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Aim: Zirconium-89 has gained great interest for PET, when imaging at late time points is required. Desferrioxamine B (DFO), is mostly used for this radionuclide as bifunctional chelator (BFC) and w ...

SummaryGaucher disease is the most prevalent inherited, lysosomal storage disease and is caused by deficient activity of the enzyme β-glucocerebrosidase. Bone and bone marrow alterations are frequent in the most prevalent non-neuronopathic form of Gaucher disease. Imaging of bone manifestations in Gaucher disease is performed by a variety of imaging methods, conventional X-ray and MRI as the most frequently and most important ones. However, different modalities of scintigraphic imaging have also been used. This article gives an overview on scintigraphic imaging with respect to bone manifestations in Gaucher disease discussing the advantages and limitations of scintigraphic imaging in comparison to other imaging methods.

Summary Due to the introduction of new lipophilic radiotracers like Tc-99m Sestamibi or Tc-99m Tetrofosmin in conventional scintigraphy and the implementation of FDG-PET in clinical routine in the last decade, their role in primary staging, restaging and therapy monitoring in breast cancer patients has been extensively evaluated. Concerning primary diagnosis, both scintimammography (SMG) and FDG-PET cannot be recommended for small nodules

The aim of our study was a direct comparison of the ability of positron-emission tomograpy with FDG-PET and of magnetic resonance imaging (MRI) to determine whether breast lesions were benign or malignant and of the two imaging methods capability of depicting eventual multifocal disease. We performed both PET and MRI in 36 patients (40 lesions) who were scheduled for surgery because of suggestive mammographic, sonographic and/or clinical findings. A final histological classification was available for all lesions. Tumour size ranged from 5 to 45 mm (mean 16.7 mm). Sensitivity for lesions, sensitivity for patients, specificity for lesions and specificity for patients were 68.0%, 76.2%, 73.3%, and 73.3% for PET and 92.0%, 95.2%, 73.3%, and 73.3% for MRI, respectively. MRI was more sensitive than FDG-PET in disclosing malignant breast tumours and was also more accurate than FDG-PET in the assessment of multifocal disease. The lower sensitivity of FDG-PET than of MRI seems to be due to difficulties in reliable imaging of carcinomas smaller than 10 mm and of lobular carcinomas.

Background: Sentinel lymph node detection with radiocolloids is confronted with the same problem as the blue dye (BL) method: Even now there is no standardized procedure as regards the application method, the amount of radioactivity and injected volume of the radiocolloid (RC). Therefore, our aim was to find out the most reliable application method and to evaluate a possible tumour-site dependence of detectability.

A variety of indications for radiosynoviorthesis have been reported in literature, but the clinical outcome differs and depends on the primary disease and the pre-existing degenerative changes. This metaanalysis was carried out to establish groups for radiosynoviorthesis based on clinical outcome with respect to primary disease, clinical stage and the pre-existing degenerative changes. The literature search was carried out using the MEDLINE search term 'radionuclide synovectomy'. Based on reports in the literature we determined groups for radiosynoviorthesis for clinical use. Our literature list comprised 2190 joints that were treated with radiosynoviorthesis. The overall response rate for all treated joints was 72.5+/-17%. The mean improvement rate for the treated joints in rheumatoid arthritis was 66.7+/-15.4%. For osteoarthritis the success rate was 56+/-11%, with better results in case of minimal radiological changes. Radiosynoviorthesis in patients with changes according to Steinbrocker I and II was successful in 72.8+/-12.3%, and in 64+/-17.3%, respectively. Steinbrocker III and IV had a mean success rate of 52.4+/-23.6%. In the case of haemophilia and Willebrand's disease a reduction of joint bleedings and factor usages after radiosynoviorthesis was evident in 91+/-4.3%. In patients with pigmented villonodular synovitis radiosynoviorthesis was successful in 77.3+/-25.3%. It is concluded that radiosynoviorthesis provides better results in rheumatoid arthritis than in osteoarthritis. Minimal or moderate changes according to Steinbrocker stages I and II respond better to radionuclide therapy than do stages III and IV. Deformed or unstable joints might fail treatment and therefore surgical interventions should be considered. Close cooperation with orthopaedists and rheumatologists is necessary to consider radiosynoviorthesis in each patient to ensure optimal medical care.

Summary Aim: Retrospective evaluation of Tc-99m ciprofloxacin (infecton) scintigraphy consecutively performed in a series of patients clinically suspected for peripheral osteomyelitis (OM), spondylodiscitis (SD) and fever of unknown origin (FUO). Methods: A total of 20 patients clinically suspected for OM (n = 12), SD (n = 3) and FUO (n = 5) were included in our retrospective analysis. The additional criterion was a positive 3-phase bone scan for OM, or a 2-phase bone scan in case of SD. Planar whole body scans and static acquisitions were performed 1 and 4 h after application of 370 MBq Tc-99m ciprofloxacin. In 10 patients with suspected OM, additional immunoscintigraphy using Tc-99m labelled monoclonal antibodies (Mab BW 250/183) was performed and the correlation of infecton to bloodpool and antigranulocyte scintigraphy was analysed. Results: OM: Bacterial infection was confirmed in 8 of 15 lesions. Infecton demonstrated true positive (TP) results in 7 of 8, true negative (TN) results in 2 of 7, false positive (FP) results in 5 of 7 patients and one false negative (FN) result. A strong correlation could be demonstrated between T/NT ratios of infecton and bloodpool Tc-99m medronate imaging (r = 0.84, 0.88) and between infecton and BW 250/183 (r = 0.92, 0.90). Using a threshold of 2.0 for T/NT ratio, only TP results could be observed whereas a T/NT in the range of 1.0-2.0 could not discriminate between septic and aseptic inflammation. Concordant results with Mab BW 250/183 could only be observed in 5 of 10 patients (4 TP, 1 TN) by showing 4 FP and 1 FN lesions with IF. Conclusion: Non-specific uptake of infecton can be observed in a variety of clinical situations with moderate uptake, by showing a strong correlation with blood-pool imaging. Nevertheless, intense uptake may be specific for septic inflammation.

