Background: The early diagnosis of medullary thyroid carcinoma (MTC) is crucial for effective therapy. Elevated plasma calcitonin concentrations (pCT-Cs) are generally a specific and sensitive indicator for C-cell hyperplasia or MTC. The presence of thyroid nodules raises the possibility of MTC. Hence, in endemic goiter regions, there is a need for information regarding the pCT-C values that are indicative of C-cell hyperplasia or MTC. The aim of this study, therefore, was to determine an upper pCT-C to distinguish patients with and without MTC in a collective with nodular thyroid disease, and to give an estimation of the prevalence of MTC in an endemic goiter area. Methods: Basal pCT-C was measured in 21,928 patients with thyroid nodules living in central Germany, an area with endemic goiter due to previous iodine deficiency. In 218 subjects with pCT-Cs exceeding 10 ng/L, stimulated pCT-C was additionally determined, as suggested by the German consensus recommendation. A nominal normal range for basal pCT-C was calculated with data from 21,900 subjects without known MTC. The predicted upper limit was then validated using the known diagnoses of 376 patients with pCT-Cs exceeding 10 ng/L, 28 of whom presented with MTC. Results: For basal pCT-C, calculation of the three-sigma borders after logarithmic transformation revealed upper limits of the nominal normal range of 14.6 ng/L in females and 32.8 ng/L in males, respectively. However, three male patients with small MTCs had basal pCT-Cs between 15 and 33 ng/L. None of the patients with MTC had a basal pCT-C below 15 ng/L or an increase in pCT-C after pentagastrin stimulation that was less than 80 ng/L. In the basal pCT-C range between 15 and 50 ng/L (n = 192; eight with MTC), the positive predictive value for the detection of MTC was 4% in our group. Applying an upper limit for basal pCT-C of 15 ng/L in both sexes, 329 of the total of 21,928 patients exceeded this range. Among these, the final outcome is known in 231 subjects, including all 28 MTCs. Conclusions: An upper limit of 15 ng/L instead of 10 ng/L for basal pCT-C is able to detect all MTC and reduce false-positive cases. The prevalence of MTC in nodular thyroid disease in our group was approximately 1.8 per thousand.

Purpose The purpose of this study was to aid in the standardization of lymphoscintigraphy for detecting the sentinel node (SN) in breast cancer using Tc-99m–labeled nanocolloidal albumin. Materials and Methods One hundred twenty-three women with proved breast cancer were enrolled. Four injections of 10 to 15 MBq (0.27 to 0.41 mCi) Tc-99m nanocolloid in 0.1 ml physiologic saline were administered intra- and subdermally at the margin of the skin overlying the tumor. Planar scintigraphic images in the lateral and anterior projections were obtained 2.5 to 18 hours after tracer administration. With a gamma probe used as a guide, all radioactive lymph nodes in the axilla were resected. Complete dissection then followed. Results In 116 of the 123 (94%) women, axillary nodal tracer uptake was revealed. Six of the 7 women in whom detection failure occurred had histologically proved tumor infiltration of the lymphatics and axillary involvement. In 36 (31%) of the patients with visualized lymph nodes, the SN was metastatic. The remaining 80 patients with negative SN included three cases with axillary involvement. The sensitivity of the SN with respect to the histologic status of the entire axilla thus was 92.3%, and the negative predictive value was 96.3%. The overall accuracy of the method was 97.4%. The number of hot nodes in women with and without axillary involvement was significantly different. Conclusions The described protocol represents an easily reproduced and reliable method for SN detection in breast cancer. Furthermore, the number of visualized axillary nodes reflects the histologic status of the axilla.

