Thumbnail
Access Restriction
Open

Author Jeong, C. ♦ Kwak, J. ♦ Ahn, S. ♦ Kim, J. ♦ Park, J. ♦ Yoon, S. ♦ Cho, B.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword APPLIED LIFE SCIENCES ♦ RADIOLOGY AND NUCLEAR MEDICINE ♦ BEAM MONITORS ♦ COLLIMATORS ♦ FORMATES ♦ LIVER ♦ MAMMARY GLANDS ♦ RADIATION DOSES ♦ RECTUM
Abstract Purpose: A multi-leaf collimator (MLC) based dynamic wedge (MDW), which provide similar dose profile of physical wedge (PW) along x-jaw direction while significant monitor unit (MU) reduction, was developed and investigated for clinical use. Methods: A novel technique was used to create the wedge profile using MLC. A modification was applied to the DICOM-RT format file of the plan made with the PW to replace PW with MDW. The Varian enhanced dynamic wedge profile was used to produce MLC sequence, while the MU of the wedged field was recalculated using PW factor and fluence map. The profiles for all possible MDWs to substitute PWs were verified in 6/15 MV x-ray irradiations. New plans with MDWs were compared with the original plans in 5 rectal, 5 RT breast and 5 liver cases. Results: The wedge profile of the MDW fields were well matched with those of PWs inside the fields while less scatter than PW out of the fields. For plan comparisons of the clinical cases no significant dose discrepancy was observed between MDW plan and PW’s with the dose volume histograms. The maximum and mean doses in PTVs are agreed within 1.0%. The Result of OARs of MDW plans are slightly improved in the maximum doses (3.22 ∼ 150.4 cGy) and the mean doses (17.18 ∼ 85.52 cGy) on average for all cases while the prescribed doses are 45 Gy for rectal cases, 40 or 45 Gy for liver cases and 50 Gy for breast cases. The MUs of the fields which replace PW with MDW are reduced to 68% of those of PW. Conclusion: We developed a novel dynamic wedge technique with MLC that shows clinical advantage compared to PW.
ISSN 00942405
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-06-15
Publisher Place United States
Journal Medical Physics
Volume Number 42
Issue Number 6


Open content in new tab

   Open content in new tab