Summary Aim: The goal of this study was to assess the accuracy and limitations of ultrasound guided fine-needle aspiration biopsy (ug-FNAB) of solitary thyroid nodules. Methods: The ug-FNAB results of 538 patients with solitary thyroid nodules, who afterwards underwent thyroid surgery, were compared retrospectively with the histology. Patients with multinodular goiter were excluded from the study. Ug-FNAB was performed on growing and/or hypoechoic and/or hypofunctional nodules. The ug-FNAB results were grouped as follows: group 1: malignant (n = 44); group 2: malignancy cannot be ruled out (n = 173); group 3: non-malignant (n = 296), group 4: inadequate (n = 25). Results: When the cytological results of group 1 and group 2 were interpreted os being malignant and those of group 3 as being benign, sensitivity, specificity and accuracy of ug-FNAB were 96.7%, 65.8% and 69.5% respectively. The 62 thyroid carcinomas (TO biopsied presented in 59 cases a suspicious or malignant cytology (95.2%). The smallest TC diagnosed by ug-FNAB had a diameter of 0.5cm and 36.4% of all papillary TC ≤ 1 cm displayed stage pT4. The histology verified a TC in 18 cases out of the 173 ug-FNABs in group 2. Non-malignant ug-FNABs were confirmed by histology in 294 patients (99.3%) in group 3. In 4.65% of the ug-FNABs inadequate material was aspirated. Conclusion: Nodules with non-suspicious ug-FNAB results can be safely followed-up by sonography, as the cytological diagnoses were verified in more than 99% by histology. Papillary TC can be diagnosed with ug-FNAB very accurately. As stage pT4 was present in more than one third of patients with papillary TC ≤ T cm, ug-FNAB is also recommended for thyroid nodules 0.5-1 cm in diameter located adjacent to the thyroid capsule. However, microfollicular proliferations remain the limitation of ug-FNAB, as the cytology cannot distinguish between benign adenoma and follicular TC.

ZusammenfassungEine 73jährige Patientin zeigte bei der 99mTc-Schilddrüsenszintigraphie eine von der Schilddrüse abgesetzte deutliche fokale Speicherung links kaudal der Schilddrüse. Die weitere diagnostische Abklärung mittels Sonographie, CT, Ösophagoskopie und videoassistiertem Kontrastmittelschluckakt ergab als Ursache der 99mTc-Speicherung eine Achalasie. Die Erklärung einer 99mTc-Speicherung in der Speiseröhre wäre die unspezifische 99mTc-Aufnahme in den Speicheldrüsen mit nachfolgender Tracerelimination über den Speichel. Depotbildungen von Speichel bei Erkrankungen der Speiseröhre, die mit einer Transportstörung des Speichels verbunden sind, können dadurch Schilddrüsengewebe vortäuschen.

Summary Aim: The aim of our study was to evaluate the possibility of intraoperative scintimetric detection of parathyroid adenomas with Tc-99m labelled tracers for its usefulness in dystopic or ectopic adenomas. Methods: 12 women with biochemically confirmed hyperparathyroidism were included in our study. After injection of 370 MBq Tc-99m tetrofosmin e.g. sestamibi, preoperative scintigraphy (double phase study and SPECT) was performed and T/NT ratios were evaluated for early, delayed and SPECT images. Surgery was performed using a handheld gamma-probe after preoperative injection of 555-925 MBq Tc-99m tetrofosmin e.g. sestamibi. Count rates (cts/10 sec) were measured and used for calculating in situ - and ex situ - T/NT ratios. Results: In 9 out of 12 patients, adenoma could be detected on static images. Mean T/NT ratios for Tc-99m tetrofosmin were 1.29 for early and 1.23 for delayed images, respectively 1.39 and 1.23 for early and delayed Tc-99m sestamibi scan. Three cases could only be detected with SPECT reconstruction. 11 of 12 parathyroid adenomas could be confirmed intra-operatively. Conclusion: SPECT with Tc-99m labelled cationic complexes showed advantages in detection, precise localization and contrast over static scintigraphy and should therefore be performed at least in cases with poor or no uptake on static images to avoid failures in detection of deeply sited, dislocated glands or adenomas with low uptake. Intraoperative localization and confirmation of parathyroid adenoma with Tc-99m-labelled cationic complexes and a gamma probe is possible and may be useful in case of dys- or ectopic adenoma by influencing surgical approach and operating time.

SummaryDespite low specificity routine mammography is the method of choice to screen women for breast cancer. In addition high frequency ultrasonography (US) or magnetic resonance imaging (MRI) can improve breast cancer diagnosis. However there is a lack of conventional imaging to improve the high rate of false positive results that make biopsy or surgery necessary. Aim: The purpose of our study was to evaluate prospectively the sensitivity, specificity, PPV and NPV of scintimammography with a new cationic complex Tc-99m-tetrofosmin. Methods: Fourtyeight patients in whom mammography and/or high resolution ultrasonography (10MHz) revealed suspicious breast lesions were studied with Tc-99m-tetrofosmin scintimammography. In thirtyfour of them biopsy and/or surgery was performed for histological evaluation. After intravenous injection of 555 MBq Tc-99m-tetrofosmin dynamic images over three minutes (1 frame/10 sec.) planar images in anterior and lateral projections (5 min. p.i.) and SPECT imaging including 3-D-reconstruction (20 min. p.i.) were performed. Scintimammography was evaluated as negative, equivocal (+), probably (++) or definitely (+++) positive. Results: Scintimammography with Tc-99m-tetrofosmin was negative in 18 patients (17 t.n.; 1 f.n.) and positive in 16 patients (10 t.p., 6 f.p.). The false negative scintimammography was observed in a patient with infiltrating ductal carcinoma pT1, the false positive result in a patient with fibrocystic disease; all of the five fibroadenomas were also “false” positive. Sensitivity of Tc-99m-tetrofosmin scintimammography in this prospective study was 91 %, specificity 74%, PPV 63% and NPV 94%. Scintimammographic results in patients with suspicious breast lesion show, that Tc-99m-tetrofosmin accumulates in breast cancer as well as in fibroadenoma. However the high NPV of 94 % excludes breast cancer in suspicious mammographie lesions in a very high degree and therefore reduces the need of biopsy and/or surgery in most of these patients. Conclusion: Our first results show that scintimammography with Tc-99m-tetrofosmin might play a role as further diagnostic step before surgery for women in whom mammography and/or ultrasonography show suspicious lesions.