Aim of this study was to evaluate the results of o standardized protocol for sentinel node (SN) detection in breast cancer using Tc-99m labeled nanocolloidal albumin and a combined intra- and subdermal injection technique. Methods: One hundred and fifty-five women with proven breast cancer (disease stages Tis-T2) were included. Four injections of 10 to 15 MBq of Tc-99m nanocolloid in 0.1 ml physiologic saline were administered intra- and subdermally at the 3,6,9 and 12 o’clock positions in the skin overlying the tumor. Planar scintigraphic images in lateral and anterior projections were obtained once between 2.5 and 18 hours after tracer administration. Guided by a gamma probe, all radioactive lymph nodes in the axilla were resected, then complete dissection followed. Results: In 151 of the 155 women (97.4%), nodal tracer uptake (range 1-7 foci, average 2.2) was scinligraphically revealed. In one of these cases, drainage was only to the internal mammary lymphatic chain. Three of the 4 women with detection failure presented with histologically proven tumor infiltration of the lymphatics and axillary involvement. In 49 of the patients with visualized axillary lymph nodes (32.7%), at least one SN was metastatic. In 21 cases, this SN was the only positive node. The remaining 101 patients with negative SN included 4 cases with axillary involvement. The sensitivity of the SN with respect to the histological status of the entire axilla was thus 92.5%, the negative predictive value was 96.0%. The overall accuracy of the method was 97.3%. There was a significant difference between the number of totally detected radioactive nodes in the groups with and without nodal metastases (3.49 vs. 2.57, p <0.01). Conclusion: The described protocol represents an easy reproducible and reliable method for SN detection in breast cancer that additionally allows flexible timing of surgery. Further, we found evidence that the number of scinligraphically visualized nodes also reflects the histological status of the axilla. Ziel dieser Studie war die Evaluierung der Ergebnisse eines standardisierten Protokolls zur Darstellung des Sentinel Node (SN) bei Mammakarzinomen unter Verwendung einer kombinierten intra- und subkutanen Injektionstechnik. Methoden: Insgesamt wurden 155 Patientinnen mit Mammakarzinom im Stadium Tis-T2 untersucht. Vier Injektionen mit jeweils 10-15 MBq Tc-99m-markiertem Nanocoll wurden intra- und subkutan in den Rondbereich der Haut über dem Tumor appliziert. Planare Szintigramme in lateraler und ventraler Sicht erfolgten zwischen 2,5 und 18 Stunden p. i. Nach genauer Lokalisation mit einer Gammasonde wurden intraoperativ zunächst alle radioaktiven Lymphknoten reseziert, danach folgte die komplette Axilladissektion. Ergebnisse: In 151 der 155 Fälle (97,4%) stellten sich szintigraphisch jeweils ein oder mehrere SN dar (insgesamt zwischen 1 und 7 LK, Mittelwert 2,2). In einem dieser Fälle erfolgte der Abfluss ausschließlich in die parasternale Lymphknotengruppe. Bei 3 der 4 Patientinnen ohne detektierbaren Lyrnphabfluss fand sich histologisch eine Tumorinfiltration der Lymphbahnen mit axillärer Metastasierung. Bei 49 der Frauen mit axillärem Lyrnphabfluss (32,7%) zeigte sich histologisch zumindest ein positiver SN. In 21 Fällen war dies der einzige befallene LK. Von den übrigen 101 Patientinnen mit negativen SN fand sich in 4 Fällen eine axilläre Metastasierung. Die Sensitivität des SN zur Vorhersage des Nodalstatus errechnet sich somit zu 92,5%, der negative prädiktive Wert zu 96,0% und die Genauigkeit zu 97,3%. Darüber hinaus zeigte sich ein signifikanter Unterschied zwischen der Zahl der insgesamt detektierten radioaktiven LK in der Gruppe mit bzw. ohne axilläre Metastasierung (3,49 vs. 2,57, p <0,01). Schlussfolgerung: Das beschriebene Protokoll stellt eine leicht reproduzierbare und zuverlässige Methode zur SN-Detektion dar. Ferner konnte gezeigt werden, daß die Anzahl der szintigraphisch nachweisbaren Lymphknoten auch Hinweise auf den Nodalstatus gibt.

AIM of this study is the introduction and validation of a simple model of the intrathyroidal iodine kinetics, designed for optimizing radioiodine therapy planning and dose measurement in a routine clinical setting. The new model defines the intrathyroidal iodine kinetics as balance of the thyroidal iodine intake and -excretion, characterized by the two exponential equations A(t) = A(0) * (1-exp(-lambda(1) t)) and A(t) = A(0) * (exp(-lambda(2) t) -1), respectively. A(0) describes the theoretically maximum iodine uptake when the thyroidal iodine excretion is ignored, lambda(1) and lambda(2) represent the constants characterizing the iodine intake and excretion, respectively. The thyroidal iodine content at the time t equals the sum of both functions, which is A(t) = A(0) * (exp(-lambda(2) t)-exp(-lambda(1) t)). In 25 patients with autonomous goiter / nodules (n = 18), Graves' disease (n = 5), or endemic euthyroid goiter (n = 2), the iodine uptake in the thyroid during the radioiodine therapy as fraction of the applied activity was determined daily, with the remaining body covered by a lead shield. On average, 7.2 measurements were performed per patient (minimum 4, maximum 13). With these uptake values, individual regression curves were fitted using the above equation, and the difference between the actual measurements and the corresponding values of the regression curves was determined. The average deviation of the 179 uptake values from the calculated points of the respective regression curves was only 1.4%. There was no significant difference between the three disease groups. The distribution of the relative deviations during the individual courses was constant, systematic errors were not detected. Our results suggest that the intrathyroidal iodine kinetics can be precisely described with the model A(t) = A(0) * (exp(-lambda(2) t)-exp(-lambda(1) t)). With only three measurements, the trend of the curve can be calculated, which allows to determine the total radioiodine storage in the thyroid.

