Dosimetric comparison of left-sided whole breast irradiation with 3DCRT, forward-planned IMRT, inverse-planned IMRT, helical tomotherapy, and topotherapy

作者：Schubert Leah K^*; Gondi Vinai; Sengbusch Evan; Westerly David C; Soisson Emilie T; Paliwal Bhudatt R; Mackie Thomas Rockwell; Mehta Minesh P; Patel Rakesh R; Tome Wolfgang A; Cannon George M

来源：Radiotherapy and Oncology, 2011, 100(2): 241-246.

DOI：10.1016/j.radonc.2011.01.004

• Breast cancer
• Tomotherapy
• Topotherapy
• Tangents
• IMRT

Background and purpose: To compare left-sided whole breast conventional and intensity-modulated radiotherapy (IMRT) treatment planning techniques.
Materials and methods: Treatment plans were created for 10 consecutive patients. Three-dimensional conformal radiotherapy (3DCRT), forward-planned IMRT (for-IMRT), and inverse-planned IMRT (inv-IMRT) used two tangent beams. For-IMRT utilized up to four segments per beam. For helical tomotherapy (HT) plans, beamlet entrance and/or exit to critical structures was blocked. Topotherapy plans, which used static gantry angles with simultaneous couch translation and inverse-planned intensity modulation, used two tangent beams. Plans were normalized to 50 Gy to 95% of the retracted PTV.
Results: Target max doses were reduced with for-IMRT compared to 3DCRT, which were further reduced with HT, topotherapy, and inv-IMRT. FIT resulted in lowest heart and ipsilateral lung max doses, but had higher mean doses. Inv-IMRT and topotherapy reduced ipsilateral lung mean and max doses compared to 3DCRT and for-IMRT.
Conclusions: All modalities evaluated provide adequate coverage of the intact breast. HT, topotherapy, and inv-IMRT can reduce high doses to the target and normal tissues, although HT results in increased low doses to large volume of normal tissue. For-IMRT improves target homogeneity compared with 3DCRT, but to a lesser degree than the inverse-planned modalities.

• 出版日期2011-8