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OBJECTIVE. Compared with other guidelines, the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) has decreased the number of nodules for which fine-needle aspiration is recommended. The purpose of this study was to evaluate the characteristics of malignant nodules that would not be biopsied when the ACR TI-RADS recommendations are followed. MATERIALS AND METHODS. We retrospectively reviewed a total of 3422 thyroid nodules for which a definitive cytologic diagnosis, a definitive histologic diagnosis, or both diagnoses as well as diagnostic ultrasound (US) examinations were available. All nodules were categorized using the ACR TI-RADS, and they were divided into three groups according to the recommendation received: fine-needle aspiration (group 1), follow-up US examination (group 2), or no further evaluation (group 3). RESULTS. Of the 3422 nodules, 352 were malignant. Of these, 240 nodules were assigned to group 1, whereas 72 were assigned to group 2 and 40 were included in group 3. Sixteen of the 40 malignant nodules in group 3 were 1 cm or larger, and, on the basis of analysis of the sonographic features described in the ACR TI-RADS, these nodules were classified as having one of five ACR TI-RADS risk levels (TR1-TR5), with one nodule classified as a TR1 nodule, eight as TR2 nodules, and seven as TR3 nodules. If the current recommendation of no follow-up for TR2 nodules was changed to follow-up for nodules 2.5 cm or larger, seven additional malignant nodules and 316 additional benign nodules would receive a recommendation for follow-up. If the current size threshold (1.5 cm) used to recommend US follow-up for TR3 nodules was decreased to 1.0 cm, seven additional malignant nodules and 118 additional benign nodules would receive a recommendation for follow-up. CONCLUSION. With use of the ACR TI-RADS, most malignant nodules that would not be biopsied would undergo US follow-up, would be smaller than 1 cm, or would both undergo US follow-up and be smaller than 1 cm. Adjusting size thresholds to decrease the number of missed malignant nodules that are 1 cm or larger would result in a substantial increase in the number of benign nodules undergoing follow-up. more...

Objective: The current paradigm in the treatment of patients with non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a diagnostic lobectomy rather than complete thyroidectomy and postoperative radioiodine treatment. Consequently, preoperative diagnosis of NIFTP is considered to be important., Methods: We performed the comprehensive analysis for diagnosis of preoperative 20 NIFTPs in comparison with 41 invasive encapsulated follicular papillary thyroid carcinomas (I-EFVPTCs) using the Korean Thyroid Imaging Reporting and Data System (K-TIRADS), Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), and molecular analysis for BRAF and RAS mutations., Results: K-TIRADS 3 was identified as the most common sonographic diagnosis in both NIFTP and I-EFVPTC. Unlike I-EFVPTC, K-TIRADS 5 was not identified in NIFTP. AUS/FLUS was the most common cytopathological diagnosis and none of the cases were classified as malignant category in both groups, although the difference in distribution was not significant between the groups. BRAF mutation was not found in NIFTP but was present in 9.8% of cases in I-EFVPTC. The frequency of RAS mutation in I-EFVPTCs was twice as high as that of NIFTP. Wild-type BRAF and RAS in NIFTP was significantly higher than I-EFVPTC., Conclusion: The existence of overlapping features between the groups was evident, hence conclusive distinction between radiology, cytology and molecular analysis could not be achieved. Apparently, the diagnosis of NIFTP based on comprehensive analysis was not confirmable but could perceive or at least favor the diagnosis of NIFTP., Competing Interests: The authors have declared that no competing interests exist. more...

Objective: Hürthle cell carcinomas (HCCs) of the thyroid have been recently reclassified as a separate entity due to their distinct clinical and molecular profiles. Few studies have assessed the ability of preoperative characteristics in differentiating HCCs from Hürthle cell adenomas (HCAs) due to the low prevalence of both lesions. This study aimed to compare the preoperative features of HCCs and HCAs and evaluate the diagnostic performance of ultrasound in distinguishing between both., Subjetcs and Methods: Retrospective study including 101 patients (52 HCCs and 49 HCAs) who underwent thyroid surgery from 2000 to 2016. Clinical, ultrasonographic, and histological data were reviewed. Diagnostic performance of suspicious sonographic features was analyzed in 51 cases (24 HCCs and 27 HCAs)., Results: Hürthle cell neoplasms were predominant in females. Subjects ≥ 55 years represented 58% of the cases of HCCs and 53% of those of HCAs. Carcinomas were significantly larger (p < 0.001), and a tumor size ≥ 4 cm significantly increased the risk of malignancy (odds ratio 3.67). Other clinical, cytologic, and sonographic data were similar between HCCs and HCAs. Among the HCCs, the lesions were purely solid in 54.2%, hypoechoic in 37.5%, and had coarse calcifications in 12.5%, microcalcifications in 8.3%, irregular contours in 4.2%, and a taller-than-wide shape in 16.7%. Predominantly/exclusive intranodular vascularization was observed in 52.6%. Overall, 58% of the HCCs were classified as TI-RADS 4 or 5 compared with 48% of the HCAs. TI-RADS 4 or 5 had a specificity of only 51.8% and a positive likelihood ratio of 1.21., Conclusions: Apart from the lesion size, no other preoperative feature adequately distinguished HCCs from HCAs. Sonographic characteristics raising suspicion for malignancy, which are mostly present in papillary carcinomas, were infrequent in HCCs. New tools must be developed to improve preoperative diagnosis and deferral of surgery in cases of adenomas. more...

Context: In adults, noninvasive follicular variant of papillary thyroid carcinoma (FVPTC) is considered a low risk for metastasis and persistent/recurrent disease., Objective: The goal of this study was to assess the clinical, sonographic, and histopathologic features of FVPTC in a pediatric cohort., Design: A retrospective review of subjects <19 years of age with papillary thyroid carcinoma (PTC) who underwent thyroidectomy between January 2010 and July 2015., Setting: Multidisciplinary academic referral center., Patients: Patients with FVPTC, defined as a tumor ≥1 cm in the largest dimension with predominant follicular growth, complete lack of well-formed papillae, and nuclear features of PTC., Main Outcome Measures: Tumor size and location, presence of a tumor capsule, capsule and vascular invasion, lymph node invasion, and distant metastasis., Results: Eighteen patients with FVPTC were identified from a case cohort of 110 patients with PTC. On histopathology, 13 (72%) had unifocal nodules and 14 (78%) had completely encapsulated FVPTC. Capsule invasion was frequent (nine of 14; 64%), and vascular invasion was found in one-third of patients (six of 18; 33%). No lymph node metastases were found in the 13 patients (72%) who had a central neck lymph node dissection. One patient with vascular invasion had distant metastases., Conclusion: When strictly defined, FVPTC in pediatric patients has a low risk for bilateral disease and metastasis. Prospective studies are needed to confirm whether lobectomy with surveillance is sufficient to achieve remission in pediatric patients with low-risk FVPTC. more...

