Purpose: To evaluate the effect of set-up errors in breast cancer patients receiving breast irradiation using Active Breathing Coordinator system (ABC system) with deep inspiration breath hold (DIBH) or free breathing (FB). Patients and Methods: We retrospectively estimated set-up errors in ten breast cancer patients receiving breast irradiation using ABC system with DIBH (DIBH) or FB. Daily image guided radiation therapy (IGRT) would be practiced for getting images in DIBH during deep inspiratory using ABC system and FB. In comparison with initial images in soft tissue windows from computed tomography simulator (CT-simulator), we have 280 images in DIBH and FB, respectively. Results: There were 3 patients during DIBH and 7 patients during FB having significant set-up errors in the orientation of right to left (R/L). In the orientation of superior to inferior (S/I), there were 8 patients during DIBH and 2 patients during FB having significant set-up error. Ten patients during during FB having significant set-up error in the orientation of anterior to posterior (A/P). Conclusions: ABC system with DIBH could reduced the set-up errors in the orientation of A/P, but not R/L and S/I.
- Active breathing coordinator system (ABC system)
- Image guided radiation therapy (IGRT)
- Cone-beam computed tomography (CBCT)