Figure 5.

This set of figures documents the effect of hollow organ filling on pancreatic tumor displacement recognized by ultrasound-based image guidance. The left figure shows an extended stomach at the time of original treatment CT simulation. Following consistent 3D corrective shifts >25 mm derived from ultrasound-based image guidance, the patient was re-simulated to assess the cause of shift magnitude. CT-CT comparison confirmed that the significant altered state of stomach filling had changed the target location by a calculated 3D magnitude vector of 25.1 mm (anteroposterior displacement of the displayed surgical clip 17.6 mm, left/right 6.3 mm, craniocaudally 16.7 mm). Treatment was re-planned based on the second CT scan and subsequent image guidance suggested shifts were within the range of the entire cohort.