[1337] A Cost-Effectiveness Analysis of Thyroid Frozen Sections

S M Voss, H S Crist, H Mani. PSMSHMC, Hershey, PA

Background: Routine use of frozen sections (FS) during thyroid surgery continues to be controversial. Studies have advocated the use of FS only in cases labeled suspicious or indeterminate on cytology (FNAC). We performed a cost-effectiveness analysis of thyroid FS use to evaluate the above strategy.
Design: A retrospective analysis of the pathology database was performed to identify thyroid FS over a 7-year period. Results of FNAC, FS and final pathology (FHP) were collated and data analyzed. Cost effectiveness was analyzed based on medicare reimbursement rates for FNAC ($134), FS ($89), surgery (lobectomy $767, thyroidectomy $970) and FHP ($219).
Results: 152 thyroid FS were carried out in the study period. FS diagnoses correlated with FHP in 128 (84%) cases (33 malignant and 95 benign). FS had a sensitivity of 64% and specificity of 94%. 115 cases had satisfactory FNAC, with a sensitivity of 73% and specificity of 64%. Of the 33 cases diagnosed as malignant on FS, 17 had a diagnosis of malignancy on FNAC and FS did not add to the surgical strategy in these cases. FS changed the surgical strategy in 20 (13%) cases that were not malignant by FNAC. Diagnoses on FS and FHP in non-malignant FNAC categories are shown in Table 1. False negative diagnoses on FS included 11 papillary carcinomas (8 micro and 3 follicular variant) and 3 minimally invasive follicular carcinoma.

Table 1
FNAC categoryFSFHP
Benign25 benign, 6FN, 3PTC27 benign, 3 PTC, 4 uCa
FN19 benign, 23 FN, 3 PTC39 benign, 3 PTC, 2 uCa, 2FCa
Suspicious4 benign, 5 FN, 6 PTC8 benign, 7 PTC
FN-follicular neoplasm, PTC-papillary thyroid carcinoma, uCa-papillary microcarcinoma, FCa-Follicular carcinoma

Based on our data, if FS had been performed in all the 125 cases that did not have a preoperative FNAC diagnosis of malignancy, and if surgical strategy of lobectomy vs. total thyroidectomy had been based on FS diagnosis in these cases, the total cost would be $85628. On the other hand, if FS were performed only in the 15 cases with a diagnosis of suspicious/indeterminate on FNAC, there would be a saving of $9790 on FS costs. However, this strategy would have missed the 6 malignancies that were diagnosed on FS in other FNAC categories (Table 1). These 6 would have required completion lobectomy at a second sitting (cost $5916), reducing the savings to $3714. It is likely that other costs of second hospitalization and lost man-hours at work would outweigh these limited savings.
Conclusions: Intraoperative FS does not yield additional information in cases with an FNAC diagnosis of malignancy. FS is both cost-effective and impacts surgical strategies in cases with non-malignant FNAC diagnoses.
Category: Head & Neck

Tuesday, March 20, 2012 1:00 PM

Poster Session IV # 173, Tuesday Afternoon


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