Surgeon-performed ultrasound guided fine-needle aspirate biopsy with report of learning curve; a consecutive case-series study

Vinay T. Fernandes,Kevin M. Higgins,Robert J. De Santis,Danny J. Enepekides

doi:10.1186/s40463-015-0099-x

Abstract

BackgroundFine-needle aspiration biopsy has become the standard of care for the evaluation of thyroid nodules. More recently, the use of ultrasound guided fine-needle aspiration biopsy (UG-FNAB) has improved adequacy of sampling. Now there has been improved access to UG-FNAB as ultrasound technology has become more accessible. Here we review the adequacy rate and learning curve of a single surgeon starting at the adoption of UG-FNAB into surgical practice.MethodsUG-FNABs performed at Sunnybrook Health Sciences Centre from 2010 to 2015 were reviewed retrospectively. Nodule characteristics were recorded along with cytopathology and final pathology reports. Chi-square analysis, followed by the reporting of odds ratios with confidence intervals, were used to assess the statistical significance and frequencies, respectively, of nodule characteristics amongst both diagnostic and non-diagnostic samples. A multiple regression analysis was conducted to determine if any nodule characteristic were predictive of adequacy of UG-FNABs. The learning curve was assessed by calculating the eventual adequacy rates across each year, and its statistical significance was measured using Fischer’s Exact Test.ResultsIn total 423 biopsies were reviewed in 289 patients. The average nodule size was 23.05 mm. When examining if each patient eventually received a diagnostic UG-FNAB, regardless of the number attempts, adequacy was seen to increase from 70.8 % in 2010 to, 81.0 % in 2011, 90.3 % in 2012, 85.7 % in 2013, 89.7 % in 2014, and 94.3 % in 2015 (Fischer’s Exact Test, p = 0.049). Cystic (χ2 = 19.70, p <0.001) nodules were found to yield higher rates of non-diagnostic samples, and their absence are predictive of obtaining an adequate biopsy as seen in a multiple regression analysis (p < 0.001) Adequacy of repeat biopsies following an initial non-diagnostic sample was 75.0 %.ConclusionsSurgeons are capable of performing UG-FNAB with a learning curve noted to achieve standard adequacy rates. Cystic nodules are shown to yield more non-diagnostic samples in the surgeon’s office.

Highlights

Fine-needle aspiration biopsy has become the standard of care for the evaluation of thyroid nodules
Charts were collated from a list created by the Sunnybrook Health Sciences Centre (SHSC) otolaryngology office manager of patients catalogued as having undergone a thyroid biopsy with ultrasound guidance in the department
The overall eventual adequacy rate was 86.8 %, which means that 86.8 % of the patients across all years, regardless of the number of biopsies, received a diagnostic ultrasound guided fine-needle aspiration biopsy (UG-fine needle aspirate biopsy (FNAB))

Summary

Introduction

Fine-needle aspiration biopsy has become the standard of care for the evaluation of thyroid nodules. The use of FNA has decreased the percentage of surgical pathology specimens containing only benign thyroid tissue, and decreased the amount of unnecessary operations While historically these biopsies have been performed by palpation alone in the office, a shift toward biopsy under ultrasound guidance has increased the adequacy rate of biopsies to greater than 80 % [1,2,3,4,5,6,7,8,9,10]. Many patients speak of the comfort they feel having their primary clinician perform the ultrasound surveillance and biopsy rather than a technologist or outside physician with whom they have no ongoing clinical relationship For those previously biopsied benign nodules of large size, the surgeon’s ability to survey them might reduce unnecessary surgery and further decrease the rate of benign pathology in surgical reports

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Conclusion