New image-processing technology for endoscopic ultrasound-guided fine-needle aspiration biopsy specimen evaluation in...

We evaluated the usefulness of a newly developed system with which the total amount of whitish cores in endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) samples is automatically calculated (automated multiband imaging system [AMUS]).

From 30 prospectively enrolled patients suspected of having pancreatic cancer, four EUS-FNAB specimens per patient were obtained. Following AMUS calculations, two specimens were prepared after stereomicroscopy-guided manual division into whitish and reddish sections (isolation group), and the other two were prepared without such division (no-isolation group). The relation of the AMUS results pertaining to the length of the manually measured whitish cores (stereo-microscopically visible white core [SVWC]) and the sample suitability for pathologic evaluation were analyzed.

Histological diagnostic accuracy was 90%; median SVWC length, 14 mm; and median area of whitish core calculated using the AMUS, 13 mm². The SVWC length correlated with whitish core amount (ρ = 0.83, p < 0.01) and adequacy score (ρ = 0.50, p < 0.01). The whitish core amount correlated with the adequacy score (ρ = 0.40, p < 0.01). The area under the receiver-operating characteristic curve calculated for whitish core amount with respect to the histological diagnosis was 0.84 (p < 0.01; cutoff ≥ 8 mm², sensitivity 92.5%). Subgroup analysis (isolation vs. no-isolation group) revealed no significant between-group differences in the median histological adequacy (p = 0.27) or tumor cell content ratio (p = 0.28). The median scores for degree of blood contamination were significantly lower in the isolation group than in the no-isolation group (p < 0.01).

AMUS is a simple on-site verification procedure for determining the appropriate sampling tissue quantity for high diagnostic accuracy.