Background: The noninvasive encapsulated follicular variant of papillary carcinoma (nEFVPTC) has recently been reclassified to "noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP)," removing this entity from the malignant category. This re-categorization has had major implications for clinical management. NIFTP has overlapping cytohistologic features with papillary thyroid carcinoma (PTC) and with follicular adenomas (FA), but sonographic data comparing NIFTP to PTC and FA is lacking. Our study examines the sonographic features of NIFTP as compared with PTC and FA., Methods: Ultrasound scans and Doppler blood flow from subjects who had pre-surgical sonograms and fine needle aspiration biopsies with final surgical pathology diagnoses of NIFTP/nEFVPTC, classical PTC, and FA between 01/2013-08/2016 were assessed. Sonographic and Doppler features as well as Bethesda System (TBS) diagnoses were recorded and analyzed., Results: 40 NIFTP, 58 classical PTC, and 23 FA cases were included. The most common NIFTP pre-surgical TBS cytology diagnosis was Atypia of Undetermined Significance (AUS/FLUS) (40%). NIFTP cases predominantly displayed wider-than-tall shape (100%), smooth borders (75%), occurrence in multinodular glands (82.5%), heterogeneous echogenicity (50%), both perinodular and intranodular Doppler flow patterns (70%), minimal Doppler flow grade (62.5%), and no calcifications (90%)., Conclusions: Our study demonstrates that NIFTP, PTC, and FA display several distinguishing and overlapping sonographic and Doppler features. Sonographic features appear to complement cytology findings and may help raise pre-operative concern for NIFTP in the proper clinical setting, potentially leading to a more conservative management approach., (© 2017 Wiley Periodicals, Inc.) more...

Background: This study aims to analyze changes in characteristics, practice and outcomes of pediatric differentiated thyroid cancer (DTC) at our tertiary care institution., Methods: Patients <21 years of age diagnosed between 1973 and 2013 were identified. Clinicopathological data, treatment and outcomes were obtained by a retrospective review., Results: Thirteen males and 68 females were divided into Group A (n=35, diagnosed before July 1993) and Group B (n=46, diagnosed after July 1993). Group B was more likely to undergo neck ultrasound (US) (70% vs. 23%, p<0.0001) and fine-needle aspiration (FNA) biopsy (80% vs. 26%, p<0.0001). Patients in Group B more often underwent total thyroidectomy as a definitive surgical treatment (87% vs. 69%, p=0.04). There was no difference in radioactive iodine use. Recurrence-free survival was similar., Conclusions: Increased use of US and FNA has affected initial surgical management in the latter part of the study, possibly due to extension of adult DTC guidelines. The effects of the new pediatric DTC guidelines need further study. more...

Background: Follicular variant of papillary thyroid carcinoma (FVPTC) is traditionally divided into infiltrative and encapsulated types. Adding to this classification, noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) represents a reclassification of a subset of cases (encapsulated tumors without lymphovascular or capsular invasion). The purpose of this study was to assess the role of ultrasound (US) in predicting tumor invasiveness in FVPTC., Methods: From January 2014 to May 2016, preoperative US examinations were performed on 151 patients with 152 FVPTCs who underwent surgery. Based on a pathologic analysis, the FVPTCs were categorized into three groups: NIFTP, invasive encapsulated FVPTC (iE-FVPTC), or infiltrative FVPTC (I-FVPTC). Each nodule was categorized based on the US pattern according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and the American Thyroid Association (ATA) guidelines. The correlation between tumor invasiveness and the K-TIRADS or ATA category was investigated using Spearman's rank correlation coefficient., Results: Among the 152 FVPTCs, there were 48 (31.6%) NIFTPs, 60 (39.5%) iE-FVPTCs, and 44 (28.9%) I-FVPTCs. US characteristics of the FVPTCs differed significantly according to tumor invasiveness (p ≤ 0.030). Tumor invasiveness showed a significant positive correlation with K-TIRADS (tumors of all sizes: r = 0.591, p < 0.001; tumors ≥1.0 cm: r = 0.427, p < 0.001) and ATA categories (tumors of all sizes: r = 0.532, p < 0.001; tumors ≥1.0 cm: r = 0.466, p < 0.001). According to both K-TIRADS and ATA guidelines for all-sized tumors, the most common subtype was NIFTP in low-suspicion nodules (52.6% and 51.6%), iE-FVPTC in intermediate-suspicion nodules (52.7% and 54.2%), and I-FVPTC in high-suspicion nodules (82.5% and 69.4%). After surgery, lymph node metastases were confirmed in two (4.2%) NIFTP cases, three (5.0%) iE-FVPTC cases, and eight (18.2%) I-FVPTC cases (p = 0.001). The results of the BRAF mutation analysis were not significantly different between the groups (p = 0.507)., Conclusions: Increasing tumor invasiveness from NIFTP to iE-FVPTC to I-FVPTC is positively correlated with the level of suspicion on US using both K-TIRADS and ATA guidelines. more...

A 68-year-old man underwent adjuvant radioiodine therapy for follicular variant papillary thyroid carcinoma. Post-therapeutic whole-body I scan showed abnormal radioiodine uptake on the right side of back. SPECT/CT localized this abnormal activity from a small subcutaneous lesion with fat density between the right 10th and 11th rib. Under ultrasound-guided autopsy, the lesion was confirmed as lipoma. more...

Follicular variant papillary thyroid cancer (FVPTC) is the second most common subtype after conventional PTC. We compared ultrasonographic (US) features of FVPTC to those of conventional PTC according to tumor size. We reviewed US findings, pathologic reports, and medical charts of 249 PTC patients with surgically proven disease (83 FVPTCs, 166 conventional PTCs) at our institution from January 2007 to December 2012. FVPTCs were divided into PTC-like and follicular neoplasm (FN)-like based on sonographic characteristics. PTC-like features were defined as having at least one malignant feature (taller-than-wide shape, infiltrative margin, marked hypoechogenicity, and micro-calcifications), whereas FN-like cancers showed oval solid features without malignant features. FVPTCs showed a higher rate of FN-like features than conventional PTCs. Of 166 conventional PTCs, 13 (7.8%) had FN-like features and 153 (92.2%) had PTC-like features, whereas of the 83 FVPTCs, 31 (37.3%) had FN-like features and 52 (62.7%) had PTC-like features. Macro-FVPTCs showed a higher rate of FN-like features than micro-FVPTCs (P < 0.001). Of 21 macro-FVPTCs, 18 (85.7%) had FN-like features and 3 (14.3%) had PTC-like features, whereas of the 62 micro-FVPTCs, 13 (21%) had FN-like features and 49 (79%) had PTC-like features. There were no differences in multifocality, extrathyroidal invasion, and lymph node metastasis between PTC-like FVPTCs and FN-like FVPTCs. FVPTCs showed fewer sonographic malignant features than conventional PTCs. In particular, FVPTCs larger than 1 cm had a more frequent benign sonographic appearance. Therefore, if fine-needle aspiration result is suspicious for PTC in a nodule larger than 1 cm with no suspicious US features, the possibility of FVPTC might be considered. more...

Objective: The follicular variant of papillary thyroid carcinoma (FVPTC) has multiple histological subtypes. Clinical outcomes of FVPTC are variable depending on the subtypes. This study evaluated the association of pre-operative ultrasonographic (US) findings and clinico-pathological features of FVPTC., Patients: This retrospective study enrolled patients with FVPTC (n = 70), size-matched classical variant of papillary thyroid carcinoma (CPTC, n = 328), follicular carcinoma (n = 85) and follicular adenoma (FA, n = 120). We defined the histological subtypes of FVPTC as infiltrative (I-FVPTC; n = 19) or encapsulated (E-FVPTC; n = 51) according to the presence of a fibrous capsule. Pre-operative US was reviewed using a US scoring system and classified into low US score (n = 42) and high US score (n = 28)., Results: The median US score for FVPTC was lower than CPTC (2 vs 7, P < 0·001), but higher than FA (2 vs 0, P < 0·001). The median US score for I-FVPTC was significantly higher than E-FVPTC (4 vs 2, P = 0·009). I-FVPTC was more likely to be diagnosed as a malignancy or suspicious for malignancy on cytology than E-FVPTC (P = 0·002). The cumulative risks of cervical lymph node (LN) or distant metastasis according to tumour size were significantly higher in I-FVPTC than E-FVPTC (all P < 0·001). The cumulative risks for cervical LN metastasis or capsular invasion according to tumour size were significantly higher in FVPTC with high US score than FVPTC with low US score (P = 0·005, P < 0·001, respectively)., Conclusions: Pre-operative US findings of thyroid nodules were associated with not only histological subtypes, but also the clinical behaviour in FVPTC., (© 2014 John Wiley & Sons Ltd.) more...

Objective: Follicular variant of papillary thyroid carcinoma (FVPTC) is a common variant of papillary thyroid carcinoma (PTC), but the association between BRAF mutation and the clinicopathological and ultrasonographical characteristics of FVPTC has not been well studied. The aim of this study was to determine the significance of BRAF mutation in FVPTC., Patients: The medical records of the 137 patients with >5 mm FVPTCs and known BRAF mutation status in the interested nodule were reviewed. BRAF mutation analysis was performed routinely and prospectively by Sanger sequencing. Clinicopathological and ultrasonographical characteristics were compared between BRAF mutation-positive and BRAF mutation-negative groups., Results: BRAF mutation was detected in 35 (25·5%) patients. The BRAF mutation-positive group was associated with smaller tumour size (P = 0·022), extrathyroidal extension (P = 0·001), multifocality (P = 0·046) and higher (III/IV) TNM stages (P = 0·005). In multivariable analysis, higher (III/IV) TNM stage was an independent predictive factor for BRAF mutation-positive status (adjusted OR 2·966, 95% CI 1·321-6·663). In diagnosis of FVPTC, the presence of BRAF mutation was associated with malignant features on ultrasonography (P < 0·001) and higher incidence of suspicious for malignancy or malignant diagnosis on the fine needle aspiration cytology (P = 0·023). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of US for detecting BRAF mutation were 82·9%, 57·8%, 40·3%, 90·8% and 64·2%, respectively. Conclusions BRAF mutation in FVPTC is associated with unfavourable clinicopathological characteristics and malignant features on ultrasonography and may be a potential prognostic factor as it is in classical PTC., (© 2014 John Wiley & Sons Ltd.) more...

Context: Published studies of thyroid stunning due to preablation (131)I scanning in the treatment of differentiated thyroid cancer after thyroidectomy had shown inconsistent clinical impact., Objective: The objective of the study was to evaluate the clinical outcome in patients who were given a low diagnostic (131)I activity (1.1 mCi or 40 MBq) 6 days prior to radioiodine ablation (RAI)., Design/setting: Two cohorts of patients were treated in a cancer referral center in 2004-2011. The eligibility criteria were as follows: 1) diagnosis of differentiated thyroid cancer; 2) total or near total thyroidectomy; 3) no distant metastasis; and 4) receiving 82.4 mCi or greater (3050 MBq) therapeutic (131)I activity., Patients/interventions: Three hundred five consecutive patients treated in 2004-2008 (group A) had a diagnostic activity 1.1 mCi of (131)I prior to RAI. The second cohort treated in 2009-2011 (group B) consisted of 237 patients who did not undergo diagnostic (131)I scanning prior to RAI., Main Outcome Measures: The tumor recurrence rate at 3 years and quantitative assessment using diagnostic whole-body radioiodine scans and TSH-stimulated thyroglobulin levels at 3-12 months after RAI were measured., Results: The 3-year recurrence-free survival rates were 96.4% in both groups, with 4.3% in group A and 3.4% in group B having tumor recurrence (P = .91). The ablation success rates measured by diagnostic whole-body radioiodine scans were 97.6% and 100% and by stimulated thyroglobulin were 85.3% and 85.8% in group A and B, respectively (P = .62)., Conclusions: The use of low diagnostic (131)I activity (1.1 mCi) given 6 days prior to RAI was safe and convenient without adversely affecting the long-term clinical outcome. more...

Background: Follicular variants of papillary thyroid carcinoma (FVPTCs) have dichotomous ultrasonographic (US) features. We investigated the differences in the biologic behavior of FVPTC according to US features., Methods: We reviewed the US findings, pathologic reports, and medical charts of 75 consecutive patients with FVPTC who underwent surgery at our institution from January 2006 to December 2008. FVPTCs were divided into PTC-like and follicular neoplasm (FN)-like based on US findings. PTC-like nodules were defined as having at least one accepted malignant feature (a taller-than-wide shape, an infiltrative margin, marked hypoechogenicity, and micro- or macrocalcifications), whereas FN-like nodules showed oval solid features without malignant features. The prognostic factors were compared., Results: Of the 75 FVPTCs, 42 (56%) were PTC-like and 33 (44%) were FN-like. The mean tumor size of PTC-like FVPTC was significantly smaller than that of FN-like FVPTC (p=0.0483). PTC-like FVPTC showed a significantly higher rate of multifocality than FN-like FVPTC (48% and 15% respectively; p=0.0031). Extrathyroidal extension occurred in 55% of PTC-like FVPTCs compared to 12% of FN-like FVPTCs (p=0.0001). Lymph node metastasis was more frequent in PTC-like FVPTC than in FN-like FVPTC (36% vs. 12%; p=0.0197). PTC-like FVPTC had a higher stage than FN-like FVPTC (p=0.0001). These significant factors persisted in multivariate analysis. Only one recurrence and one distant metastasis were identified, and both occurred in PTC-like FVPTC., Conclusions: FVPTC with malignant US features seems to behave in a more aggressive fashion than FVPTC without malignant US features. US can help predict the behavior of FVPTC. more...

Thyroid diseases are frequently seen in patients with acromegaly. The aim of this study is to evaluate thyroid diseases and thyroid cancer in acromegalic patients followed in a single institution. The data of 92 acromegalic (43 male, 49 female) patients followed over 12 years were retrieved retrospectively from the hospital recordings. All available data for gender, age, body weight and height, duration of acromegaly, age at diagnosis of acromegaly, treatment methods for acromegaly and history of thyroid disease, serum GH, IGF-1, thyroid function tests, thyroid ultrasonography (US), thyroid scintigraphy and thyroid fine needle aspiration biopsy (FNAB) results were recorded for the patients. The mean age of the patients was 43.9 ± 10.8 years and the mean disease duration was 12 ± 6.9 years. Thyroid US was performed in 64 patients who had nodular or diffuse goiter on palpation during the post-treatment follow-up and nodules were found in 44 (47.8 %) patients. Final diagnosis in 64 patients with thyroid US results and thyroid function tests including 26 patients with FNAB were as follows: 31 (48.4 %) benign multinodular goiter (MNG), 6 (9.4 %) simple nodular goiter, 1 (1.6 %) toxic MNG, 1 (1.6 %) Hurthle cell adenoma, and 5 (7.8 %) differentiated thyroid cancer. In addition, 9 (14.1 %) patients had diffuse goiter. One of the patients with diffuse goiter had amiodarone induced thyrotoxicosis. Eleven (17.1 %) patients had normal thyroid US and no other thyroid disease. Patients with nodules had longer disease duration than patients without nodules (14.2 ± 6.6 vs. 9.4 ± 3.4 years, p = 0.043). Thyroid volume was positively correlated with post-treatment GH and post-treatment IGF-1 levels (r = 0.309, p = 0.041 and r = 0.423, p = 0.004), respectively. We found that 7.8 % of our acromegalic patients with thyroid US results were diagnosed with thyroid cancer. Therefore, acromegalic patients must be considered as a high risk group for the development of thyroid cancer and must be closely followed for thyroid nodules and tumors. more...

Background: Follicular variant of papillary thyroid carcinoma (FV-PTC) has been increasingly diagnosed in recent years. However, little is known about its clinical behavior. The purpose of this study was to determine the disease characteristics of FV-PTC, and to compare it with classical papillary thyroid carcinoma (C-PTC) and follicular thyroid carcinoma (FTC)., Methods: All cases of C-PTC, FV-PTC, and FTC larger than 1 cm in the Surveillance, Epidemiology and End Results (SEER) Cancer Database from 1988 to 2007 were identified. Tumor behavior and patient survival were compared among these three groups. Different risk factors for disease-specific mortality in each group were evaluated by multivariate analysis., Results: More than 36,000 surgical cases were identified, including 21,796 C-PTCs, 10,740 FV-PTCs, and 3958 FTCs. Extrathyroidal extension and lymph-node metastases were more common in FV-PTC than in FTC, but significantly less common than in C-PTC (p<0.0001). Distant metastasis rates were present in 2% of patients with FV-PTC, in 1% with C-PTC, and in 4% with FTC (p<0.0001). The 10-year disease-specific survival for patients with FV-PTC was 98%, similar to C-PTC (97%) but better than FTC (94%, p<0.0001). Being over the age of 45 years remained a strong risk factor for disease-specific mortality in both FV-PTC and C-PTC, while the presence of extrathyroidal extension and distant metastases were stronger predictors of disease-specific mortality in FV-PTC than in C-PTC., Conclusions: FV-PTC is a common variant of PTC. Its clinical behavior is unique and represents an intermediate entity with clinical features that are between C-PTC and FTC. Interestingly, despite the variations in clinical behavior, the long-term outcome of these patients remains excellent and similar to C-PTC. more...

Background: The most important side effect of radioiodine ((131)I) therapy is sialoadenitis and xerostomy., Aim: To evaluate by ultrasound (US) parotid and submandibular glands after (131)I therapy for differentiated thyroid cancer (DTC)., Patients: Seventy-six subjects thyroidectomized for DTC submitted to salivary glands US examination. Forty-three of them had been previously treated with (131)I: 22 with 1.11 GBq (30 mCi) for remnant ablation, and 21 with higher doses [up to 44.4 GBq (1200 mCi)] for metastases. Thirty-three subjects studied before (131)I therapy served as controls. Parotid and submandibular volume, homogeneity, and echogenicity were determined. (131)I-treated patients filled a questionnaire about sialoadenitis symptoms., Results: Parotid gland volume was significantly higher in treated patients (28.3±16.2 ml) than in untreated patients (20.7±10.4 ml, p=0.0154) and related to the time from last (131)I therapy. Three had parotid volume <1.5 ml and complained severe xerostomy. Submandibular gland volume was similar in treated (11.2±7.6 ml) and untreated patients (8.6±4.2 ml, p=0.0602). Homogeneity and echogenicity were similar in treated and untreated patients. Sialoadenitis symptoms were reported in 26% and were related to the (131)I cumulative dose. Symptoms were not related to gland volume. Hypoechogenicity and inhomogeneity of the parotids were more frequent in patients with salivary stickiness., Conclusion: Parotid, but not submandibular, volume is increased after (131)I treatment depending on the received activity and the time from irradiation but not on sialoadenitis symptoms. Xerostomy is associated to gland atrophy at US., (©2013, Editrice Kurtis) more...

Background: Distant metastases of differentiated thyroid cancers are exceptionally localized in the soft tissues and the pelvic cavity. This last event complicates diagnosis, especially in female patients because of false positive nuclear imaging and unrelated iodine uptakes. False positive due to body secretions, urinary and fecal iodine retention and iodine uptake by non-thyroid tissues or ectopic thyroid tissue and bone metastasis of differentiated thyroid carcinoma., Methods: We present two cases of metastasectomy, guided by a peroperative gamma probe and intraoperative frozen sections of the specimens. In females patients because of potentially false positive nuclear imaging and iodine uptakes unrelated to pathology, it is very difficult to identify a pelvic metastasis. Our experience of two cases underlines these pitfalls and the possibilities to avoid them: the use of 131 Iodine SPECT/CT whole body scan, peroperative gamma probe and intraoperative frozen sections of specimen., Conclusion: Preoperative localization needs a precise 3D imaging and the surgical treatment must be guided by a peroperative gamma probe and frozen sections., (Celsius.) more...

