Hybrid IMRT plans--concurrently treating conventional and IMRT beams for improved breast irradiation and reduced planning time

Int J Radiat Oncol Biol Phys. 2005 Mar 1;61(3):922-32. doi: 10.1016/j.ijrobp.2004.10.033.

Abstract

Purpose: To evaluate a hybrid intensity modulated radiation therapy (IMRT) technique as a class solution for treatment of the intact breast.

Methods and materials: The following five plan techniques were compared for 10 breast patients using dose-volume histogram analysis: conventional wedged-field tangents (Tangents), forward-planned field-within-a-field tangents (FIF), IMRT-only tangents (IMRT tangents), conventional open plus IMRT tangents (4-field hybrid), and conventional open plus IMRT tangents with 2 anterior oblique IMRT beams (6-field hybrid).

Results: The 4-field hybrid and FIF achieved dose distributions better than Tangents and IMRT tangents. The volume of tissue outside the planning target volume receiving > or =110% of prescribed dose was largest for IMRT tangents (average 158 cc) and least for 6-field hybrid (average 1 cc); the FIF and 4-field hybrid were comparable (average 15 cc). Heart volume > or =30 Gy averaged 13 cc for all techniques, except Tangents, for which it was 32 cc. Average total lung volume > or =20 Gy was 7% for all. Contralateral breast doses were < 3% for all. Planning time for hybrid techniques was significantly less than for conventional FIF technique.

Conclusions: The 4-field hybrid technique is a viable class solution. The 6-field hybrid technique creates the most conformal dose distribution at the expense of more normal tissue receiving low dose.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / diagnostic imaging
  • Breast Neoplasms / pathology
  • Breast Neoplasms / radiotherapy*
  • Female
  • Humans
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted
  • Radiotherapy, Conformal / methods*
  • Tomography, X-Ray Computed / methods