Preoperative evaluation of XXXX .

@entity5 @entity420 @entity3
UNASSIGNED: The preoperative evaluation of @entity420 involves endoscopic ultrasound (EUS), computed tomography (CT), and positron emission tomography (PET). With routine Barrett's oesophagus surveillance, superficial @entity5 are often identified. EUS, CT and PET have a limited role in the staging of superficial @entity5 . Standard EUS has limited accuracy, but high frequency ultrasound miniprobes are valuable for assessing @entity5 stage in superficial @entity5 . However, the best method for determining depth of invasion, and thereby stage of disease, is endoscopic mucosal resection. In contrast, in advanced @entity5 , a multi-modality approach is crucial. Accurate @entity5 staging is very important since the treatment of advanced @entity5 involves a combination of chemotherapy, radiation, and surgery. EUS is very useful for staging of the @entity5 and nodes. High frequency ultrasound miniprobes provide the ability to perform staging when the lesion is obstructing the oesophageal lumen. CT and PET provide valuable information regarding node and @entity3 staging.
