INTRODUCTION: Endoscopic ultrasound (EUS) is known to be an accurate technology to locally stage pancreatic cancer. Recently, a linear array echoendoscope (EE) (FG 32UA, Pentax Corp., Orangeburg, NY) has become available which has the potential for ultrasound directed fine needle aspiration (FNA) cytology. There is little information at present to determine whether linear array or radial scanning ultrasound is better at staging pancreatic cancer (PCa). AIM OF STUDY: This prospective study was undertaken to assess the accuracy of the linear array echoendoscope (EE) compared to the radial scanning (EE) (UM-20, Olympus America, Inc., Melville, NY) for staging pancreatic cancer METHODS: All pts with pancreatic cancer referred for endoscopic ultrasound staging were randomized to EUS evaluation with either the linear array or radial scanning EE EUS Staging accuracy was determined by surgical pathology comparison. RESULTS: 79 pts were enrolled in this study and 33 have had surgical resection. Of these, 17 pts were randomized to linear array and 16 pts to the radial scanning EE. Local staging was based on the TNM classification system. Linear Array: The overall staging accuracy for the linear array system was 16/17 (94%) for T staging and 12/17 (71%) for N staging. RADIAL: Overall staging accuracy for the radial scanning system is 14/16 (88%) for T stage and 12/16 (75%) for N staging. VASCULAR INVASION: The radial scanning instrument correctly assessed vascular invasion in 16/16 (100%) pts.(9 true negatives, 7 true positives). The linear array instrument, correctly assessed vascular invasion in 16/17 (94%) pts. (12 true negatives, 4 true positive). There was one false negative assessment of invasion SUMMARY: Overall staging accuracy for pancreatic cancer with the radial scanning instrument was 88% for T staging and 75% for N staging and with the linear array system 94% for T staging and 71% for N staging. For the assessment of vascular invasion, the radial scanning system was 100% accurate compared to 94% for linear array. CONCLUSION: Both the linear array and radial scanning EE appear equivalent for staging pancreatic cancer and assessing vascular invasion. In view of these findings and the ultrasound directed FNA biopsy capability of the linear array system, this instrument may be the preferred choice for pts. being evaluated for pancreatic masses. This randomized trial continues to determine if preliminary trends persist.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging