Fractionated dosage of radioiodine for the ablation of low-risk differentiated thyroid cancer has no impact on survival.

INTRODUCTION: Due to a limited number of hospital beds dedicated to radioiodine therapy (RIT) in some countries, a fractionated dose of radioiodine may be considered as the ablation therapy of differentiated thyroid cancer (DTC). The aim of the study was to compare the late effects of ablation therapy with single and fractionated dose of radioiodine in patients with DTC. PATIENTS AND METHODS: Patients with low-risk DTC referred to our institution 5-16 weeks after thyroidectomy, treated with 2.2 GBq of 131I, either in a single dose (2.2 GBq, group 1) or in two fractions (1.1 GBq+1.1 GBq administered with a 24 h interval, group 2) were retrospectively included. Clinical outcome of the treatment and overall survival (OS) was evaluated. RESULTS: 83 patients treated with single dose and 186 patients treated with fractionated dose of radioiodine were included. Mean duration of follow-up was 8.0 vs.7.8 years, respectively (p=ns). There were no significant differences between the groups in male to female ratio, age at the time of the first RIT, proportion of papillary thyroid cancers, volume of the thyroid tissue, thyroid-stimulating hormone and thyroglobulin levels before first RIT. RIT was repeated in 55.4% and 54.8% of patients from group 1 and 2 respectively (p=ns). There were no significant differences including the course and outcomes of the treatment between the groups, measured by: cumulative dose of 131I, mean number of 131I administrations and mean thyreoglobulin concentration at the follow-up. Also the overall survival did not differ significantly between the groups. Probability of 5-year OS was 98.6% for patients treated with single and 99.5% with fractionated dose of 131-I, 10 year OS - 98.6 and 97.1% respectively, 15 year OS - 95.5 and 92.9% respectively (p=ns). CONCLUSIONS: In the long-term follow-up, radioiodine ablation therapy with fractionated doses in low-risk DTC patients is equally effective as with single dose. < p > < /p >.

Sonographic features of medullary thyroid carcinomas--a systematic review and meta-analysis.

INTRODUCTION: Thyroid nodular goitre is one of the most common endocrine disorders. Differentiating between benign and malignant lesions is an emerging challenge in endocrinological practice. Ultrasonography (US) remains the most commonly applied method in the preliminary assessment of lesions and is the basis for the decision as to fine needle aspiration biopsy (FNAB) and further diagnostics. Many studies have evaluated the diagnostic value of US malignancy features. However, they focused mainly on papillary thyroid cancer (PTC). It remains unclear whether other types of thyroid carcinoma (TC) are also characterised by the same US features. The aim of this study was to assess the usefulness of US features considered as markers in the diagnosis of medullary thyroid cancer (MTC). MATERIAL AND METHODS: The PubMed/MEDLINE and Cochrane Library databases were searched to identify studies on US features of MTCs. The random-effects model was used to calculate pooled sensitivity and specificity and odds ratios (OR) - if a comparison with PTCs was available. RESULTS: Hypoechogenicity was present in 83.4% of MTCs, and 32.7% were markedly hypoechogenic. None of the 157 MTCs was hyperechogenic. Sensitivity of halo absence was 88.9%, but irregular margins were present in 38.0%. 35.5% of MTCs had microcalcifications, and 27.0% had macrocalcifications. 14.4% presented 'taller than wide feature' (higher anteroposterior than transverse diameter). Apart from macrocalcifications, all these features occurred insignificantly less often in MTCs than in PTCs. CONCLUSIONS: US features commonly considered as markers of malignancy can be useful also in the diagnostics of MTCs. However, MTCs tend to possess suspicious US features slightly less often than PTCs. Some features, such as hyperechogenicity, can be considered to be strong markers of benign status. Although the US appearance of the thyroid lesion is an important diagnostic factor, it is worth remembering that it does not allow for a definitive differentiation between benign and malignant nodules. In the case of MTCs, as well as other TCs, US examination remains a valuable diagnostic tool, but should always be interpreted carefully in the context of other examinations.

How to select nodules for fine-needle aspiration biopsy in multinodular goitre. Role of conventional ultrasonography and shear wave elastography - a preliminary study.

INTRODUCTION: The wide prevalence and relatively low malignancy ratio of thyroid nodular disease (TND) make the selection of suspicious lesions for fine-needle aspiration biopsy (FNAB) a vital problem in endocrinology. Apart from the decision as to whether FNAB is necessary, there is often a second problem - which nodule or nodules to choose in a case of multinodular goitre (MNG), when the number of lesions may be high. The aim of this study was to compare the usefulness of conventional ultrasonography (US) to that of a novel method of tissue stiffness assessment - shear wave elastography (SWE) - in differentiating between malignant and benign nodules and in selecting the most suspicious lesions in MNG. MATERIAL AND METHODS: Patients with MNG, referred for thyroidectomy irrespectively of indications for surgery, underwent thyroid US and SWE examination before surgery, between August and December 2010. Results of these examinations were correlated with the histopathological outcomes. RESULTS: 80 patients with 339 thyroid nodules were included. Ten thyroid cancers (TCs) in ten patients were diagnosed in histopathology. All ten cancers were the least elastic lesions in MNG (using quantitative data on maximal tissue stiffness). Four cancers appeared as the biggest lesions in MNG, while one was equally the biggest in a particular goitre (there were other lesions of the same size) taking into account maximal diameter. Three of ten cancers possessed the highest number of suspicious features in MNG, a further four had the highest number equally, with at least one other lesion in the same goitre. CONCLUSIONS: On the basis of our results, the relatively high stiffness of a lesion compared to other nodules from the same MNG should be considered as a strong argument for choosing that particular one for FNAB.

Comparison of diagnostic value of conventional ultrasonography and shear wave elastography in the prediction of thyroid lesions malignancy.

INTRODUCTION: Thyroid nodular disease (TND) is a very common disorder. However, since the rate of malignancy is reported to be 3-10%, only a minority of patients require aggressive surgical treatment. As a result, there is a need for diagnostic tools which would allow for a reliable differentiation between benign and malignant nodules. Although a number of conventional ultrasonographic (US) features are proved to be markers of malignancy, Shear Wave Elastography (SWE) is considered to be an improvement of conventional US. The aim of this study was to compare conventional US markers and SWE diagnostic values in the differentiation of benign and malignant thyroid nodules. MATERIALS AND METHODS: All patients referred for thyroidectomy, irrespective of the indications, underwent a US thyroid examination prospectively. Patients with TND were included into the study. Results of the US and SWE examinations were compared with post-surgical histopathology. RESULTS: One hundred and twenty two patients with 393 thyroid nodules were included into the study. Twenty two patients were diagnosed with cancer. SWE turned out to be a predictor of malignancy superior to any other conventional US markers (OR=54.5 using qualitative scales and 40.8 using quantitative data on maximal stiffness with a threshold of 50 kPa). CONCLUSIONS: Although most conventional US markers of malignancy prove to be significant, none of them are characterized by both high sensitivity and specificity. SWE seems to be an important step forward, allowing for a more reliable distinction of benign and malignant thyroid nodules. Our study, assessing SWE properties on the highest number of thyroid lesions at the time of publication, confirms the high diagnostic value of this technique. It also indicates that a quantitative evaluation of thyroid lesions is not superior to simpler qualitative methods.