BACKGROUND:To examine the applicability of the "taller than wide" (ttw) criterium for risk assessment of thyroid nodules (TNs) in primary/secondary care units and the role of thyroid scintigraphy therein. METHODS:German bicenter study performed in a setting of primary/secondary care. Patient recruitment and analysis in center A was conducted in a prospective manner. In center B, patient data were retrieved from a database that was originally generated by prospective data collection. TNs were assessed by ultrasound and thyroid scans, mostly fine needle biopsy and occasionally surgery and others. In center A, only patients who presented for the first time were included. The inclusion criterion was any TN ≥ 10 mm that had at least the following two sonographic risk features: solidity and a ttw shape. In center B, consecutive patients who had at least ttw and hypofunctioning nodules ≥ 10 mm were retrieved from the above-mentioned database. The risk of malignancy was determined according to a mixed reference standard and compared with literature data. RESULTS:In center A, 223 patients with 259 TNs were included into the study. For further analysis, 200 nodules with a reference standard were available. The overall malignancy rate was 2.5% (upper limit of the 95% CI: 5.1%). After the exclusion of scintigraphically hyperfunctioning nodules, the malignancy rate increased slightly to 2.8% (upper limit of the 95% CI: 5.7%). Malignant nodules exhibited sonographic risk features additional to solidity and ttw shape more often than benign ones. In addition to the exclusion of hyperfunctioning nodules, when considering only nodules without additional US risk features, i.e., exclusively solid and ttw-nodules, the malignancy rate decreased to 0.9% (upper limit 95% CI: 3.7%). In center B, from 58 patients, 58 ttw and hypofunctioning TNs on thyroid scans with a reference standard were available. Malignant nodules from center B were always solid and hypoechoic. The overall malignancy rate of hypofunctioning and ttw nodules was 21%, with the lower limit of the 95% CI (one-sided) being 12%. CONCLUSIONS:In primary/secondary care units, the lowest TIRADS categories for indicating FNB, e.g., applying one out of five sonographic risk features, may not be appropriate owing to the much lower a priori malignancy risk in TNs compared to tertiary/quaternary care units. Even the combination of two sonographic risk features, "solidity" and "ttw", may only be appropriate in a limited fashion. In contrast, the preselection of TNs according to hypofunctioning findings on thyroid scans clearly warranted FNB, even when applying only one sonographic risk criterion ("ttw"). For this reason, thyroid scans in TNs may not only be indicated to rule out hyperfunctioning nodules from FNB but also to rule in hypofunctioning ones.

Abstract Purpose  To evaluate the recommendations for or against fine needle biopsy (FNB) of hypofunctioning thyroid nodules (TNs) using of five different Ultrasound (US) -based risk stratification systems (RSSs). Methods  German multicenter study with 563 TNs (≥ 10 mm) in 534 patients who underwent thyroid US and surgery. All TNs were evaluated with ACR TI-RADS, EU-TIRADS, ATA, K-TIRADS 2016 and modified K-TIRADS 2021. A correct recommendation was defined as: malignant TN with recommendation for FNB (appropriate) or benign TN without recommendation for FNB (avoided). An incorrect recommendation was defined as: malignant TN without recommendation for FNB (missed) or benign TN with recommendation for FNB (unnecessary). Results  ACR TI-RADS demonstrated the highest rate of correct (42.3 %) and lowest rate of incorrect recommendations (57.7 %). The other RRSs showed similar results for correct (26.5 %–35.7 %) and incorrect (64.3 %–73.5 %) recommendations. ACR TI-RADS demonstrated the lowest rate of unnecessary (73.4 %) and the highest rate of appropriate (26.6 %) FNB recommendation. For other RSSs, the rates of unnecessary and appropriate FNB were between 75.2 %–77.1 % and 22.9 %–24.8 %. The lowest rate of missed FNB (14.7 %) and the highest rate of avoided FNB (85.3 %) was found for ACR TI-RADS. For the other RSSs, the rates of missed and avoided FNB were between 17.8 %–26.9 % and 73.1 %–82.2 %. When the size cutoff was disregarded, an increase of correct recommendations and a decrease of incorrect recommendations was observed for all RSSs. Conclusion  The RSSs vary in their ability to correctly recommend for or against FNB. An understanding of the impact of nodule size cutoffs seems necessary for the future of TIRADS.

Purpose: To evaluate the impact of video sequences (cine-loops) on the interobserver agreement (IOA) using risk stratification systems (RSSs) for thyroid nodules (TNs). Methods: Twenty TNs were randomly selected from a large database and evaluated by twelve experienced observers using five different RSSs (Kwak-, ACR-, EU-, Korean-TIRADS, ATA Guidelines). In the first step, the evaluation was conducted based on static ultrasound (US) images in two planes (“static”). Six months later, these cases were reevaluated by the same observers using video sequences in two planes (“cine-loops”). Fleiss’ kappa (κ) was calculated for the IOA analyses. Results: IOA on static was moderate with κ values of 0.46, 0.42, 0.40, 0.45, and 0.38 for the Kwak-, ACR-, EU-, Korean-TIRADS, and ATA Guidelines, respectively, while the IOA on cine-loops was fair with κ values of 0.41, 0.38, 0.37, 0.36, and 0.34 for the Kwak-, ACR-, EU-, Korean-TIRADS, and ATA Guidelines, respectively. The overall IOA was superior in static images versus cine-loops (p = 0.024). Among other findings, the subgroup analyses (related to age, gender, US certificates, number of thyroid US per week, and RSSs experience) particularly showed that the experience of the observers in using RSSs had a significant influence on the IOA. Conclusions: The overall IOA (all twelve observers and all five RSSs) was superior on static US images in comparison to cine-loops. Furthermore, the overall IOA of the five US features revealed superior κ values of the static images over cine-loops. However, this impact was significantly lower when the observers were highly experienced in the use of US RSSs of TNs.

Purpose: (i) To examine the criterion taller-than-wide (TTW) for the sonographic assessment of thyroid nodules in areas of iodine deficiency in terms of frequency, anatomical distribution within the thyroid gland and risk of malignancy. (ii) To develop a model for nodule growth in the thyroid gland. Methods: German multicenter study consisting of two parts. In the prospective part, thyroid nodules were sonographically measured in all three dimensions, location within the thyroid gland and contact to a protrusion-like formation (horn) in the dorsal position of thyroid gland was noted. In addition, further sonographic features such as the composition, echogenity, margins and calcifications were investigated. All nodules from the prospective part were assessed for malignancy as part of clinical routine at the decision of the treating physician adhering to institutionally based algorithms. In the retrospective part, only nodules with fine needle aspiration and/or histology were included. The risk of malignancy in TTW nodules was determined by correlating them with cyotological and histological results. Results: Prospective part: out of 441 consecutively evaluated thyroid nodules, 6 were found to be malignant (1.4%, 95% CI 0.6–2.7%). Among the 74 TTW nodules (17%), 1 was malignant (1%, 95% CI 0–4%). TTW nodules were more often located in the dorsal half of the thyroid than non-TTW nodules (factor 2.3, p = 0.01, 95% CI 2.1–2.5) and more often located in close proximity to a horn than non-TTW nodules (factor 3.0, p = 0.01, 95% CI 2.4–3.8). Retrospective part: out of 1315 histologically and/or cytologically confirmed thyroid nodules, 163 TTW nodules were retrieved and retrospectively analyzed. A TTW nodule was 1.7 times more often benign when it was dorsal (95% CI 1.1–2.5) and 2.5 times more often benign when it was associated with a horn (95% CI 1.2–5.3). The overall probability of malignancy for TTW nodules was 38% (95% CI 30–46%) in this highly preselected patient group. Conclusion: TTW nodules are common in iodine deficient areas. They are often located in the dorsal half of the thyroid gland and are frequently associated with a dorsal protrusion-like formation (horn) of the thyroid. Obviously, the shape of benign nodules follows distinct anatomical preconditions within the thyroid gland. The frequency of TTW nodules and their predominant benignity can be explained by a pole concept of goiter growth. The difference between the low malignancy risk of TTW nodules found on a prospective basis and the high risk found retrospectively may be the result of a positive preselection in the latter.

Aim Thyroid scintigraphy enables the depiction of the functional status of thyroid nodules (TNs) with both, 99mTc-pertechnetate and 123Iodine. The functional status is relevant for diagnostic procedures for the differentiation of benign and malignant TNs. The aim of this study was to examine the current frequencies of hyper-, hypo- and isofunctioning TNs in Germany and to estimate the risk of malignancy with regard to functional status. Methods In 11 study centers, a minimum of 100 nodules per center were consecutively enrolled between July 2019 and April 2020. Inclusion criteria were: newly diagnosed nodule, nodule’ size of 10 mm or more, thyroid scintigraphy. Exclusion criteria were: completely cystic TNs, patients with prior radioiodine therapy or thyroid surgery. The risk of malignancy was estimated for hyper- and hypofunctioning TNs. Results Overall, 849 patients (72 % women) with 1262 TNs were included. Patients’ age ranged from 18 to 90 years. Most TNs were hypofunctioning (n=535, 42%) followed by isofunctioning TNs (n=488, 39%) and hyperfunctioning TNs (n=239, 19%). When only TNs with a maximum size of 2 cm or more were considered the rate of hyperfunctioning and hypofunctioning TNs increased (to 27% and 49%) while isofunctioning TNs decreased. Only one of all hyperfunctioning TNs was malignant. In hypofunctioning nodules, the malignancy rate was estimated at 10%. Conclusion In Germany, the proportion of hyperfunctioning TNs is approximately 20% and increases in larger TNs to up to 27%. Due to the low risk of malignancy in hyperfunctioning TNs, no further procedures to rule out malignancy are necessary. The risk of malignancy of hypofunctioning TNs is significantly higher. Thus, a thyroid scintigraphy is a useful diagnostic tool in Germany.

Ultrasonography and radionuclide imaging using [99mTc]Pertechnetate or radioactive iodine isotopes are essential tools used during the diagnostic workup of hyperthyroidism with or without structural alterations of the thyroid. Color duplex sonography and ultrasound elastography may add important information to find the cause of the hormone excess. During the last few years, hybrid imaging using SPECT/-(CT) or PET-based methods, such as [124]Iodine-PET/CT or [124]Iodine-PET/ultrasound have been increasingly used, playing a role in the context of localizing ectopic thyroid tissue or in multinodular goiter. Recently, promising data has been published on the use of [99mTc]MIBI imaging in amiodarone induced hyperthyroidism.

Germany has a long history of insufficient iodine supply and thyroid nodules occur in over 30% of the adult population, the vast majority of which are benign. Non-invasive diagnostics remain challenging, and ultrasound-based risk stratification systems are essential for selecting lesions requiring further clarification. However, no recommendation can yet be made about which system performs the best for iodine deficiency areas. In a German multicenter approach, 1211 thyroid nodules from 849 consecutive patients with cytological or histopathological results were enrolled. Scintigraphically hyperfunctioning lesions were excluded. Ultrasound features were prospectively recorded, and the resulting classifications according to five risk stratification systems were retrospectively determined. Observations determined 1022 benign and 189 malignant lesions. The diagnostic accuracies were 0.79, 0.78, 0.70, 0.82, and 0.79 for Kwak Thyroid Imaging Reporting and Data System (Kwak-TIRADS), American College of Radiology (ACR) TI-RADS, European Thyroid Association (EU)-TIRADS, Korean-TIRADS, and American Thyroid Association (ATA) Guidelines, respectively. Receiver Operating Curves revealed Areas under the Curve of 0.803, 0.795, 0.800, 0.805, and 0.801, respectively. According to the ATA Guidelines, 135 thyroid nodules (11.1%) could not be classified. Kwak-TIRADS, ACR TI-RADS, and Korean-TIRADS outperformed EU-TIRADS and ATA Guidelines and therefore can be primarily recommended for non-autonomously functioning lesions in areas with a history of iodine deficiency.

INTRODUCTION:Thyroid Imaging Reporting And Data System (TIRADS) is helpful for risk stratification of thyroid nodules. However, there is a lack of data for TIRADS classification of different histological subtypes [classical papillary thyroid cancer (PTC), follicular variant of papillary thyroid cancer (FVPTC), and follicular thyroid cancer (FTC)], and benign thyroid nodules (follicular adenoma, oncocytic adenoma, and multinodular goiter (MNG)]. Methoxy-isobutyl-isonitrile (MIBI) imaging has a high negative predictive value for the exclusion of thyroid malignancy in hypofunctioning thyroid nodules. The aim of this analysis was to compare malignant and benign subtypes of thyroid nodule using three TIRADS and MIBI imaging.METHODS:Retrospective analysis of MIBI imaging studies. Hypofunctioning thyroid nodules were classified with Kwak-TIRADS, EU-TIRADS, and K-TIRADS. MIBI imaging was visually categorized.RESULTS:We included 242 thyroid nodules (32 malignant, 19 PTC, 7 FVPTC, and 6 FTC). When using Kwak-TIRADS 4C and 5 as a marker for high-risk nodules, we found 85.5% of the follicular adenoma, 80.8% of the MNG, 100% of the oncocytic adenoma, 100% of the FTC, 57.1% of the FVPTC, and 42.2% of the PTC to be below this cutoff. All PTC and FVPTC were MIBI-positive, 83% of the FTC, 78% of the follicular adenoma, 75% of the oncocytic adenoma, and 60% of the MNG were MIBI-positive.CONCLUSION:TIRADS is useful to detect PTC, but FVPTC and FTC may be missed. MIBI imaging seems to be more suitable to detect FVPTC and FTC. However, neither TIRADS nor MIBI imaging are able to differentiate between follicular adenoma and FTC or FVPTC.

The Thyroid Imaging and Reporting System (TIRADS) allows a sonographic assessment of the malignancy risk of thyroid nodules (TNs). To date, there is a lack of systematic data about the change in ultrasound (US) features after therapeutic interventions. The aim of this study was to characterize the changes in autonomously functioning thyroid nodules (AFTNs) after radioiodine therapy (RIT) by using TIRADS. We retrospectively assessed data from 68 patients with AFTNs treated with RIT between 2016 and 2018 who had available first and second follow-up US imaging. Before RIT, 69.1% of the AFTNs were classified as low-risk TNs when applying Kwak TIRADS (EU-TIRADS 52.9%), 22.1% were intermediate-risk TNs (EU-TIRADS 19.1%), and 8.8% were high-risk TNs (EU-TIRADS 27.9%). Twelve months after RIT, 22.1% of the AFTNs showed features of high-risk TNs according to Kwak TIRADS (EU-TIRADS 45.6%). The proportion of intermediate TNs also increased to 36.8% (EU-TIRADS 29.4%), and 41.2% were low-risk TNs (EU-TIRADS 25%). A significant percentage of AFTNs presented with features suspicious for malignancy according to TIRADS before RIT, and this number increased significantly after therapy. Therefore, before thyroid US, thorough anamnesis regarding prior radioiodine treatment is necessary to prevent unneeded diagnostic procedures.

