Jin Hwa Choi, Hyejo Ryu, Do Hoon Oh, Lee Yoo, Minsoo Chun
{"title":"Dosimetric advantages of dual arc increments for head and neck volumetric-modulated arc therapy in the Monaco treatment planning system.","authors":"Jin Hwa Choi, Hyejo Ryu, Do Hoon Oh, Lee Yoo, Minsoo Chun","doi":"10.1002/acm2.14571","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to assess the dosimetric advantages of dual arc increments in head and neck volumetric-modulated arc therapy (VMAT) in the Monaco treatment planning system (TPS).</p><p><strong>Methods: </strong>Three VMAT plans were created for each of the 10 patients by prescribing 70 Gy in 35 fractions with arc increment combinations of 30°/30°, 15°/15°, and 30°/15° in the Monaco TPS. The dose to 0.03 cm<sup>3</sup> volume (D<sub>0.03cc</sub>), conformity number, and homogeneity and gradient indices was compared for the planning target volume (PTV), and the D<sub>0.03cc</sub> and mean dose (D<sub>mean</sub>) of the spinal cord, brain stem, parotid glands were compared. For plan complexity evaluation, the monitor unit and various related metrics were compared. Wilcoxon signed-rank tests were performed across plans for the evaluated indicators.</p><p><strong>Results: </strong>For PTV, plans with 30°/15° showed comparable D<sub>0.03cc</sub> and homogeneity and gradient indices to those of plans with 30°/30° and 15°/15° while exhibiting a better conformity number. The D<sub>0.03cc</sub> for spinal cord and brain stem for plans with 30°/15° were 26.0% and 20.8% less than those with 30°/30° and 16.8% and 19.0% less than those with 15°/15°, respectively. The D<sub>mean</sub> for the left and right parotid glands under plans with 30°/15° were 17.4% and 13.2% less than those with 30°/30° and 14.0% and 9.8% less than those with 15°/15°, respectively. The total monitor unit in plans with 30°/15° was less than that in other plans but with no significance. The plans with 30°/15° showed higher modulation complexity and plan-averaged irregularity, while no significant differences observed in both plan-averaged area and modulation compared with other plans.</p><p><strong>Conclusion: </strong>In head and neck VMAT, a dual arc increment of 30°/15° seems advisable because it can substantially reduce doses to normal tissues with comparable delivery efficiency while maintaining target dose coverage.</p>","PeriodicalId":14989,"journal":{"name":"Journal of Applied Clinical Medical Physics","volume":" ","pages":"e14571"},"PeriodicalIF":2.0000,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Clinical Medical Physics","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1002/acm2.14571","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose: This study aimed to assess the dosimetric advantages of dual arc increments in head and neck volumetric-modulated arc therapy (VMAT) in the Monaco treatment planning system (TPS).
Methods: Three VMAT plans were created for each of the 10 patients by prescribing 70 Gy in 35 fractions with arc increment combinations of 30°/30°, 15°/15°, and 30°/15° in the Monaco TPS. The dose to 0.03 cm3 volume (D0.03cc), conformity number, and homogeneity and gradient indices was compared for the planning target volume (PTV), and the D0.03cc and mean dose (Dmean) of the spinal cord, brain stem, parotid glands were compared. For plan complexity evaluation, the monitor unit and various related metrics were compared. Wilcoxon signed-rank tests were performed across plans for the evaluated indicators.
Results: For PTV, plans with 30°/15° showed comparable D0.03cc and homogeneity and gradient indices to those of plans with 30°/30° and 15°/15° while exhibiting a better conformity number. The D0.03cc for spinal cord and brain stem for plans with 30°/15° were 26.0% and 20.8% less than those with 30°/30° and 16.8% and 19.0% less than those with 15°/15°, respectively. The Dmean for the left and right parotid glands under plans with 30°/15° were 17.4% and 13.2% less than those with 30°/30° and 14.0% and 9.8% less than those with 15°/15°, respectively. The total monitor unit in plans with 30°/15° was less than that in other plans but with no significance. The plans with 30°/15° showed higher modulation complexity and plan-averaged irregularity, while no significant differences observed in both plan-averaged area and modulation compared with other plans.
Conclusion: In head and neck VMAT, a dual arc increment of 30°/15° seems advisable because it can substantially reduce doses to normal tissues with comparable delivery efficiency while maintaining target dose coverage.
期刊介绍：
Journal of Applied Clinical Medical Physics is an international Open Access publication dedicated to clinical medical physics. JACMP welcomes original contributions dealing with all aspects of medical physics from scientists working in the clinical medical physics around the world. JACMP accepts only online submission.
JACMP will publish:
-Original Contributions: Peer-reviewed, investigations that represent new and significant contributions to the field. Recommended word count: up to 7500.
-Review Articles: Reviews of major areas or sub-areas in the field of clinical medical physics. These articles may be of any length and are peer reviewed.
-Technical Notes: These should be no longer than 3000 words, including key references.
-Letters to the Editor: Comments on papers published in JACMP or on any other matters of interest to clinical medical physics. These should not be more than 1250 (including the literature) and their publication is only based on the decision of the editor, who occasionally asks experts on the merit of the contents.
-Book Reviews: The editorial office solicits Book Reviews.
-Announcements of Forthcoming Meetings: The Editor may provide notice of forthcoming meetings, course offerings, and other events relevant to clinical medical physics.
-Parallel Opposed Editorial: We welcome topics relevant to clinical practice and medical physics profession. The contents can be controversial debate or opposed aspects of an issue. One author argues for the position and the other against. Each side of the debate contains an opening statement up to 800 words, followed by a rebuttal up to 500 words. Readers interested in participating in this series should contact the moderator with a proposed title and a short description of the topic
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
