Cytotechnologist On-site Adequacy Evaluation of Thyroid FNA
Cytotechnologist On-site Adequacy Evaluation of Thyroid FNA
Over the past 10 years, the number of thyroid FNAs at our institution underwent a median annual growth rate of 2.0% in the number of patients and 2.5% in the number of thyroid FNA procedures, from 422 FNAs (357 patients) in 2002 to 821 FNAs (647 patients) in 2011. Our analysis began in 2009 for several reasons. First, the universal implementation of TBSRTC began at this time in our institution, and the standardized accuracy reporting that accompanied this change allowed for the data consistency required for such analyses. Second, the standardized diagnostic categories allow for a simultaneous analysis of the effect of specimen adequacy on the rates of the indeterminate categories. Third, although on-site evaluation has been practiced for longer than this period, it was not universal until this time. During the study period, only 17 thyroid FNAs—comprising 0.6% of all thyroid FNAs at our institution—were excluded from the study for lack of OSEA.
Monthly counts of cytotechnologist- and cytopathologist-attended OSEA are shown in Figure 1. Overall, cytotechnologists attended 64.7% of the thyroid FNAs during the study period, with a range of 34.0% to 97.7%. The monthly FNA counts varied from 43 to 101, with most of the increased volume being met by increased allocation of cytotechnologist time to attending thyroid FNA. The dramatic shift at the end of the study period reflects a change in our clinical practice; cytotechnologists are now sent to almost all thyroid OSEA. Table 1 shows a demographic comparison of patients who had a cytotechnologist- vs cytopathologist-attended OSEA. The demographics of these 2 patient groups did not differ significantly.
(Enlarge Image)
Figure 1.
On-site evaluation of adequacy (OSEA) statistics for cytotechnologists (C) and cytopathologists (M) over the study period. The total number of fine-needle aspirates for the month is shown (T).
The on-site adequacy determinations are compared with the final adequacy determinations for both cytotechnologists ( Table 2 ) and cytopathologists ( Table 3 ), and the individual breakdowns for the 3 most active cytopathologists and 5 most active cytopathologists are shown in Figure 2. Cytopathologists and cytotechnologists had similar accuracy rates of 96% and 95%, respectively (P = .33). The on-site adequacy rate was also comparable for cytotechnologists and cytopathologists (61.6% vs 65.6%; P = .0693); our study found no correlation between the experience of the cytotechnologist and the accuracy rate (P = .11). Interestingly, the final adequacy was higher than the on-site adequacy in more cytotechnologist-attended cases (26%) than in cytopathologist-attended cases (17%), and this difference is significant (P = .000001). In addition, the percentage of cases that were ultimately signed out as adequate was also significantly higher for the cases in which a cytotechnologist was present for the OSEA (81.0% vs 77.2%; P = .038). The adequacy underestimation is possibly related to the finding that cytotechnologists had access to fewer passes than cytopathologists at the time of OSEA. The median number of passes in a cytotechnologist-attended OSEA is 3 whereas cytopathologist-attended OSEAs have a median of 5 passes (P < .000001).
(Enlarge Image)
Figure 2.
Follow-up of on-site evaluations of adequacy (OSEA) for cytotechnologists (CT) and cytopathologists (MD).
The relationships between the on-site and final adequacy determinations and TBSRTC diagnoses are shown in Figure 3. Figure 3A demonstrates that when cases are upgraded from the inadequate category, they have a higher proportion of the indeterminate categories than cases that are deemed to be adequate on site (25.2% vs 11.9%; P = .00001). This finding holds when the cases deemed less than optimal and inadequate on site are included, even though the indeterminate rate is slightly lower (19.9% vs 11.9%; P = .000002). The final indeterminate diagnosis rate was comparable regardless of whether a cytotechnologist (20.7%) or cytopathologist (17.8%) rendered the OSEA (P = .43). Regardless of the OSEA, it is clear from Figure 3B that the final adequacy is associated with indeterminate TBSRTC diagnoses. Specimens with a final less-than-optimal adequacy account for only 13.8% of all thyroid FNAs but contribute 30.0% of all the indeterminate diagnoses. The indeterminate diagnosis rate for cases with a final adequacy of less-than-optimal specimens is 29.4% compared with 11.9% for cases deemed adequate at sign out (P < .0000001).
(Enlarge Image)
Figure 3.
A, Relationship between on-site adequacy evaluation and sign-out diagnosis. B, Relationship between sign-out adequacy and diagnosis. AUS, atypia of undetermined significance; SFM, suspicious for malignancy; SFN, suspicious for follicular neoplasm; SHCN, suspicious for Hürthle cell neoplasm.