Summary Aim: The usefulness of the myocardial perfusion agent, Tc-99m-tetrofosmin (Myoview®) in the follow-up of differentiated thyroid carcinoma was evaluated in a clinical study of 15 patients, primary treated with thyroidectomy and high-dose I-131-therapy (2960-3700 MBq), 12 with suspected recurrence and metastases and three patients without any suspicion and compared with other non-specific tracers like TI-201 and Tc-99m-sestamibi. Method: Twelve patients with elevated thyroglobulin (Tg) levels of more than 10 ng/ml (group A), four of these had negative I-131 scans, and three patients with Tg levels less than 10 ng/ml (group B) were examined under TSH suppressive L-Thyroxine treatment. Whole body scans were taken with TI-201 (74 MBq; 20 min post injection), Tc-99m-sestamibi (370 MBq; 20-60 min post injection) and Tc-99m-tetrofosmin (370 MBq; 20-60 min post injection). Tumor/background ratios and optional time/activity analyses (up to 150 min post injection) were evaluated using the region of interest approach. Results: Compared with TI-201 (T/BG: 1.59, ± 0.396), Tc-99m-tetrofosmin showed slightly but not significant better T/BG ratios and detection rates (T/BG: 1.76, ± 0.345).Tc-99m-sestamibi (1.51, ± 0.31 p = 0.05) showea significantly lower values than Tc-99m-tetrofosmin. Conclusion: In the light of these results, scintigraphy with Tc-99m-tetrofosmin seems to be a possibly sensitive imaging modality in the follow-up of DTC with possible advantages concerning T/Bg ratio, background clearance, detection rate and dosimetry compared with TI-201 and Tc-99m-sestamibi, especially in patients with elevated Tg level and no iodine uptake , but further investigations are needed to confirm our preliminary results.

ZusammenfassungDie alleinige klinische Abklärung dementieller Zustandsbilder, so auch der senilen Demenz vom Alzheimertyp (SDAT), ist schwierig. Durch die Kombination von 99mTc-HMPAO-Gehirn-SPECT und Serumvitamin-B12-Bestimmung erwarteten wir eine Beschleunigung und Verbesserung der Diagnostik der SDAT. Von 116 Patienten, die in 4 Gruppen, entsprechend ihrem 99mTc-HMPAO-Verteilungsmuster eingeteilt worden waren, konnten bei 17 klinisch sehr wahrscheinlichen SDAT-Patienten bei 15 Auffälligkeiten mit Hinweis auf SDAT im Gehirn SPECT gefunden werden. Ein Teil der Patienten wies einen niedrig-normalen bzw. pathologisch niedrigen Vitamin-B12-Spiegel auf. Andere Untersuchungen würden durch die Kombination von Gehirn-SPECT und Serumvitamin-B12-Bestimmung nicht überflüssig werden, obwohl beide Untersuchungen Informationen lieferten, die die Zuordnung zur Diagnose SDAT erleichterten. Die zusätzliche Serumvitamin-B12-Bestimmung stellt keinen wesentlichen Mehraufwand dar.

ZusammenfassungIn Österreich wurde 1963 eine gesetzlich vorgeschriebene Speisesalzjodierung mit 10 mg KJ/kg eingeführt. Dennoch zeigten Untersuchungen zur Jodversorgung zwischen 1982 und 84 nach wie vor einen Jodmangel Grad I bis II. Dies führte 1990 zur Anhebung der Speisesalzjodierung auf 20 mg KJ/kg Vollsalz. Ziel der Untersuchung war es, die Jodversorgung und die Schilddrüsenvolumina von Schülern 3 Jahre nach Einführung der erhöhten Jodsalzprophlyaxe zu überprüfen. Durchgeführt wurde eine stichprobenartige Untersuchung an 734 Schülern der 1. bis 12. Schulstufe. Der Mittelwert der Harnjodidausscheidung betrug 121 ug/g Kr; dies bedeutet gebenüber den Voruntersuchungen von 1984 einen deutlichen Anstieg der Jodversorgung. Gegenüber den Vergleichsdaten zeigten die entsprechenden Altersgruppen geringere mittlere Schilddrüsenvolumina.

ZusammenfassungIn einer retrospektiven Studie haben wir anhand von 160 Patienten, die uns innerhalb eines Jahres zur differentialdiagnostischen Abklärung bekannter Leberherde zugewiesen wurden, die Treffsicherheit der szintigraphischen Methoden analysiert. Hämangiome lagen bei 77 Patienten vor. Die Bloodpool- szintigraphie ergab 66 richtig positive Befunde (Sensitivität 85%); wenn nur Herde über 2 cm Größe berücksichtigt wurden, erhöhte sich die Sensitivität auf 94%. Metastasen CEA-exprimierender Tumore lagen bei 42 Patienten vor. Die Anti-CEA-Immunszintigraphie zeigte 33 richtig-positive Befunde (Sensitivität 78,5%). Fokal-noduläre Hyperplasien hatten 3 Patientinnen, Adenome 6 Patientinnen. Bei den restlichen 32 Patienten fanden sich 4 hepatozelluläre Karzinome, 25mal Metastasen vorwiegend von Bronchus und Mammakarzinomen, 2mal Echinokokkuszysten und eine regressive Gallengangszyste.