Objective: The encapsulated follicular variant of papillary carcinoma (FVPC) was recently reported to have genetic alterations and biological behavior closer to follicular adenoma/carcinoma than classic papillary carcinoma and unencapsulated FVPC. The objective of this study is to alert cytologists to this new subtype and to report our experience., Study Design: Cytology of 41 cases of surgery-proven encapsulated FVPC was reviewed and correlated with histopathology and ultrasound findings. These cases were collected over 19 years from 188 aspirates reported as 'suspicious or atypical, cannot exclude FVPC' and from 245 aspirates reported as follicular neoplasm., Results: Thirteen aspirates had diffusely atypical nuclei, 20 aspirates had mixed normal and atypical nuclei, and 8 aspirates had no atypical nuclei. On histology, papillary nuclei were distributed focally in the second and third groups. Crowded, oval, clear nuclei occurred in nearly 80% of the cases, nuclear grooves occurred in 12.2%, and nuclear pseudoinclusions occurred in 4.9%. Capsular invasion without angioinvasion was present in 30% of encapsulated FVPCs, with angioinvasion in 17.5% and lymph node metastasis in 7.5%. Most encapsulated FVPCs were benign-appearing on ultrasound with round-to-oval, circumscribed nodules with a hypoechoic rim., Conclusions: Encapsulated FVPC is more difficult to recognize on fine-needle aspiration and ultrasound than unencapsulated FVPC., (Copyright © 2012 S. Karger AG, Basel.) more...

Diagnosis of follicular variant of papillary thyroid carcinoma (FVPTC) by ultrasound-guided fine-needle aspiration (FNA) is challenging. In this retrospective review, we evaluated triage efficacy (i.e., potential for triggering surgical intervention) in 44 archived FNA biopsies of surgically confirmed FVPTC obtained between December 2006 and December 2008. We compared the original FNA diagnoses with reclassified diagnoses based on 2007 National Cancer Institute (NCI)/Bethesda recommendations, and reviewed FNA cytologic features. Original FNA diagnoses included colloid nodule (7%, 3/44), atypical follicular cells (5%, 2/44), follicular lesion (11%, 5/44), follicular neoplasm (16%, 7/44), suspicious for malignancy/PTC (27%, 12/44), and papillary thyroid carcinoma (34%, 15/44). Reclassified diagnoses included indeterminate (5%, 2/44), colloid nodule (7%, 3/44), atypical cells of undetermined significance [ACUS] (7%, 3/44), Hurthle cell neoplasm (2%, 1/44), follicular neoplasm (7%, 3/44), suspicious for malignancy/PTC (25%, 11/44), and PTC (48%, 21/44). Triage efficacy was 77% (34/44) for original diagnoses versus 82% (36/44) for reclassified FNA diagnoses. We frequently observed cytologic features of PTC, such as nuclear grooves and fine chromatin; conversely, intranuclear inclusions, though present in 77% cases, were scant. Our review findings suggest that lack of characteristic cytologic features of PTC,coexistence with other thyroid lesions, and small tumor size arethe major obstacles to FNA diagnosis of FVPTC. Reclassification of thyroid FNA diagnoses does not significantly improve triage efficacy. Furthermore, FNA diagnoses of follicular neoplasm and suspicious for malignancy are valuable in patients with FVPTC because they trigger triage toward surgical intervention., (Copyright © 2011 Wiley Periodicals, Inc.) more...

Differentiated thyroid cancer (DTC) is usually indolent with good prognosis and long-term survival. However, DTC distant metastasis is often a grave event and accounts for most of its disease-specific mortality. The major sites of distant metastases are the lung and bone. Metastases to the brain, breast, liver, kidney, muscle, and skin are rare or relatively rare. Nevertheless, recognizing rare metastases from DTC has a significant impact on the clinical decision making and prognosis of patients. (131)I single photon emission computed tomography/computed tomography ((131)I-SPECT/CT) can provide both metabolic and anatomic information about a lesion; therefore, it can better localize and define the (131)I-WBS findings in DTC patients. In this pictorial review, the imaging features of a range of rare metastases from DTC are demonstrated, with a particular emphasis on the (131)I-SPECT/CT diagnostic aspect. more...

(131)I is given in differentiated thyroid cancer (DTC) without taking into account thyroglobulin (Tg) levels at the time of ablation, whereas 6-18 months later it is a major criterion for cure. This single-center retrospective study assessed the frequency and risk factors for persistent disease on postablation whole body scan (WBS) and postoperative neck ultrasonography (n-US) and for recurrent disease during the subsequent follow-up, in patients with DTC and undetectable TSH-stimulated Tg level (TSH-Tg) in the absence of Tg antibodies (TgAb) at the time of ablation. Among 1031 patients ablated, 242 (23%) consecutive patients were included. Persistent disease occurred in eight cases (3%) (seven abnormal WBS and one abnormal n-US), all with initial neck lymph node metastases (N1). N1 was a major risk factor for persistent disease. Among 203 patients with normal WBS and a follow-up over 6 months, TSH-Tg 6-18 months after ablation was undetectable in the absence of TgAb in 173 patients, undetectable with TgAb in 1 patient and equal to 1.2  ng/ml in 1 patient. n-US was normal in 152 patients and falsely positive in 3 patients. After a mean follow-up of 4 years, recurrence occurred in two cases (1%), both with aggressive histological variants. The only risk factor for recurrence was an aggressive histological variant (P = 0.03). In conclusion, undetectable postoperative TSH-Tg in the absence of TgAb at the time of ablation is frequent. In these patients, repeating TSH-Tg 6-18 months after ablation is not useful. (131)I ablation could be avoided in the absence of N1 and aggressive histological variant. more...

The risk of malignancy in a "hot" thyroid nodule detected by radioiodine scintigraphy is rare. We report a case of a 63-year-old man with a hyperfunctioning nodule demonstrated by radioiodine scintigraphy and cytology suspicious for follicular variant of papillary thyroid carcinoma (FVPTC). There were no locoregional or distant metastases at initial diagnosis. Histopathologic examination following thyroidectomy confirmed the presence of an encapsulated FVPTC. A year into follow-up, his I-131 whole body scan performed following the withdrawal from exogenous thyroid hormone was negative, whereas his serum thyroglobulin (Tg) levels were intermediate. A subsequent PET/CT scan revealed a small, but stable, metabolically active pretracheal lymph node, which on biopsy was confirmed to be stage III FVPTC. In conclusion, the presence of hyperfunctioning thyroid nodule(s) does not preclude malignancy and, therefore, proper cytohistologic evaluation in such patients may help to exclude a coexistent thyroid carcinoma. Patients treated for localized PTC may benefit from serial PET/CT follow-up in the early detection and management of recurrence or distant metastases. more...

