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.
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 cancerpatients 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.
Authors: Valerie K Reed; Wendy A Woodward; Lifei Zhang; Eric A Strom; George H Perkins; Welela Tereffe; Julia L Oh; T Kuan Yu; Isabelle Bedrosian; Gary J Whitman; Thomas A Buchholz; Lei Dong Journal: Int J Radiat Oncol Biol Phys Date: 2008-09-17 Impact factor: 7.038
Authors: Jinzhong Yang; Wendy A Woodward; Valerie K Reed; Eric A Strom; George H Perkins; Welela Tereffe; Thomas A Buchholz; Lifei Zhang; Peter Balter; Laurence E Court; X Allen Li; Lei Dong Journal: Int J Radiat Oncol Biol Phys Date: 2014-03-07 Impact factor: 7.038