ZusammenfassungDie Hemiagenesie der Schilddrüse stellt eine seltene angeborene Veränderung dar. Diese angeborene Variante der Schilddrüsenanlage wird in den meisten Fällen durch Auffälligkeiten der Funktion oder der Größe des vorhandenen Schilddrüsenlappens zufällig gefunden. Der Fall einer 57jährigen Frau mit einer Schilddrüsenhemiagenesie in Kombination mit einer Immunthyreopathie Basedow wird vorgestellt. Die Zuweisung der Patientin zur Untersuchung erfolgte wegen einer Schilddrüsenüberfunktion. Die erforderlichen diagnostischen Schritte zur Erstellung dieser beiden Schilddrüsenveränderungen waren ein 99m-Tc-Schilddrüsenszintigramm, Ultraschall und Laborparameter der Schilddrüse (fT4, TT3, bTSH, TAK, TPO, TRAK).

The AIM of this study was to determine the additional value of SPECT/CT in sentinel node scintigraphy in breast cancer. Furthermore, it was our question to determine, whether the low-dose computed tomography component (LD-CT) can be used for axillary lymph node staging of clinically negative patients.51 patients with invasive breast cancer3 cm in diameter were included in our prospective investigation. SPECT/CT was performed on a dedicated scanner 30 minutes after subareolar injection of (99m)Tc-Nanocoll. Axillary staging with CT(LD) was performed using standard CT-criteria. SLN were allocated to an axillary level using SPECT alone and SPECT/CT. Additionally, the number of SLN on CT(LD) corresponding to the scintigraphic hot node was notified for each patient and compared to the number of SLN found with the gamma probe.In 45/51 evaluable patients SLN could be localised in level I in 43 patients and in level II in two patients (all positive) using SPECT-CT, whereas a clear allocation could not be obtained by SPECT alone. The number of SLN was discrepant between SPECT and CT(LD) in 13/45 patients. The number of SLN detected with the gamma probe (n = 68) not significantly differed from the number of SLN detected by CT(LD) (n = 65) but was significantly higher than with SPECT (n = 51). CT(LD) yielded a sensitivity of 35.7%, a specificity of 83.9%, a positive predictive value (PPT) of 50%, a negative predictive value (NPV) of 74.3% and a diagnostic accuracy of 68.9% for axillary staging with CT(LD).The additional information of SPECT/CT allows a more accurate characterization of the SN concerning size, depth and anatomical location. CT(LD) when performed during (99m)Tc-Nanocoll sentinel-SPECT/CT is not suitable for axillary staging in breast cancer patients with clinical negative axilla due to its low sensitivity and moderate specificity. Therefore, it does not influence the decision for SNB or ALND. The limited resolution of SPECT leads to an underestimation of the number of SLN compared to CT(LD) and the gamma probe.

The aim of this study was to determine the additional value of SPECT/CT in sentinel node scintigraphy in breast cancer. Furthermore, it was our question to determine, whether the low-dose computed tomography component (LD-CT) can be used for axillary lymph node staging of clinically negative patients. Patients, methods: 51 patients with invasive breast cancer

Background: We report on a case of preoperative scintigraphic and intraoperative scintimetric confirmation of an ectopic parathyroid adenoma with Tc-99m Tetrofosmin in a 52-year old patient with persistent hyperparathyroidism after unsuccessful primary preoperative localization and reoperation. Methods: In preoperative localization study, dynamic, sequential static scans and SPECT of the neck and mediastinum were performed using Tc-99m Sestamibi and Tc-99m Tetrofosmin. Reoperation was performed by help of a hand-held gamma-probe for intraoperative scintimetric localization after preoperative injection of Tc-99m Tetrofosmin. Results: An ectopic adenoma could be detected preoperatively with both tracers. Tc-99m Tetrofosmin showed no significant difference in image quality vs. Tc-99m Sestamibi. The adenoma could also be detected scintimetrically by elevated count-rates. Conclusions: This case gives promise for Tc-99m Tetrofosmin to be a possible alternative in parathyroid imaging with similar imaging properties and slight theoretical advantages concerning background clearance, radiation exposure and constitution over Tc-99m Sestamibi. Intraoperative localization and confirmation of ectopic parathyroid adenoma, eventually with a geometrically adapted gamma-probe, seems to be possible. Whether there are significant advantages resulting in a possible reduction of operating time, should be evaluated in further studies.

ZusammenfassungEs wird über eine 73jährige Patientin mit dem sehr seltenen Fall eines Karzinoms berichtet, das sich in einer Ductus thyreoglossus-Zyste innerhalb einer Struma diffusa et nodosa entwickelt hatte. Zusätzlich bestand eine Immunthyreopathie Typ Basedow. Sonographische, röntgenologische, szintigraphische und histologische Befunde werden vorgestellt.

