tailieunhanh - Báo cáo khoa học: "Image guidance using 3D-ultrasound (3D-US) for daily positioning of lumpectomy cavity for boost irradiation"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: Image guidance using 3D-ultrasound (3D-US) for daily positioning of lumpectomy cavity for boost irradiation. | Chadha et al. Radiation Oncology 2011 6 45 http content 6 1 45 RADIATION ONCOLOGY RESEARCH Open Access Image guidance using 3D-ultrasound 3D-US for daily positioning of lumpectomy cavity for boost irradiation Manjeet Chadha Amy Young Charles Geraghty Robert Masino and Louis Harrison Abstract Purpose The goal of this study was to evaluate the use of 3D ultrasound 3DUS breast IGRT for electron and photon lumpectomy site boost treatments. Materials and methods 20 patients with a prescribed photon or electron boost were enrolled in this study. 3DUS images were acquired both at time of simulation to form a coregistered CT 3DUS dataset and at the time of daily treatment delivery. Intrafractional motion between treatment and simulation 3DUS datasets were calculated to determine IGRT shifts. Photon shifts were evaluated isocentrically while electron shifts were evaluated in the beam s-eye-view. Volume differences between simulation and first boost fraction were calculated. Further to control for the effect of change in seroma cavity volume due to time lapse between the 2 sets of images interfraction IGRT shifts using the first boost fraction as reference for all subsequent treatment fractions were also calculated. Results For photon boosts IGRT shifts were cm and 50 of fractions required a shift cm. Volume change between simulation and boost was 49 31 . Shifts when using the first boost fraction as reference were cm and 24 required a shift cm. For electron boosts shifts were cm and 52 fell outside the dosimetric penumbra. Interfraction analysis relative to the first fraction noted the shifts to be cm and 36 fell outside the penumbra. Conclusion The lumpectomy cavity can shift significantly during fractionated radiation therapy. 3DUS can be used to image the cavity and correct for interfractional motion. Further studies to better define the protocol for clinical application of IGRT in breast cancer is needed. .