Background: Fine-needle aspiration (FNA) with ultrasonography guidance is one of the optimal techniques for the diagnostic evaluation of thyroid nodules. A significant subset of thyroid FNAs continues to be inadequate for interpretation, which potentially leads to increased costs from repeat aspirations. Numerous studies have been published regarding the influence of rapid onsite evaluation (ROSE) by cytopathologists on thyroid FNAs, some indicating that FNA is more likely to be adequate for interpretation with ROSE, while others refute this idea. To our knowledge, no meta-analysis of the literature on this subject has been undertaken.
Methods: We searched MEDLINE and EMBASE using the following search string: (needle biopsy) AND (assessment or onsite OR onsite or immediate or rapid)/title or abstract. There were no restrictions on study design, language, anatomic site, or time period. Only studies comparing two arms (with/without ROSE) at a single site were eligible for inclusion. Potentially relevant studies were subjected to a citation search (forward search) and reference search (backward search) using SCOPUS. Statistical calculations were performed using Stata Release 12. Meta-analysis was completed using a random-effect model as implemented in the metan routine in Stata.
Results: An initial search obtained 2179 studies from MEDLINE and EMBASE, and screening yielded 71 potentially relevant studies. A focused review of this subset resulted in seven full studies and one abstract that met our inclusion criteria. Our citation search using SCOPUS yielded no new studies. Overall, the average adequacy rate was 83% without ROSE compared to 92% with ROSE. Visual inspection of the data suggested that the improvement in adequacy due to ROSE may be related to the adequacy rate without ROSE. Metaregression analysis showed that the change in the adequacy rate was strongly correlated (t=-12.7, p<0.001) with the non-ROSE adequacy rate. In addition, the non-ROSE adequacy rate explained all, but 10% of the residual between study variability in the change in the adequacy rates due to ROSE.
Conclusions: ROSE is generally associated with an improvement in adequacy, but the impact of ROSE depends heavily on the initial adequacy rate. Sites with lower initial adequacy rates can benefit the most from the implementation of ROSE.