To investigate the interobserver agreement (IA) and the impact of consensus reading using four risk stratification systems for thyroid nodules (TN). Four experienced specialists independently rated US images of 80 TN according to the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines. The cases were randomly extracted from a prospectively acquired database (n > 1500 TN). The observers were blinded to clinical data. This study was divided into two sessions (S1 and S2) with 40 image sets each. After every session, a consensus reading was carried out (C1, C2). Subsequently, the effect of C1 was tested in S2 with 40 new cases followed by C2. Fleiss’ kappa (κ) was calculated for S1 and S2 to estimate the IA and learning curves. The results of C1 and C2 were used as reference for diagnostic accuracy calculations. IA significantly increased (p < 0.01) after C1 with κ values of 0.375 (0.615), 0.411 (0.596), 0.321 (0.569), and 0.410 (0.583) for the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines in S1 (S2), respectively. ROC analysis (C1 + C2) revealed similar areas under the curve (AUC) for the Kwak-TIRADS, EU-TIRADS, ACR TI-RADS, and ATA Guidelines (0.635, 0.675, 0.694, and 0.654, respectively, n.s.). AUC did not increase from C1 (0.677 ± 0.010) to C2 (0.632 ± 0.052, n.s.). ATA Guidelines were not applicable in five cases. IA and diagnostic accuracy were very similar for the four investigated risk stratification systems. Consensus reading sessions significantly improved the IA but did not affect the diagnostic accuracy.

Due to the widespread use of ultrasound, small thyroid nodules (TNs) ≤ 10 mm are common findings. Standardized approaches for the risk stratification of TNs with Thyroid Imaging Reporting and Data Systems (TIRADS) were evaluated for the clinical routine. With TIRADS, the risk of malignancy in TNs is calculated by scoring the number or combination of suspicious ultrasound features, leading to recommendations for further diagnostic steps. However, there are only scarce data on the performance of TIRADS for small TNs. The aim was to compare three different TIRADS for risk stratification of small TNs in routine clinical practice. We conducted a retrospective cohort analysis of TNs ≤ 10 mm and their available histology. Nodules were classified according to three different TIRADS. In the study, 140 patients (n = 113 female) with 145 thyroid nodules (n = 76 malignant) were included. Most of the malignant nodules were papillary carcinoma (97%), and the remaining 3% were medullary carcinoma. For all tested TIRADS, the prevalence of malignancy rose with increasing category levels. The highest negative predictive value was found for ACR TI-RADS and the highest positive predictive value for Kwak-TIRADS. All tested variants of TIRADS showed comparable diagnostic performance for the risk stratification of small TNs. TIRADS seems to be a promising tool to reliably assess the risk of malignancy of small TNs.

AbstractFor the assessment of hyperparathyroidism besides cervical ultrasound, 99 mTc-Sestamibi (MIBI) imaging is being used on a routine basis in nuclear medicine practice. MIBI is a positively charged complex, which is bound in mitochondria rich parathyroidal tissue and shows a reduced washout as compared to normal thyroid tissue. This characteristic is used during dual-phase imaging by acquiring early and late images.In order to better localize adenomas, especially if they are ectopic, it is helpful to combine planar imaging with cross-sectional (-hybrid) imaging using SPECT or SPECT/CT. With this approach, in combination with ultrasound the sensitivity for adenomas is known to be over 80 % up to 100 %. For multiglandular involvement or hyperplasia, a significantly lower detection rate is known, which, however, can be improved by a combination of planar and tomografic imaging. To what extend medication can influence the results of MIBI imaging is not well known. Glucocorticoids and calcium channel antagonist might have a negative influence on the uptake of MIBI. Another potential influencing factor could be the presence of P-glykoprotein in some adenomas, leading to a faster efflux of MIBI out of the adenoma cells and consecutively a lower detection rate.