Results
Over the past 10 years, the number of thyroid FNAs at our institution underwent a median annual growth rate of 2.0% in the number of patients and 2.5% in the number of thyroid FNA procedures, from 422 FNAs (357 patients) in 2002 to 821 FNAs (647 patients) in 2011. Our analysis began in 2009 for several reasons. First, the universal implementation of TBSRTC began at this time in our institution, and the standardized accuracy reporting that accompanied this change allowed for the data consistency required for such analyses. Second, the standardized diagnostic categories allow for a simultaneous analysis of the effect of specimen adequacy on the rates of the indeterminate categories. Third, although on-site evaluation has been practiced for longer than this period, it was not universal until this time. During the study period, only 17 thyroid FNAs—comprising 0.6% of all thyroid FNAs at our institution—were excluded from the study for lack of OSEA.
Monthly counts of cytotechnologist- and cytopathologist-attended OSEA are shown in Figure 1. Overall, cytotechnologists attended 64.7% of the thyroid FNAs during the study period, with a range of 34.0% to 97.7%. The monthly FNA counts varied from 43 to 101, with most of the increased volume being met by increased allocation of cytotechnologist time to attending thyroid FNA. The dramatic shift at the end of the study period reflects a change in our clinical practice; cytotechnologists are now sent to almost all thyroid OSEA. Table 1 shows a demographic comparison of patients who had a cytotechnologist- vs cytopathologist-attended OSEA. The demographics of these 2 patient groups did not differ significantly.
(Enlarge Image)
Figure 1.
On-site evaluation of adequacy (OSEA) statistics for cytotechnologists (C) and cytopathologists (M) over the study period. The total number of fine-needle aspirates for the month is shown (T).
The on-site adequacy determinations are compared with the final adequacy determinations for both cytotechnologists ( Table 2 ) and cytopathologists ( Table 3 ), and the individual breakdowns for the 3 most active cytopathologists and 5 most active cytopathologists are shown in Figure 2. Cytopathologists and cytotechnologists had similar accuracy rates of 96% and 95%, respectively (P = .33). The on-site adequacy rate was also comparable for cytotechnologists and cytopathologists (61.6% vs 65.6%; P = .0693); our study found no correlation between the experience of the cytotechnologist and the accuracy rate (P = .11). Interestingly, the final adequacy was higher than the on-site adequacy in more cytotechnologist-attended cases (26%) than in cytopathologist-attended cases (17%), and this difference is significant (P = .000001). In addition, the percentage of cases that were ultimately signed out as adequate was also significantly higher for the cases in which a cytotechnologist was present for the OSEA (81.0% vs 77.2%; P = .038). The adequacy underestimation is possibly related to the finding that cytotechnologists had access to fewer passes than cytopathologists at the time of OSEA. The median number of passes in a cytotechnologist-attended OSEA is 3 whereas cytopathologist-attended OSEAs have a median of 5 passes (P < .000001).
(Enlarge Image)
Figure 2.
Follow-up of on-site evaluations of adequacy (OSEA) for cytotechnologists (CT) and cytopathologists (MD).
The relationships between the on-site and final adequacy determinations and TBSRTC diagnoses are shown in Figure 3. Figure 3A demonstrates that when cases are upgraded from the inadequate category, they have a higher proportion of the indeterminate categories than cases that are deemed to be adequate on site (25.2% vs 11.9%; P = .00001). This finding holds when the cases deemed less than optimal and inadequate on site are included, even though the indeterminate rate is slightly lower (19.9% vs 11.9%; P = .000002). The final indeterminate diagnosis rate was comparable regardless of whether a cytotechnologist (20.7%) or cytopathologist (17.8%) rendered the OSEA (P = .43). Regardless of the OSEA, it is clear from Figure 3B that the final adequacy is associated with indeterminate TBSRTC diagnoses. Specimens with a final less-than-optimal adequacy account for only 13.8% of all thyroid FNAs but contribute 30.0% of all the indeterminate diagnoses. The indeterminate diagnosis rate for cases with a final adequacy of less-than-optimal specimens is 29.4% compared with 11.9% for cases deemed adequate at sign out (P < .0000001).
(Enlarge Image)
Figure 3.
A, Relationship between on-site adequacy evaluation and sign-out diagnosis. B, Relationship between sign-out adequacy and diagnosis. AUS, atypia of undetermined significance; SFM, suspicious for malignancy; SFN, suspicious for follicular neoplasm; SHCN, suspicious for Hürthle cell neoplasm.
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