Controversies and challenges in the management of well-differentiated thyroid cancer

Investigating the prevalence of risk factors of papillary thyroid carcinoma recurrence and disease-free survival after thyroidectomy and central neck dissection in Iranian patients

Background: Papillary thyroid carcinoma (PTC) is considered the most frequent thyroid malignancy (85-90%) with a good prognosis. However, its frequent recurrence increases mortality and morbidity. In this inquiry we investigated the prevalence of risk factors of PTC recurrence and disease free survival after thyroidectomy and central neck dissection. Method: In this retrospective study, all patients with confirmed PTC who underwent total thyroidectomy and central neck dissection in Imam Reza and Omid hospitals of Mashhad University of Medical Sciences from 2004 to 2011 were included. Total locoregional and distant recurrence rate, 5-year disease free survival rate (DFS) and contributing factors of recurrence were investigated after at least 5 years. Results: In this study 289 patients were included with a mean follow-up of 72.90 ± 11.02 months. 70.6% were female and 29.4% were male. Recurrence occurred in 58 cases from which 10 were distant and 48 were loco-regional. 5-year DFS was 80% and total-survival-rate was 99%. Our analysis showed that primary tumor size, vascular-invasion, extra-thyroid extension, and lymph node ratio (LNR) were significantly related to DFS.

Thyroid Remnant Estimation by Diagnostic Dose (131)I Scintigraphy or (99m)TcO4(-) Scintigraphy after Thyroidectomy: A Comparison with Therapeutic Dose (131)I Imaging

In this clinical study, we have compared routine diagnostic dose ¹³¹I scan and ^99mTcO₄⁻ thyroid scintigraphy with therapeutic dose ¹³¹I imaging for accurate thyroid remnant estimation after total thyroidectomy. We conducted a retrospective review of the patients undergoing total thyroidectomy for differentiated thyroid carcinoma (DTC) and subsequently receiving radioactive iodine (RAI) treatment to ablate remnant thyroid tissue. All patients had therapeutic dose RAI whole body scan, which was compared with that of diagnostic dose RAI, ^99mTcO₄⁻ thyroid scan, and ultrasound examination. We concluded that therapeutic dose RAI scan reveals some extent thyroid remnant in all DTC patients following total thyroidectomy. Diagnostic RAI scan is much superior to ultrasound and ^99mTcO₄⁻ thyroid scan for the postoperative estimation of thyroid remnant. Ultrasound and ^99mTcO₄⁻ thyroid scan provide little information for thyroid remnant estimation and, therefore, would not replace diagnostic RAI scan.