Introduction Thyroid scintigraphy with(99m)Tc-methoxyisobutylisonitrile (MIBI) is a helpful tool for the risk stratification of thyroid nodules (TN). Whereas a nodule with low or hypointense MIBI uptake has a low risk for malignancy, a hyperintense uptake may indicate a malignant nodule, which requires surgical resection. The appropriate diagnostic or therapeutic regimen of an isointense nodule with an uptake similar to the paranodular tissue is discussed controversially. Aim of this study was to assess the interobserver agreement (IA) for the assignment of TN to the three categories: hypo-, iso-or hyperintense. Methods Retrospective analysis of planar and SPECT images of MIBI scintigraphy was performed in 36 randomly selected patients with hypofunctioning TN and histological diagnosis. Four observers with different levels of experience in MIBI-scintigraphy analyzed MIBI uptake and assigned the nodules to the appropriate category. To assess the IA, Fleiss' Kappa was calculated. Results The study cohort included 11 patients with papillary thyroid carcinoma (diameter 20.3 mm) and 25 patients with benign nodules (diameter 24.8 mm). The IA for all nodules using planar images was 0.76 compared to 0.80 for SPECT images. The IA was better in the subgroup of malignant nodules for planar images as well as SPECT images (Kappa 0.91 and 0.90, respectively) compared to benign nodules (0.65 and 0.76, respectively). Using SPECT images, only one thyroid carcinoma presented with hypointense uptake, the remainder with hyper- or isointense uptake. In contrast, benign nodules were found in all categories. Conclusion MIBI scintigraphy shows a good IA for the interpretation of thyroid carcinoma. The IA is further improved if MIBI scintigraphy is performed in SPECT technique.

Thyroid nodules are a common finding, especially in iodine-deficient regions. Ultrasonographic scoring systems such as the Thyroid Imaging Reporting and Data System (TIRADS) are helpful in differentiating between benign and malignant thyroid nodules by offering a risk stratification model. Depending on the constellation or number of suspicious ultrasound features, a fine-needle biopsy is recommended. However, none of the previous TIRADS publications considered the functional status of the nodules. Hyperfunctioning thyroid nodules (HTNs) were presumed to exclude malignancy with a very high negative predictive value. Particularly in regions where the iodine supply is low, most HTNs are seen in patients with normal thyroid-stimulating hormone levels. Therefore, thyroid scintigraphy is essential for the detection of HTNs. We investigated whether TIRADS identifies HTNs as nonsuspicious. Methods: We evaluated 615 HTNs (23.2 ± 10.0 mm in maximum diameter in 582 patients ([442 women, 57.7 ± 13.2 y old, and 140 men, 60.1 ± 12.7 y old) detected by 99mTc-pertechnetate or 123I scintigraphy. Before evaluating the scintigraphic appearance, all nodules were analyzed prospectively with sonography, using the TIRADS model referenced in Kwak et al., wherein fine-needle biopsy is recommended for TIRADS 4A or higher. We also investigated 2 subgroups, 42 nodules with available histology and 117 patients with subclinical or overt hyperthyroidism. Results: Whereas 15.9% of the nodules were classified as TIRADS 3 or lower and less than 0.1% as TIRADS 5, most of the nodules were classified as TIRADS 4A (29.3%), 4B (29.3%), or 4C (24.9%). Altogether, more than 80% of the autonomous thyroid nodules were classified as TIRADS 4A or higher, a grade that would result in a recommendation of fine-needle biopsy. Focusing on those 117 HTNs that were already associated with hyperthyroid laboratory values, the rates were similar: 81.2% were categorized as TIRADS 4A or higher (4A, 33.3%; 4B, 29.9%; 4C,17.1%; 5, 0.9%). In the subgroup of patients who underwent thyroid surgery, all nodules were benign, confirming the known negative predictive value of HTNs with regard to malignancy exclusion. Conclusion: Integration of thyroid scintigraphy into the TIRADS model is essential to prevent unnecessary fine-needle biopsy and thyroid surgery.

To evaluate the diagnostic performance of elastography alone and combined with Thyroid Imaging Reporting And Data System (TIRADS) for the assessment of non-autonomous thyroid nodules. We included 244 thyroid nodules and analyzed the visual elasticity scores, strain value (SV) and TIRADS classification. Histologic examination revealed 38 malignant (16%) and 206 benign nodules. The SV was lower in malignant nodules than in benign with an optimal cutoff ≤0.225. The visual elasticity scores showed a better diagnostic performance than the SV measurement. The risk for malignancy increased with higher TIRADS category. The sensitivity, specificity, positive predictive value and negative predictive value of TIRADS were superior to sonoelastography. The combination of TIRADS ≥4C and SV ≤0.225 showed the highest odds ratio to predict malignancy. Kwak-TIRADS classification is superior to elastography for the differentiation of benign and malignant thyroid nodules. Our data demonstrate that a high TIRADS class alone is predictive for thyroid carcinoma and the clinical relevance of sonoelastography is negligible.

