Value of Preoperative Ultrasonography in the Surgical Management of Initial and Reoperative Papillary Thyroid Cancer

Abstract

BACKGROUND: Cervical recurrences, predominantly in lymph nodes, occur in 14% to 30% of patients with papillary thyroid cancer (PTC). Postoperative surveillance for recurrent PTC increasingly includes thyrotropin-stimulated thyroglobulin and high-resolution ultrasonography (US). This combination commonly can detect recurrent disease as small as 5 mm. HYPOTHESIS: Preoperative US will increase detection and assessment of the extent of lymph node metastasis (LNM) in patients with PTC. DESIGN: Retrospective cohort study. SETTING: Tertiary care academic center. PATIENTS: From January 1, 1999, to December 31, 2004, a total of 770 patients were seen, 551 (381 female and 170 male; median age, 47 years; age range, 9-89 years) who underwent initial surgical management and 219 (154 female and 65 male; median age, 44 years; age range, 5-90 years) who underwent cervical reoperation for PTC. The US images were obtained preoperatively for 486 initial and 216 reoperative patients. Therapeutic radioactive iodine was administered to 151 (68.9%) of the reoperative patients before the subsequent operation (median dose, 5.6 x 10(9) Bq; range, 7.4 x 10(8)-3.7 x 10(10) Bq). RESULTS: Ultrasonography identified nonpalpable lateral jugular LNMs in 70 (14.4%) of the patients undergoing initial exploration. Similarly, in reoperative patients, nonpalpable lateral LNMs were detected via US in 106 (64.2%), and 61 (28.2%) had LNMs detected in the central neck. Even when nodes were palpable preoperatively (37 [6.7%] of the initial and 56 [25.6%] of the reoperative patients), US assessment of the extent of LNM involvement altered the operation in 15 (40.5%) of the initial and 24 (42.9%) of the reoperative patients. The sensitivity, specificity, and positive predictive value for US were 83.5%, 97.7%, and 88.8% in initial patients, and 90.4%, 78.9%, and 93.9% in reoperative patients. CONCLUSIONS: Overall, preoperative US detected nonpalpable LNMs in 231 (32.9%) of the 702 patients with PTC who underwent US, thereby altering the operative procedure performed. In addition, even in patients with palpable LNs, US helped to guide the extent of lymphadenectomy.