Aim of this study is the validation of a simple method for evaluating the depth of the target volume within the radioiodine test by analyzing the emitted iodine-131 energy spectrum. Patients, methods: In a total of 250 patients (102 with a solitary autonomous nodule, 66 with multifocal autonomy, 29 with disseminated autonomy, 46 with Graves’ disease, 6 for reducing goiter volume and 1 with only partly resectable papillary thyroid carcinoma), simultaneous uptake measurements in the Compton scatter (210 ±110 keV) and photopeak (364–45/+55 keV) windows were performed over one minute 24 hours after application of the 3 MBq test dose, with subsequent calculation of the respective count ratios. Measurements with a water-filled plastic neck phantom were carried out to perceive the relationship between these quotients and the average source depth and to get a calibration curve for calculating the depth of the target volume in the 250 patients for comparison with the sonographic reference data. Another calibration curve was obtained by evaluating the results of 125 randomly selected patient measurements to calculate the source depth in the other half of the group. Results: The phantom measurements revealed a highly significant correlation (r = 0,99) between the count ratios and the source depth. Using these calibration data, a good relationship (r = 0,81, average deviation 6 mm corresponding to 22%) between the spectrometric and the sonographic depths was obtained. When using the calibration curve resulting from the 125 patient measurements, the average deviation in the other half of the group was only 3 mm (12%). There was no difference between the disease groups. Conclusion: The described method allows an easy to use depth correction of the uptake measurements providing good results. Ziel dieser Arbeit ist die Validierung einer einfachen Methode zur Ermittlung der Tiefe des Zielvolumens aus dem emittierten Spektrum des Iod-131 im Rahmen des Radioiodtests. Patienten, Methoden: Bei 250 Patienten (168 mit (multi) fokaler bzw. 29 mit disseminierter Autonomie, 46 mit M. Basedow, 6 zur Strumaverkleinerung sowie 1 mit nur teilresektablem papillären Karzinom) erfolgten simultane, einminütige Uptake-Messungen im Comptonfenster (210 ± 110 keV) und im Photopeak (364–45/+55 keV) 24 Stunden nach Applikation von 3 MBq Iod-131 mit Errechnung des Quotienten beider Zählraten. Durch Phantommessungen wurde die Beziehung zwischen diesem Verhältnis und der mittleren Tiefe der Quelle einschließlich einer Regressionsgleichung bestimmt, aus der die Tiefe des Zielvolumens der Patienten ermittelt und mit den sonographischen Referenzwerten verglichen wurde. Eine weitere Eichkurve wurde aus den Ergebnissen von 125 zufällig selektierten Patientenmessungen erstellt und damit die Tiefe des Zielvolumens der zweiten Hälfte des Kollektivs errechnet. Ergebnisse: Die Phantommessungen ergaben eine hochsignifikante Abhängigkeit (r = 0,99) zwischen dem Streuverhältnis und der Tiefe der Quelle. Unter Verwendung dieser Daten als Referenz zeigte sich im gesamten Patientenkollektiv eine gute Korrelation zwischen der spektrometrisch und der sonographisch ermittelten Gewebetiefe (r = 0,81, mittlere Abweichung 6 mm, entsprechend 22%). Bei Verwendung der Eichkurve aus den 125 Patientenmessungen ergab sich für die anderen 125 Fälle eine mittlere Abweichung von nur noch 3 mm (12%). Unterschiede zwischen den einzelnen Krankheitsgruppen fanden sich nicht. Schlussfolgerungen: Die dargestellte Methode ermöglicht mit hinreichender Genauigkeit und geringem Aufwand eine Tiefenkorrektur der Uptake-Messungen.