Die nuklearmedizinische Labordiagnostik war in der Vergangenheit integraler Bestandteil einer jeden nuklearmedizinischen Institution, sowohl in universitären Einrichtungen, nuklearmedizinischen Krankenhausabteilungen als auch in nuklearmedizinischen Praxen. Durch die zunehmende Verbreitung nicht-radioaktiver immunologischer Analyseverfahren, aber auch wirtschaftliche Faktoren, ist in den letzten Jahren sowohl ein Rückgang des Parameterspektrums als auch eine Abnahme der Institutionen, die ein eigenes nuklearmedizinisches Labor betreiben, zu beobachten – v. a. im universitären und stationären Bereich. Eine aktuelle Umfrage der Deutschen Gesellschaft für Nuklearmedizin ergab, dass nur noch in etwas mehr als einem Drittel der universitären nuklearmedizinischen Einrichtungen ein eigenes Labor betrieben wird, während im niedergelassenen Bereich noch mehr als die Hälfte der nuklearmedizinischen Praxen ein eigenes Labor vorhalten.

Thyreoglobulin ist das vorherrschende Protein der Schilddrüse und essenzieller Bestandteil der Schilddrüsenhormonsynthese. Während mit unempfindlichen historischen Bestimmungsmethoden Thyreoglobulin nur selten im Serum von Patienten nachgewiesen werden konnte, erlauben aktuelle, hochsensitive Bestimmungsmethoden den Nachweis schon geringster Thyreoglobulinkonzentrationen im Serum. Diese Übersicht gibt einen Überblick über die Entwicklung der aktuellen Bestimmungsmethoden und deren Limitationen. Zudem wird neben der etablierten klinischen Anwendung in der Nachsorge des differenzierten, nicht-medullären Schilddrüsenkarzinoms die Rolle des Thyreoglobulins bei der Einschätzung von Schilddrüsenknoten, der Abklärung einer ätiologisch unklaren Hyperthyreose, der kongenitalen Hypothyreose, als Monitoring-Parameter von Krankheitsbildern mit erhöhter Schilddrüsenfollikeldestruktion und als Biomarker der Iodversorgung betrachtet.

Zur Dignitatsabklarung hypofunktioneller Schilddrusenknoten kann eine Szintigraphie mit 99mTc-MIBI erfolgen. Bei Minderspeicherung im Pertechnetat- und MIBI-Szintigramm lasst sich ein Schilddrusenkarzinom relativ sicher ausschliesen. Bei vermehrter MIBI-Anreicherung wird eine Operation empfohlen. Die Einstufung isointenser Knoten wird kontrovers gesehen. Untersucht wurde, welche Karzinompravalenz isointense Knoten zeigen und ob sich durch SPECT-Technik ein diagnostischer Zugewinn ergibt. Patienten, Methodik: Retrospektive Auswertung von MIBI-Szintigraphien in planarer und SPECT-Technik. Die Szintigraphie erfolgte nach Applikation von 510 MBq 99mTc-MIBI eine Stunde p. i. Die Auswertung erfolgte visuell mit Einteilung der Knoten in hypo-, iso- und hyperintens im Vergleich zum paranodularen Gewebe. Ergebnisse: Bei 83 von 225 Patienten mit MIBI-Szintigraphien erfolgte eine histologische Sicherung (Alter 48,6 ± 12,6 Jahre, 72% weiblich). Es fanden sich 12 papillare Karzinome (14,5%). Bei planarer Aufnahme wurden 12, 34 bzw. 37 Knoten, in den SPECT-Aufnahmen 16, 21 bzw. 46 Knoten als hypo-, iso- bzw. hyperintens eingestuft. Unter den in planarer Technik als hypo-, iso- bzw. hyperintens eingestuften Knoten fanden sich 1, 5 bzw. 6 Karzinome und bei tomographischer Technik kein, 4 bzw. 8 Karzinome. Wurden die iso- und hyperintensen Knoten als malignomsupekt zusammengefasst, ergaben sich fur Sensitivitat, Spezifitat, NPV und PPV bei planarer Aufnahme Werte von 91,7, 15,5, 91,7 bzw. 15,6% und bei tomographischer Aufnahme 100, 22,5, 100 bzw. 17,9%. Schlussfolgerung: Hypofunktionelle SD-Knoten mit iso- und hyperintenser MIBI-Speicherung zeigen eine vergleichbare Malignompravalenz. Durch die Untersuchung in SPECT-Technik ergibt sich eine Verbesserung insbesondere von Sensitivitat und negativem Vorhersagewert.