Objective: The objective of this study was to determine whether the use of recombinant human TSH (rhTSH) to stimulate radioiodine uptake after thyroidectomy is as efficacious as a period of withholding thyroid hormones, while at the same time avoiding hypothyroidism, reducing sick leave time and shortening the hospital stay., Design: Our aim was to compare the standard procedure of differentiated thyroid cancer treatment, which consists of thyroidectomy followed by 4 weeks of hypothyroidism and a conclusive ablative activity of (131)iodine, with a new shortened treatment in which l-thyroxine (T(4)) medication is initiated a day after thyroidectomy, followed by application of rhTSH stimulation and subsequent ablation a few days after surgery. We presumed our treatment to represent the most sophisticated strategy for the reduction in sick leave days overall without any reduction in safety or the efficacy of ablative therapy., Methods: Patients (n=25) were randomized either for surgery and rhTSH stimulation or surgery and l-T(4) abstinence before the first application of radioiodine. Ablation success was determined by neck ultrasound and serum thyroglobulin during follow-up. RhTSH receivers were monitored for an average of 635 days (s.d.+/-289) and patients in l-T(4) abstinence for an average of 624 days (s.d.+/-205). Both groups were statistically compared for significant differences in treatment efficacy, safety and overall time of sick leave., Results and Conclusions: Our shortened treatment proved to be equally efficacious and safe in comparison with the conventional therapy regimen. At the same time, it showed economic advantages through the reduction in average sick leave time from approximately 29 days (l-T(4) abstinence) down to approximately 6 days (rhTSH stimulation) as well as sustaining the patient's quality of life by the complete avoidance of hypothyroidism. more...

Introduction: Certain surgeon-performed ultrasound (SUS) features may predict differentiated thyroid cancer (DTC). The purpose of this study was to determine the SUS characteristics that are strongly associated with DTC in patients with solitary thyroid nodules., Methods: A retrospective review of 115 patients with solitary thyroid nodules who had SUS before thyroid surgery was performed. Patients were subdivided into two groups based on final pathology results: patients with DTC(n=61) and those with benign disease (BD) (n=54). SUS characteristics of thyroid nodules were studied, including size, type, calcifications, borders, shape, and echogenicity. For SUS features, odds ratio (OR), confidence interval (CI), and P values are presented., Results: Of 115 operated patients with solitary thyroid nodules, 53% (61/115) had DTC [papillary, 59%; follicular variant/papillary, 34%; Hürthle cell, 5%; and follicular, 2%] and 47% (54/115) had BD [hyperplastic, 56%; follicular adenoma, 31%; lymphocytic thyroiditis, 7%; and Hürthle cell adenoma, 6%]. Univariate analysis showed that hypoechogenicity, irregular borders, and microcalcifications were associated with an increased risk for DTC compared to hyper/isoechogenicity, regular borders, and coarse/no calcifications. Association strength was confirmed using a multivariate model, including the five SUS characteristics. Hypoechogenicity (OR=4.27; 95% CI, 1.74-10.47; P<0.002), irregular borders (OR=3.10; 95% CI, 1.25-7.7; P<0.015), and microcalcifications (OR=2.65; 95%CI, 1.04-6.76; P<0.05) had a greater association with DTC after adjustment for the other four SUS features. Additionally, the combination of hypoechogenicity, irregular borders, and microcalcifications had the strongest association with DTC (OR=30.1; 95% CI, 7.76-119.2; P<0.0001)., Conclusions: Hypoechogenicity, irregular borders, and microcalcifications were most strongly associated with an increased risk for DTC. These SUS characteristics may have additional clinical value in predicting DTC in patients with solitary thyroid nodules. more...

Patients with poorly differentiated thyroid cancers (PDTC), anaplastic thyroid cancers (ATC), and radioactive iodine-refractory (RAIR) differentiated thyroid cancers have a high mortality, particularly if positive on [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET). To obtain comprehensive genetic information on advanced thyroid cancers, we designed an assay panel for mass spectrometry genotyping encompassing the most significant oncogenes in this disease: 111 mutations in RET, BRAF, NRAS, HRAS, KRAS, PIK3CA, AKT1, and other related genes were surveyed in 31 cell lines, 52 primary tumors (34 PDTC and 18 ATC), and 55 RAIR, FDG-PET-positive recurrences and metastases (nodal and distant) from 42 patients. RAS mutations were more prevalent than BRAF (44 versus 12%; P = 0.002) in primary PDTC, whereas BRAF was more common than RAS (39 versus 13%; P = 0.04) in PET-positive metastatic PDTC. BRAF mutations were highly prevalent in ATC (44%) and in metastatic tumors from RAIR PTC patients (95%). Among patients with multiple metastases, 9 of 10 showed between-sample concordance for BRAF or RAS mutations. By contrast, 5 of 6 patients were discordant for mutations of PIK3CA or AKT1. AKT1&#95;G49A was found in 9 specimens, exclusively in metastases. This is the first documentation of AKT1 mutation in thyroid cancer. Thus, RAIR, FDG-PET-positive metastases are enriched for BRAF mutations. If BRAF is mutated in the primary, it is likely that the metastases will harbor the defect. By contrast, absence of PIK3CA/AKT1 mutations in one specimen may not reflect the status at other sites because these mutations arise during progression, an important consideration for therapies directed at phosphoinositide 3-kinase effectors. more...

Objective: To evaluate the effectiveness of gamma probe performed with technetium Tc 99m-labeled pertechnetate in patients who underwent completion thyroidectomy after pathologic detection of incidental thyroid cancer following subtotal thyroidectomy., Methods: In this prospective study, we evaluated findings from patients with multinodular goiter who underwent gamma probe-guided lateral approach completion thyroidectomy after the pathologic detection of incidental thyroid cancer following subtotal thyroidectomy where partial thyroid tissue was left unilaterally or bilaterally. Patients who underwent the procedure between January 2003 and January 2007 were included. Thyroid scintigraphy; thyroid and neck ultrasonography examinations; and concentrations of thyroid hormones, thyrotropin (TSH), thyroglobulin, and thyroglobulin antibodies were evaluated before the second operation. Patients were administered 3 mCi technetium Tc 99m pertechnetate during anaesthetic induction, and we extracted suspicious thyroid tissue and tissue with activity above background activity levels according to gamma probe. Extracted tissues were evaluated pathologically., Results: Completion thyroidectomy was performed in 23 patients. Seventy-nine tissue samples were extracted; 49 were thyroid tissue and 30 were nonthyroid tissue. Mean thyroid tissue to background activity ratio (T:B) was 6.4 +/- 3.9 (range, 2-14.3), and mean thyroid bed (after excision) to background activity ratio (Tbed:B) was 1.2 +/- 0.2 (range, 0.8-1.7) (P = .001). Mean T:B and Tbed:B ratios of the nonthyroid tissue were 1.2 +/- 0.3 (range, 0.2-1.7) and 1.1 +/- 0.2 (range, 0.4-1.4), respectively (P = .001). The thyroid tissue T:B ratio was significantly higher than that of non-thyroid tissue (P<.001). Gamma probe labeling contributed to extraction of small amounts of thyroid tissue that could not be viewed by scintigraphy in 43% of patients., Conclusions: Using gamma labeling, thyroid tissue shows significantly more activity than nonthyroid tissue. Gamma probe helps detect small, residual thyroid tissue that is buried in the scar tissue that cannot be distinguished by scintigraphy; therefore, it assists in the extraction of the maximum amount of thyroid tissue. more...