Summary: Background: The aim of this retrospective study was to evaluate the accuracy of fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG-PET) images, which were interpreted under daily routine conditions, in patients with Hodgkin's disease (HD) or non-Hodgkin lymphoma (NHL) for restaging after chemotherapy and/or radiotherapy. For this purpose, 18F-FDG-PET results were compared with morphological imaging methods and the patients’ clinical background. Methods: 121 PET images of 93 lymphoma patients (44 HD, 49 NHL) were investigated after chemotherapy/radiotherapy. For PET imaging, 160–200 MBq 18F-FDG was administered intravenously, followed by an infusion of 20 mg Furosemid in 250 mL saline. Whole-body 18F-FDG-PET images were obtained using a partial-ring PET scanner without attenuation correction. The morphological imaging consisted in computed tomography and ultrasound (CT/US) in all patients, additional MRI in some patients, and iliac crest biopsy in cases of suspicious bone marrow involvement. The standard of reference was composed of biopsy data, clinical status at the time of investigation, and follow-up of at least 12 months. The PET images were evaluated for their sensitivity, specificity and accuracy based on written reports, which were compiled from other imaging data and the clinical history of the patients. Results: Sensitivity, specificity, and accuracy of 18F-FDG-PET was 91 %, 81 %, and 85 %; of CT/US, 88 %, 35 %, 56 %, respectively. Major sources of error in 18F-FDG-PET were due to asymmetric muscular hypermetabolism and inflammatory lesions misinterpreted as persistent viable lymphoma tissue. Furthermore, secondary malignancies other than lymphomas were another reason for misinterpretations of 18F-FDG-PET studies. Conclusions:18F-FDG-PET showed a comparable sensitivity but a higher specificity and accuracy compared with CT/US. To achieve a high accuracy in 18F-FDG-PET, the nuclear medicine specialist needs imaging and clinical data as background information, which can only be acquired through close co-operation with the referring clinicians. Pharmacological muscular relaxation in the course of 18F-FDG-PET imaging may be advisable, as nonspecific muscular hypermetabolism was one of the problems at the image readings and a source of incorrect 18F-FDG-PET interpretations.

Retrospective evaluation of Tc-99m ciprofloxacin (infection) scintigraphy consecutively performed in a series of patients clinically suspected for peripheral osteomyelitis (OM), spondylodiscitis (SD) and fever of unknown origin (FUO).A total of 20 patients clinically suspected for OM (n = 12), SD (n = 3) and FUO (n = 5) were included in our retrospective analysis. The additional criterion was a positive 3-phase bone scan for OM, or a 2-phase bone scan in case of SD. Planar whole body scans and static acquisitions were performed 1 and 4 h after application of 370 MBq Tc-99m ciprofloxacin. In 10 patients with suspected OM, additional immunoscintigraphy using Tc-99m labelled monoclonal antibodies (Mab BW 250/183) was performed and the correlation of infection to bloodpool and antigranulocyte scintigraphy was analysed.OM: Bacterial infection was confirmed in 8 of 15 lesions. Infection demonstrated true positive (TP) results in 7 of 8, true negative (TN) results in 2 of 7, false positive (FP) results in 5 of 7 patients and one false negative (FN) result. A strong correlation could be demonstrated between T/NT ratios of infection and bloodpool Tc-99m medronate imaging (r = 0.84, 0.88) and between infection and BW 250/183 (r = 0.92, 0.90). Using a threshold of 2.0 for T/NT ratio, only TP results could be observed whereas a T/NT in the range of 1.0-2.0 could not discriminate between septic and aseptic inflammation. Concordant results with Mab BW 250/183 could only be observed in 5 of 10 patients (4 TP, 1 TN) by showing 4 FP and 1 FN lesions with IF.Non-specific uptake of infection can be observed in a variety of clinical situations with moderate uptake, by showing a strong correlation with blood-pool imaging. Nevertheless, intense uptake may be specific for septic inflammation.

The goal of this study was to assess the accuracy and limitations of ultrasound guided fine-needle aspiration biopsy (ug-FNAB) of solitary thyroid nodules.The ug-FNAB results of 538 patients with solitary thyroid nodules, who afterwards underwent thyroid surgery, were compared retrospectively with the histology. Patients with multinodular goiter were excluded from the study. Ug-FNAB was performed on growing and/or hypoechoic and/or hypofunctional nodules. The ug-FNAB results were grouped as follows: group 1: malignant (n = 44); group 2: malignancy cannot be ruled out (n = 173); group 3: non-malignant (n = 296), group 4: inadequate (n = 25).When the cytological results of group 1 and group 2 were interpreted as being malignant and those of group 3 as being benign, sensitivity, specificity and accuracy of ug-FNAB were 96.7%, 65.8% and 69.5% respectively. The 62 thyroid carcinomas (TC) biopsied presented in 59 cases a suspicious or malignant cytology (95.2%). The smallest TC diagnosed by ug-FNAB had a diameter of 0.5 cm and 36.4% of all papillary TCor = 1 cm displayed stage pT4. The histology verified a TC in 18 cases out of the 173 ug-FNABs in group 2. Non-malignant ug-FNABs were confirmed by histology in 294 patients (99.3%) in group 3. In 4.65% of the ug-FNABs inadequate material was aspirated.Nodules with non-suspicious ug-FNAB results can be safely followed-up by sonography, as the cytological diagnoses were verified in more than 99% by histology. Papillary TC can be diagnosed with ug-FNAB very accurately. As stage pT4 was present in more than one third of patients with papillary TCor = 1 cm, ug-FNAB is also recommended for thyroid nodules 0.5-1 cm in diameter located adjacent to the thyroid capsule. However, microfollicular proliferations remain the limitation of ug-FNAB, as the cytology cannot distinguish between benign adenoma and follicular TC.

In iodine-sufficient areas any thyroid nodule has to be regarded as potentially malignant, whereas in iodine-deficient areas (endemic goiter areas) thyroid nodules, even multinodular goiter, are frequent. The majority of thyroid nodules in an endemic goiter area can be regarded as being most likely benign and thus not all patients with multinodular goiter have to undergo surgery. The major diagnostic aim and challenge is the selection for surgery of only those patients who suffer from mechanical obstruction due to large goiter and those who present with nodules suspicious of malignancy. Thus, for these cases the question of accurately excluding or verifying malignancy is essential for the patient and the specialist of nuclear medicine or endocrinology. A variety of investigations may be used for the preoperative evaluation of thyroid nodules, although currently sonography and fine-needle biopsy have to be regarded as the key investigations to clarify preoperatively the dignity of thyroid nodules. The article presents the indications and limitations of the different methods in use for the evaluation of thyroid malignancy. The authors present a diagnostic algorithm for the preoperative evaluation of thyroid malignancy with special respect to problems occurring in a(n) (former) endemic goiter area.