Summary Background: Subacute thyroiditis is a usually self-limiting disease of the thyroid. However, approximately 0.5–15% of the patients require permanent thyroxine substitution. Aim was to determine predictive factors for the necessity of long-term hormone-replacement (LTH). Patients, methods: We retrospectively reviewed the records of 72 patients with subacute thyroiditis. Morphological and serological parameters as well as type of therapy were tested as predictive factors of consecutive hypothyroidism. Results: Mean age was 49 ± 11 years, f/m-ratio was 4.5 : 1. Thyroid pain and signs of hyperthyroidism were leading symptoms. Initial subclinical or overt hyperthyroidism was found in 20% and 37%, respectively. Within six months after onset 15% and 1.3% of the patients developed subclinical or overt hypothyroidism, respectively. At latest follow-up 26% were classified as liable to LTH. At onset the thyroid was enlarged in 64%, and at latest follow-up in 8.3%, with a significant reduction of the thyroid volume after three months. At the endpoint the thyroid volume was less in patients in the LTH group compared with the non-LTH group (41.7% vs. 57.2% of sex-adjusted upper norm, p = 0.041). Characteristic ultrasonographic features occurred in 74% of the patients in both lobes. Serological and morphological parameters as well as type of therapy were not related with the need of LTH. Conclusions: In this study the proportion of patients who received LTH was 26%. At the endpoint these patients had a lower thyroid volume compared with euthyroid patients. No predictive factors for LTH were found.

The cytological diagnosis of follicular neoplasm is a common finding in fine needle aspiration cytology (FNAC) of thyroid nodules and includes benign disease as well as differentiated thyroid cancer. The aim of the study is to determine if thyrotropin is a predictive factor for a malignant nature of follicular neoplasm. Patients, methods: The records of 119 patients with follicular neoplasm on FNAC, who underwent surgery for final diagnosis, were reviewed retrospectively. The predictive value of serum parameters including thyrotropin, thyroglobulin, and anti-thyroid antibodies, ultrasonographic criteria and clinical variables was evaluated by univariate analysis and logistic regression analysis. Results, discussion: Patients with malignant nodules showed a higher thyrotropin concentration compared to patients with benign nodules (median 1.6 mU/l, interquartile range 1.4–3.0 mU/l vs. median 1.2 mU/l, interquartile range 0.8–1.6 mU/l, p < 0.01). ROC-analysis of thyrotropin revealed an optimal cut off value to differentiate benign and malignant nodules of 1.34 mU/l. The incidence of malignancy was 30.3% for a thyrotropin concentration higher than 1.34 mU/l compared to 6.4% for a thyrotropin concentration lower than or equal to 1.34 mU/l. On univariate analysis thyroglobulin higher than 300 ng/ml, positive anti-thyroid antibodies, hypoechogenicity, and ill-defined margins, respectively, were also significantly associated with malignancy. On logistic regression analysis higher thyrotropin concentrations, ill-defined margins, and thyroglobulin higher than 300 ng/ml, respectively, were independent predictive factors for malignancy (OR 20.0, 10.7, and 22.7, respectively). Conclusion: Higher thyrotropin concentrations are predictive for a malignant nature of follicular neoplasm.