Figure 1.

Couch corrections after initial setup based on image guided radiation therapy. Average 3-dimensional vector couch correction after initial setup based on image guided radiation therapy for all patients, for all fractions of 6-MV flattening-filter-free O-ring linear accelerator treatment. There were no observed differences in average couch corrections between patients treated with a supraclavicular field versus without a supraclavicular field, in prone versus supine position, or bilaterally versus unilaterally.