A 46 years old man, who showed a painful and progressive deformity of the left radius, is presented. After some months a fracture within the affected bone area occurred. The diagnostic procedures including X-ray, MRI, scintigraphy and histology were controversial. Both fibrous dysplasia and Paget's disease of bone were suspected. The critical analysis of all results concluded that the most likely diagnosis was fibrous dysplasia. Unaware of the diagnostic discrepancies, the patient received a therapy with pamidronate 3 x 60 mg intravenously, which improved symptoms. After 14 months, the patient complained again about pain in the left radius. After a second therapy with pamidronate the patient currently exhibits no symptoms. The controversial diagnostic results and the applied therapeutic procedure are discussed.

We report a rare case of Turner's syndrome (UTS) due to a gonosomal mosaic 45,X0/46,XY with the main clinical feature of several fractures in the course of osteoporosis. The bone mineral density (BMD) of the lumbar spine and the hip measured by DXA showed osteoporosis. The other clinical investigations including laboratory parameters presented beside an estrogen deficiency due to primary amenorrhea, a small thyroid with hypothyroidism, increased renal calciuria and increased markers of bone metabolism. Beside the supplementation of estrogen and thyroid hormone deficits, only a combination of different bone-associated drugs could normalize the bone mineral density and the bone turnover. During a two years' follow-up period no further fractures occurred. Furthermore, theories regarding the occurrence of osteoporosis and other complex pathologies in UTS are discussed with the conclusion that osteopenia in UTS is probably based on a multifactorial genesis. Due to these complex pathologies during adulthood, patients with UTS should get multidisciplinary care in order to reduce morbidity and preserve quality of life.

Scintigraphy is routinely used in evaluating thyroid nodules. Functioning nodules are reported to have a low probability of being malignant. Therefore cancer should appear hypo-functioning or "cold" on scintiscan. The aim of the study was to compare the scintigraphic pattern in different tumor stages of thyroid carcinoma. In addition, sonographic results are evaluated. In 151 patients with thyroid carcinoma 99mTc-pertechnetate scans were evaluated retrospectively by a visual inspection scoring method (A = no significant uptake to D = nodular uptake superior to normal thyroid tissue). Planar images were taken using a small field thyroid gamma camera. There were 52 patients with pT1 carcinoma (2 x follicular and 50 x papillary). The mean tumor size was 0.56 +/- 0.26 cm. The scintigraphic results were A and B in 5.7% (n = 6), C in 73% (n = 38), D in 15.6% (n = 8). Out of 40 patients with pT2 carcinoma, 34 had a papillary, 6 a follicular histology. Mean tumor size was 1.66 +/- 0.49 cm. The scintiscan was A in 12.5% (n = 5), B in 32.5% (n = 13), C in 42.5% (n = 17) and D in 12.5% (n = 5). There were 11 patients with pT3 carcinoma (4 x papillary, 7 x follicular). The mean tumor size was 3.96 +/- 0.88 cm in diameter. Scintiscan was A in 72.7% (n = 8), C in 27.3% (n = 3). Among 48 patients with pT4 carcinoma (2 x follicular, 1 x nondifferentiated, 45 x papillary), scan was A in 41.6% (n = 20), B in 14.5% (n = 7), C in 33.3% (n = 16) and D in 10.4% (n = 5). Mean tumor size was 2.16 +/- 1.45 cm (7 carcinomasor = 1 cm, 23 x 1-2 cm, the remaining2 cm). Tumor size plays an important role in routinely used planar scintigraphy. Nodules greater than 2 cm in diameter tend to appear cold but microcarcinomas (or = 1 cm) are often indifferent on scan. Therefore, planar 99mTc-pertechnetate scintigraphy is of little value in evaluating small thyroid nodules. In order to diagnose small thyroid nodules, ultrasonography and ultrasonographically guided FNAB should be recommended as the initial diagnostic steps in clinical routine.

Hypofunctioning nodules on scintiscan using Tc-99m Pertechnetate or I-123 have a higher probability of malignancy compared to eu- or hyperfunctioning nodules. However, in the preoperative assessment of thyroid nodules, ultrasonography and ultrasonography guided fine needle aspiration biopsy play the most important role, especially for papillary thyroid cancer. The problem of differentiating follicular adenoma from highly differentiated follicular carcinoma however remains. Also the additional use of a multi tracer imaging strategy (Tl-201/Tc-99m subtraction scan, Tc-99m Sestamibi, Tc-99m Tetrofosmin dual phase scintigraphy) has not solved this problem. Although it is unlikely, the question whether FDG PET is able to give a better differentiation between benign and malignant tumours in the preoperative assessment of thyroid nodules is not answered up to now. In contrast to preoperative diagnostics, FDG PET is of great value in the postoperative follow up of differentiated thyroid cancer. In case of elevated serum thyroglobulin but negative I-131 WBS FDG PET is the method of choice to detect I-131 negative recurrences and metastases. FDG uptake in metastases from differentiated thyroid cancer is correlated to low differentiation and maybe bad prognosis. There is also evidence that FDG PET may have a role in the follow up of anaplastic and especially in medullary thyroid cancer in the future.

In the follow up of differentiated thyroid carcinoma (DTC) several scintigraphic methods are used in addition to the serum thyroglobulin and ultrasonography of the neck. Iodine-131 whole body scintigraphy (WBS), which is performed since many years, is able to detect iodine positive recurrence, lymph node metastases and distant metastases in a very specific way. However, the problem of I-131 WBS is the fact that only 67% of metastases from DTC accumulate iodine. Therefore non specific radionuclides like TI-201 or tracers such as Tc-99m Sestamibi or Tc-99m Tetrofosmin and new metabolic tracers like F-18 FDG were introduced in the diagnostic work up to detect iodine negative metastases as well. This study describes the comparison of different tracers in 35 patients with elevated thyroglobulin and suspicion of metastatic disease or already known metastases from DTC.

