Comparison Between Hybrid Direct Aperture Optimized Intensity-Modulated Radiotherapy and Forward Planning Intensity-Modulated Radiotherapy for Whole Breast Irradiation

• Published in: International journal of radiation oncology, biology, physics Vol. 76; no. 1; pp. 91 - 99
• Main Authors: Descovich, Martina, Ph.D, Fowble, Barbara, M.D, Bevan, Alison, M.D., Ph.D, Schechter, Naomi, M.D, Park, Catherine, M.D, Xia, Ping, Ph.D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2010
• Subjects: Algorithms; APERTURES; BODY; Breast - pathology; Breast cancer; Breast Neoplasms - diagnostic imaging; Breast Neoplasms - pathology; Breast Neoplasms - radiotherapy; Direct aperture optimization; DISEASES; Dose Fractionation; Feasibility Studies; Female; GLANDS; Hematology, Oncology and Palliative Medicine; Humans; Intensity-modulated radiotherapy; MAMMARY GLANDS; MEDICINE; NEOPLASMS; NUCLEAR MEDICINE; OPENINGS; OPTIMIZATION; Organ Size; ORGANS; PLANNING; Radiation Injuries - prevention & control; Radiography; RADIOLOGY; RADIOLOGY AND NUCLEAR MEDICINE; RADIOTHERAPY; Radiotherapy Planning, Computer-Assisted - methods; Radiotherapy, Intensity-Modulated - methods; Retrospective Studies; THERAPY; Tumor Burden; Direct aperture optimization; Breast cancer; Intensity-modulated radiotherapy
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2009.01.011

Purpose To investigate the planning efficiency and dosimetric characteristics of hybrid direct aperture optimized (hDAO) intensity-modulated radiotherapy (IMRT) compared with forward planning (FP)-IMRT for whole breast irradiation with two tangential beams. Methods and Materials A total of 15 patients with left-sided breast cancer, categorized with three different breast volumes, were selected for this study. All patients were treated with FP plans to 50 Gy in 25 fractions. The hDAO plans were created by combining two open fields with eight segments in two tangential beam directions and were inversely optimized. Results The FP and hDAO plans achieved similar breast coverage and sparing of critical organs. The volume of breast receiving 105% of the prescription dose was significantly smaller in the hDAO than in the FP plans: 25% vs. 63% ( p = .008) for small, 22% vs. 57% ( p = .005) for medium, and 28% vs. 53% ( p = .005) for large breasts. Furthermore, the tumor cavity coverage was slightly better in the hDAO plans (92.4% vs. 90.9%). Conclusion Compared with FP-IMRT, hDAO-IMRT provided dosimetric advantages, significantly reducing the size of the hot spot and slightly improving the coverage of the tumor cavity. In addition, hDAO-IMRT required less planning time and was less dependent on the planner's ability.