Medical College of Wisconsin
CTSICores SearchResearch InformaticsREDCap

Direct aperture optimization-based intensity-modulated radiotherapy for whole breast irradiation. Int J Radiat Oncol Biol Phys 2007 Mar 15;67(4):1248-58

Date

02/06/2007

Pubmed ID

17275205

DOI

10.1016/j.ijrobp.2006.11.036

Scopus ID

2-s2.0-33847319702   57 Citations

Abstract

PURPOSE: To investigate the technical and dosimetric advantages and the efficacy of direct aperture optimized intensity-modulated radiation therapy (DAO-IMRT) over standard (e.g., beamlet optimized) IMRT and conventional three-dimensional conformal radiotherapy (3D-CRT) for whole breast irradiation in supine and prone positions.

METHODS AND MATERIALS: We retrospectively designed DAO-IMRT plans for 15 breast cancer patients in supine (10 patients) and prone (5 patients) positions with a goal of uniform dose coverage of the whole breast. These DAO-IMRT plans were compared with standard IMRT using beamlet optimization and conventional 3D-CRT plans using wedges. All plans used opposed tangential beam arrangements.

RESULTS: In all cases, the DAO-IMRT plans were equal to or better than those generated with 3D-CRT and standard beamlet-IMRT. For supine cases, DAO-IMRT provided higher uniformity index (UI, defined as the ratio of the dose to 95% of breast volume to the maximum dose) than either 3D-CRT (0.88 vs. 0.82; p = 0.026) or beamlet-IMRT (0.89 vs. 0.85; p = 0.003). Direct aperture optimized IMRT also gave lower lung doses than either 3D-CRT (V20 = 7.9% vs. 8.6%; p = 0.024) or beamlet-IMRT (V20 = 8.4% vs. 9.7%; p = 0.0008) for supine patients. For prone patients, DAO-IMRT provided higher UI than either 3D-CRT (0.89 vs. 0.83; p = 0.027) or beamlet-IMRT (0.89 vs. 0.85; p = 0.003). The planning time for DAO-IMRT was approximately 75% less than that of 3D-CRT. The monitor units for DAO-IMRT were approximately 60% less than those of beamlet-IMRT.

CONCLUSION: Direct aperture optimized IMRT improved the overall quality of dose distributions as well as the planning and delivery efficiency for treating whole breast in both supine and prone positions.

Author List

Ahunbay EE, Chen GP, Thatcher S, Jursinic PA, White J, Albano K, Li XA

Authors

Ergun Ahunbay PhD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin
Katherine Albano Medical Physicist Sr in the Radiation Oncology department at Medical College of Wisconsin
Guang-Pei Chen PhD Assistant Professor in the Radiation Oncology department at Medical College of Wisconsin
X Allen Li PhD Professor in the Radiation Oncology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Breast Neoplasms
Female
Humans
Prone Position
Radiotherapy Dosage
Radiotherapy, Conformal
Radiotherapy, Intensity-Modulated
Retrospective Studies
Supine Position