A case of Graves' disease occurring in a patient with hemiagenesis is presented. The detection of the rare occurrence of a congenital hemiagenesis is often made by either clinical symptoms of thyroid dysfunction or anatomical abnormalities such as nodular goiter. The symptoms of hyperthyroidism in the current case led to the diagnostic confirmation by scintiscanning and ultrasonography of an absent lobe. Anti-thyroid antibody studies documented the presence of Graves' disease within the remaining lobe.

In patients with suspicious breast lesions, scintimammography (SM) using Tc-99m tetrofosmin (TETRO) and hydroxymethylene-diphosphonate (HDP) and Gd-DTPA MRI were performed. For both TETRO and MRI sensitivity was 93% compared to 71% for HDP; specificity was lower for TETRO and HDP (71%) than for MRI (86%). This preliminary study shows that, in contrast to HDP, TETRO SM and Gd-DTPA MRI are of additional diagnostic value in diagnosing breast cancer.

Determination of thyroglobulin (Tg) levels, determined under endogenous thyroid-stimulating hormone stimulation after withdrawal of L-thyroxin treatment (off-T4), has been proven to be the most sensitive method for evaluation of patients with recurrent malignancy or distant metastases. This study uses a comparative approach between low-dose 131I scan and the previously reported highly sensitive 99mTc-tetrofosmin whole-body scintigraphy, using Tg-off-T4 as a basis for comparison.Fifty-eight consecutive patients of our follow-up program with primary thyroid carcinoma ablated with thyroidectomy and radioiodine therapy were examined after L-thyroxin withdrawal over 3-4 wk with 131I (185 MBq) and 99mTc-tetrofosmin whole-body scintigraphy and Tg determination (off-T4) within 5 days. Patients with Tg levels above 0.5 ng/ml were defined as Group A (n = 29). Group B (n = 29) comprised patients who had Tg levels (off-T4) below 0.5 ng/ml.Iodine-131 revealed only 19 of 44 tumor sites (43.18%). Additionally, three remnants could be demonstrated. Sensitivity showed decreasing values for local recurrences (4 of 7, 57.1%), bone lesions (7 of 13, 53.85%) and mediastinal (2 of 4, 50%), lung parenchymal (3 of 7, 42.85%) and lymph node (2 of 9, 22.2%) metastases. Whole-body scintigraphy with 99mTc-tetrofosmin revealed a total of 39 of 44 malignant lesions (88.6%). Sensitivity was superior for lung parenchymal metastases (9 of 9, 100%), mediastinum (4 of 4, 100%) and lymph nodes (9 of 10, 90%) and inferior for bone metastases (11 of 13, 84.6%). Local recurrences could be detected in 6 of 7 patients (85.7%), and thyroid remnants were detected in 2 cases (2 of 11, 18.2%). One liver metastasis could not be detected because of the physiologic tracer distribution of 99mTc-tetrofosmin. Thyroglobulin-off-T4 detected malignant recurrence or metastases in 18 of 19 patients (94.7%) when a cutoff of 3 ng/ml was used and in 16 of 19 patients (84.2%) when a cutoff of 10 ng/ml was used. Specificity was calculated as 71.8% when a cutoff of 0.5 ng/ml was used, 89.7% when a cutoff of 3 ng/ml was used and 100% when a cutoff of 10 ng/ml was used.Scintigraphy with 99mTc-tetrofosmin showed clear advantages concerning sensitivity in most metastatic lesions when compared with low-dose 131I scan. Despite a slight lower specificity, 99mTc-tetrofosmin whole-body scintigraphy has, therefore, been proven to be a useful tool in the assessment of metastatic lesions in differentiated thyroid carcinoma.

We report a case of a 48-yr-old woman who underwent surgery because of papillary oxyphilic thyroid carcinoma pT3. After total thyroidectomy, we administered 2960 MBq (131)I for ablation of the residual tissue. initial follow-up visits showed no clinical, radiological or scintigraphic evidence of residual or metastatic thyroid tissue. Serum thyroglobulin levels (Tg) and (131)I whole-body scintigraphy were negative. Three years after thyroidectomy, the patient experienced seizures, and as a consequence a brain tumor was removed. It was an undetected metastasis of the primary thyroid carcinoma. Histological examinations showed that neither the primary tumor nor the metastasis produced any Tg. With this fact in mind and the knowledge of negative (131)I whole-body scans we had to concentrate on radiological (CT and MRI scans) and nonspecific scintigraphic methods such as 201TI whole-body scintigraphy in our management of the patient. Further follow-up demonstrated multiple metastasis by 201TI whole-body scan (mediastinum, bones and soft tissue), and most of them have been removed by surgery. This case report demonstrates that, in addition to (131)I whole-body scans and measurement of serum Tg, the use of nonspecific tracers like 201TI is important to detect (131)I and/or Tg negative metastases.

The aim of the study was to evaluate the influence of human anti-mouse antibodies on the measurement of thyrotropin.Samples from 11 patients with measureable human anti-mouse antibody titres (19 micrograms/l-3880 micrograms/l) after radioimmuno-scintigraphy were analysed with 6 different thyrotropin immuno-radiometric assay kits (IRMA). Each sample was analysed in the routine way (sample influenced by human anti-mouse antibodies), as well as after incubation with murine immunoglobulin to precipitate human anti-mouse antibodies (samples not influenced by human anti-mouse antibodies).Two kits showed clear deviations of measured thyrotropin levels when the human anti-mouse antibody titres were higher than 1350 micrograms/l. A third kit was influenced to a lesser extent by human anti-mouse antibodies. Three of the 6 investigated thyrotropin IRMA kits produced thyrotropin values that were unaffected by the presence of elevated human anti-mouse antibodies. In comparison with former studies after immunotherapy, the thyrotropin deviations were marginal. However, differences were found between the commercially available thyrotropin assays. According to the results of this study only three out of the six investigated kits were unaffected by human anti-mouse antibodies.Since thyrotropin is one of the key quantities for the endocrinologist dealing with the thyroid gland, every laboratory should ensure high quality thyrotropin assays by critically analysing their method for human anti-mouse antibody.

