC plans that are deliverable with high fidelity on an ARTISTE linear accelerator, thus demonstrating the successful implementation of the Eclipse mARC module.PACS numbers: 87.55.D‐, 87.55.ne, 87.57.uq,

Clinical experience with planning, quality assurance, and delivery of burst‐mode modulated arc therapy

“…The total number of MU per fraction among our Monaco prostate mARC plans ranged from approximately 350 to approximately 750. Among the Monaco single-arc prostate plans, our results compare favorably with the results of Eclipse (Varian Medical Systems, Inc., Palo Alto, CA) mARC plans for 180 cGy per fraction prostate cases using the 7MV FFF beam; Sarkar et al (8) reported the total MU ranging from approximately 480 to 1,240. Our results are also consistent with those reported using the Prowess Panther (Prowess Inc., Concord, CA) treatment planning system; Dzierma et al (17) achieved Prowess-generated mARC prostate plans with MU per fraction ranging from 365 to 452 using 6MV FF photons and 366 to 507 using 7MV FFF beams.…”

“…Our results are also consistent with those reported using the Prowess Panther (Prowess Inc., Concord, CA) treatment planning system; Dzierma et al (17) achieved Prowess-generated mARC prostate plans with MU per fraction ranging from 365 to 452 using 6MV FF photons and 366 to 507 using 7MV FFF beams. One possible explanation for the difference in MU per fraction among single-arc Monaco, Prowess, and Eclipse plans is that the number of arclets per arcs among our Monaco cases may have been consistent with the Prowess plans in the Dzierma study (17) and considerably less than those for the Eclipse plans in the Sarkar study; (8) unfortunately, neither report summarized the number of arclets per arc among their final plans.…”

“…With regard to organ-at-risk (OAR) avoidance, in general all three techniques were comparable. (3) Clinical treatments using mARC have been available in the United States since 2013; (8) our institution has been using mARC clinically since January of 2014. In this report, we present our recent experience in the planning techniques, quality assurance (QA) measurements, and delivery of mARC plans that were generated using a Monte Carlo-based planning system with a two-step optimization algorithm, applying both flattened and unflat beams.…”