Background: Retinoic acid (RA) treatment has been used for redifferentiation of metastatic thyroid neoplasia that have lost radioiodine (131I) uptake with heterogeneous results., Aim: Retrospective analysis of the recovery rate of 131I uptake after RA treatment in patients from 11 Spanish hospitals., Methods: Twenty-seven patients (14 men, 13 women) with papillary [21], follicular [4], and oncocytic [2] thyroid cancer initially treated with total thyroidectomy plus 131I, and with 131I negative metastatic disease, were given 13-cis RA (0.66-1.5 mg/kg for 5-12 weeks) followed by a therapeutic 131I dose (3700-7400 MBq); 3 months later thyroglobulin levels and computed tomography imaging were performed., Results: In 9 out 27 cases (33%) (8 papillary, 1 follicular) optimal positive 131I scan was observed after RA treatment; in the remaining 18, 10 had a suboptimal uptake (7 papillary, 2 follicular, 1 oncocytic) and in the rest there was no 131I uptake recovery (6 papillary, 1 follicular, 1 oncocytic). In 17 positive responses to RA (either optimal or suboptimal) in which image follow-up was available, decrease or stabilization of metastatic growth was observed in 7, while tumor mass increased at short term in the remaining 10. No major side effects were detected., Conclusion: Quite a high rate of 131I uptake recovery after RA treatment may be obtained in advanced differentiated thyroid cancer, but the potential modification of the natural course of the disease is uncertain. A better biological characterization of these tumors allowing the identification of potential responders to RA may improve the outcome of RA coadjuvant therapy. more...

Unlabelled: Thyroglobulin (Tg) is a specific marker of residual thyroid cancer or tumor recurrence. In patients with elevated Tg levels and negative diagnostic radioiodine (131I) whole-body scans (dWBS), administration of a therapy dose may reveal foci that were not initially apparent. The aim of this study was to identify factors, other than 131I activity, which might explain why a post-therapy 131I whole-body scan is sometimes positive despite a negative dWBS., Patients and Methods: We reviewed data on all patients with elevated Tg levels and negative dWBS with 185 MBq 131I off-T4 at followup, who subsequently received an empiric therapy dose of 3700 MBq of 131I. During a 5-yr period, 22 patients met these criteria. 131I therapy could be given immediately after negative dWBS in 9 patients, with an average of 8 extra days of hypothyroidism. In the other 13 patients, therapy was given an average of 8 months later., Results: The therapy scan was negative in 16 patients, while it showed uptake in the thyroid bed in 5 patients and distant metastases in two. In the latter two patients, the TSH level was suboptimal at the time of dWBS (9 and 25 microIU/ml), and had risen to 34 and 70 microIU/ml respectively at the time of therapy. Overall, a positive scan following therapy occurred in 7 patients (6/9 patients treated immediately and 1/13 patients treated in a separate setting; p<0.01). In patients with positive therapy scans, the mean TSH level was 73 microIU/ml at the time of dWBS and 103.5 microIU/ml at the time of therapy (41% increase; p<0.05). In patients with negative therapy scans the mean TSH level was 84 microIU/ml at dWBS and 86 microIU/ml at the time of the therapy scan (2% increase)., Conclusions: Our study suggests that interval increase in TSH level with a longer period of stimulation may have contributed to making the whole-body scan positive at the time of therapy. Nowadays, patients with elevated Tg are directly given a therapy dose of 131I. Special care should be taken when preparing patients who have been on suppressive levothyroxine therapy for a long time, in order to avoid misclassifying the tumor as non-functioning. more...

A 60-year-old woman consulted a medical specialist for numbness of the chin. A bilateral mental nerve affection was found. A PET-scan with fluodeoxyglucose revealed a localised process in the right thyroid gland. She was operated for a localised thyroid cancer. At follow-up, 6 years later, she was in good health without any symptoms apart from numbness of the chin. more...

Background: Certain ultrasound features can predict malignancy in patients with thyroid nodules. The purpose of this study was to determine the value of surgeon-performed ultrasound (SUS) in predicting thyroid malignancy in patients with indeterminate fine-needle aspiration (FNA) cytology., Methods: 477 consecutive patients with dominant thyroid nodules were referred to our institution from 2002 to 2007. Of these, 180/477(38%) were judged to have indeterminate cytology: follicular neoplasm (FN, n = 108), Hürthle neoplasm (HN, n = 29), and suspicious for papillary thyroid cancer (SPTC, n = 43). SUS characteristics for thyroid nodules were recorded in a prospective database prior to thyroidectomy. Variables analyzed included patients' age and sex, nodule size, shape, echogenicity, consistency, borders, multiplicity/multicentricity, and presence of microcalcifications. SUS features of thyroid nodules were correlated with final pathology. The accuracy of individual SUS features as well as the presence of two or more adverse features in predicting malignancy was also examined., Results: There were 144 females and 36 males. Mean age was 52 years (range 17-87 years). Mean tumor size was 2.7 cm (range 0.65-6.6 cm). Overall, final pathology revealed cancer in 92/180 (51%) patients. Malignancy was present in 40/108 (37%) FN, 12/29 (41%) HN, and 40/43 (93%) SPTC. Nodule borders (irregular), shape (height > width), hypoechogenicity, and presence of microcalcifications were significantly associated with malignancy. The presence of 2 or >/=3 adverse SUS thyroid nodule features was associated with a >/=55% or >/=78% risk of malignancy, respectively., Conclusion: Adverse thyroid nodule features seen on SUS may predict malignancy and help determine the initial extent of thyroidectomy in patients with indeterminate FNA cytology. more...

Context: One year after initial treatment, low-risk differentiated thyroid cancer (DTC) patients undergo recombinant human (rh)TSH-stimulated serum thyroglobulin (Tg) (rhTSH-Tg) and neck ultrasound (US)., Objective: The need for more rhTSH-Tg in these patients is controversial. We evaluated the utility of a second rhTSH-Tg in DTC patients 2-3 yr after their first evaluation., Results: At the first rhTSH-Tg, basal and stimulated serum Tg was undetectable in 68 of 85 patients. Neck US was unremarkable in all but one, who had evidence of lymph node disease. Seventeen of 85 patients had undetectable serum Tg that became positive after rhTSH, with negative imaging in 10 and evidence of disease in seven. Patients with no evidence of disease were reevaluated 2-3 yr later (second rhTSH-Tg). In patients in which the first stimulated Tg was undetectable, all had undetectable basal serum Tg, which remained undetectable after rhTSH in 66 of 67 patients (98.5%) and became detectable in one (1.5%) (positive neck US). In the 10 patients with detectable stimulated Tg in the first test, basal serum Tg and US were negative at the second test, but rhTSH-Tg became detectable in six. Compared with the first rhTSH-Tg, the second stimulated Tg in these six patients decreased in one, increased in three, and stabilized in two patients., Conclusions: The second rhTSH-Tg was informative in patients who had first stimulated Tg detectable but not in those who had undetectable Tg at the first test, in which the only patient with recurrence was diagnosed by neck US. Thus, rhTSH-Tg should be repeated only in patients who have had a positive first rhTSH-Tg and negative imaging. more...

Background: Serum thyroglobulin (Tg) is the marker of differentiated thyroid cancer after initial treatment and TSH stimulation increases its sensitivity for the diagnosis of recurrent disease., Aim: The goal of the study is to compare the diagnostic values of seven methods for serum Tg measurement for detecting recurrent disease both during L-T4 treatment and after TSH stimulation., Methods: Thyroid cancer patients who had no evidence of persistent disease after initial treatment (total thyroidectomy and radioiodine ablation) were studied at 3 months on L-T4 treatment (Tg1) and then at 9-12 months after withdrawal or recombinant human TSH stimulation (Tg2). Sera with anti-Tg antibodies or with an abnormal recovery test result were excluded from Tg analysis with the corresponding assay. The results of serum Tg determination were compared to the clinical status of the patient at the end of follow-up., Results: Thirty recurrences were detected among 944 patients. A control 131I total body scan had a low sensitivity, a low specificity, and a low clinical impact. Assuming a common cutoff for all Tg assays at 0.9 ng/ml, sensitivity ranged from 19-40% and 68-76% and specificity ranged from 92-97% and 81-91% for Tg 1 and Tg2, respectively. Using assays with a functional sensitivity at 0.2-0.3 ng/ml, sensitivity was 54-63% and specificity was 89% for Tg1. Using the two methods with a lowest functional sensitivity at 0.02 and 0.11 ng/ml resulted in a higher sensitivity for Tg1 (81% and 78%), but at the expense of a loss of specificity (42% and 63%); finally, for these two methods, using an optimized functional sensitivity according to receiver operating characteristic curves at 0.22 and 0.27 ng/ml resulted in a sensitivity at 65% and specificity at 85-87% for Tg1., Conclusion: Using an assay with a lower functional sensitivity may give an earlier indication of the presence of Tg in the serum on L-T4 treatment and may be used to study the trend in serum Tg without performing any TSH stimulation. Serum Tg determination obtained after TSH stimulation still permits a more reliable assessment of cure and patient's reassurance. more...

Objective: 2-Deoxy-2-[F-18]fluoro-D-glucose positron emission tomography (FDG-PET) has an established role in restaging of various cancers, including papillary and undifferentiated thyroid carcinoma, but detection rates are variable in the published literature. We were therefore prompted to review our experience with FDG-PET in detection of recurrent papillary thyroid cancer (PTC)., Methods: This is a retrospective study (April 1, 1995-March 31, 2005) of 21 patients with histologic diagnosis of PTC who had PET examinations. The group included seven men and 14 women, with age range of 26-75 years (average 50 +/- 16). The PET scan request was triggered by rising levels of thyroglobulin (Tg) in the presence of a negative iodine-131 scan., Results: Recurrent/metastatic disease was identified by PET in 16 (76%) of the 21 patients with PTC. The sensitivity and specificity of FDG-PET for disease detection in this cohort were 88.2% [95% confidence interval (CI), 65.7-96.7] and 75% (95% CI, 30.1-95.4), respectively. The Tg levels were 1.0-10.4 ng/ml (average, 4.52 ng/ml) in the patients with negative PET scans and 1.0-38 ng/ml (average, 16.8 ng/ml) in patients with positive scans. The lesions were located in the cervical lymph nodes (8), thyroid bed (4), lungs (4), and mediastinal lymph nodes (2)., Conclusion: Our study confirms the feasibility of PET in detection of residual/recurrence of PTC, with sensitivity of 88.2% (95% CI, 65.7-96.7) and specificity of 75% (95% CI, 30.1-95.4). Detectable levels of Tg, even in the presence of negative I-131 scan or anatomic imaging, should prompt restaging with FDG-PET. more...

Context/objective: Approximately 15% of thyroid cancer patients develop subsequent metastases. The clinical course of patients with metastatic thyroid carcinoma is highly variable. We hypothesized that the metabolic activity of metastatic lesions, as defined by retention of 2-[(18)F]fluoro-2-deoxyglucose (FDG), would correlate with prognosis., Design/patients: The initial FDG-positron emission tomography (PET) scans from 400 thyroid cancer patients were retrospectively reviewed and compared with overall survival (median follow-up, 7.9 yr). We examined the prognostic value of clinical information such as gender, age, serum thyroglobulin, American Joint Committee on Cancer (AJCC) stage, histology, radioiodine avidity, FDG-PET positivity, number of FDG-avid lesions, and the glycolytic rate of the most active lesion., Results: Age, initial stage, histology, thyroglobulin, radioiodine uptake, and PET outcomes all correlated with survival by univariate analysis. However, only age and PET results continued to be strong predictors of survival under multivariate analysis. The initial American Joint Committee on Cancer stage was not a significant predictor of survival by multivariate analysis. There were significant inverse relationships between survival and both the glycolytic rate of the most active lesion and the number of FDG-avid lesions., Conclusions: FDG-PET scanning is a simple, expensive, but powerful means to restage thyroid cancer patients who develop subsequent metastases, assigning them to groups that are either at low (FDG negative) or high (FDG positive) risk of cancer-associated mortality. We propose that the aggressiveness of therapy for metastases should match the FDG-PET status. more...

Rationale and Objectives: The effectiveness of 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) and technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) of neck and chest was evaluated to detect metastatic lesions in well-differentiated thyroid carcinoma after nearly total thyroidectomy and radioiodine (I-131) treatment who present with elevated serum human thyroglobulin levels but negative I-131 whole body scan., Materials and Methods: Twenty-three patients with differentiated thyroid carcinoma who underwent nearly total thyroidectomy and I-131 treatments were included in this study., Results: All of the 23 patients had negative I-131 whole body scan and elevated human thyroglobulin levels under thyroid-stimulating hormone stimulation. Metastatic lesions were detected by FDG-PET in 20 patients, while Tc-99m TF SPECT revealed metastatic lesions in only 11 of the 20 patients. Both FDG-PET and Tc-99m TF SPECT failed to demonstrate miliary pulmonary metastases in two of the remaining three patients. The other patient did not show any lesion on FDG-PET, Tc-99m TF SPECT, chest computed tomography, or other imaging techniques., Conclusion: This study demonstrated that FDG-PET is more sensitive than Tc-99m TF SPECT to detect metastatic lesions in differentiated thyroid carcinoma with elevated human thyroglobulin but negative I-131 whole body scan. However, miliary pulmonary metastases could be missed by the both techniques. more...