The uptake of 99mTc-tetrofosmin in enlarged lymph nodes, of the lung hilus, in the case of sarcoidosis Stage I (histopathologically confirmed by mediastinoscopic biopsy) is demonstrated. On a routine chest radiograph of a 78-yr-old woman, hilar lymphadenopathy was first detected. In the following mammography, disseminated micro calcifications were found in the left breast and a 99mTc-tetrofosmin study was performed for detection of breast cancer. Scintigraphy using 99mTc-tetrofosmin showed clear uptake in the hilar lymph nodes, but not in the left breast. The 99mTc-tetrofosmin uptake in the hilar lymph nodes was due to sarcoidosis confirmed by histology. Therefore, 99mTc-tetrofosmin scintigraphy may be useful in patients with suspected sarcoidosis, especially in Stage I.

A 73-year-old patient presented a 99mTc scintiscan with a focal tracer accumulation left and caudal of the thyroid gland. Further investigations with sonography, CT, esophagoscopy and barium swallow provided the diagnosis of achalasia as the reason for focal 99mTc retention caudal of the thyroid gland. Explanation for 99mTc accumulation within the esophagus may be the nonspecific accumulation of 99mTc not only in the thyroid gland but also in the salivary glands. Excretion of the tracer follows with the saliva. Structural and motor disorders of the esophagus can thus lead to focal tracer retention within the esophagus simulating thyroid tissue.

The purpose of this study was to evaluate prospectively the reliability of the new nonspecific tumor-searching tracer tetrofosmin in the postoperative follow-up of differentiated thyroid carcinoma (DTC) during TSH suppressive thyroid hormone treatment.Whole-body scintigraphy was performed in 114 patients under TSH suppressive L-T4 treatment 20 min after intravenous injection of 370 MBq 99mTc-tetrofosmin by means of a dual-head gamma camera followed by three-dimensional SPECT in case of suspicious tracer uptake. The results of serum thyroglobulin, ultrasonography of the neck, 131I whole-body scintigraphy, chest radiograph, transmission CT or MRI, and bone scintigraphy were also available.A group of 68 patients without thyroid remnants who were tumor free and had no history of metastases or tumor recurrence showed a negative 99mTc-tetrofosmin whole-body scan. Another 24 patients (papillary carcinoma pT1NOMO) were also in complete remission, but had sonographically proven remnants (echonormal). Sixteen of them (67%) exhibited 99mTc-tetrofosmin accumulation in the thyroid bed, which corresponded excellently to the localization of the remnant. The third group comprises seven cases of local recurrence confirmed by histopathology after reoperation or by cytology after fine-needle aspiration where tetrofosmin scintigraphy clearly revealed relapse of malignancy in all cases. A total of 17 patients had distant metastases (11 pulmonary, 3 bone, 2 bone and pulmonary, 1 bone and soft tissue) discovered by different modalities, resulting in 44 lesions to be evaluated. Of the 23 radioiodine negative metastases, 17 were detected by tetrofosmin (74%), whereas all 21 radioiodine accumulating lesions also showed tetrofosmin positive scans. The overall sensitivity of 99mTc-tetrofosmin in detecting distant metastatic lesions was 86%. Four additional cases with radioiodine-negative disseminated lung metastases showed diffuse pulmonary tetrofosmin uptake.Technetium-99m-tetrofosmin is a promising tracer to detect malignant recurrence and distant metastases in the follow-up of DTC without the necessity of thyroid hormone withdrawal.

The aim of our study was to evaluate the possibility of intraoperative scintimetric detection of parathyroid adenomas with Tc-99m labelled tracers for its usefulness in dystropic or ectopic adenomas.12 women with biochemically confirmed hyperparathyroidism were included in our study. After injection of 370 MBq Tc-99m tetrofosmin e.g. sestamibi, preoperative scintigraphy (double phase study and SPECT) was performed and T/NT ratios were evaluated for early, delayed and SPECT images. Surgery was performed using a hand-held gamma-probe after preoperative injection of 555-925 MBq Tc-99m tetrofosmin e.g. sestamibi. Count rates (cts/10 sec) were measured and used for calculating in situ- and ex situ-T/NT ratios.In 9 out of 12 patients, adenoma could be detected on static images. Mean T/NT ratios for Tc-99m tetrofosmin were 1.29 for early and 1.23 for delayed images, respectively 1.39 and 1.23 for early and delayed Tc-99m sestamibi scan. Three cases could only be detected with SPECT reconstruction, 11 of 12 parathyroid adenomas could be confirmed intra-operatively.SPECT with Tc-99m labelled cationic complexes showed advantages in detection, precise localization and contrast over static scintigraphy and should therefore be performed at least in cases with poor or no uptake on static images to avoid failures in detection of deeply sited, dislocated glands or adenomas with low uptake. Intraoperative localization and confirmation of parathyroid adenoma with Tc-99m labelled cationic complexes and a gamma probe is possible an 1 may be useful in case of dys- or ectopic adenoma by influencing surgical approach and operating time.

Especially ectopic adenomas may be problematic in intraoperative localization despite preoperative imaging resulting in a longer operating time and more extensive surgical preparation. The aim of our study was to evaluate the possibility of intraoperative scintimetric detection of parathyroid adenomas with cationic, Tc-99m labelled tracers for its usefulness in ectopic adenomas. 12 women with biochemically confirmed hyperparathyroidism were included in our study. After injection of 370 MBq Tc-99m Tetrofosmin respectively Sestamibi, preoperative scintigraphy (double phase study and SPECT) was performed and T/NT ratios were evaluated for early, delayed and SPECT images. Surgery was performed using a hand-held gamma probe after preoperative injection of 555-925 MBq Tc-99m Tetrofosmin or Sestamibi. Count rates (cts/10 sec) were measured and used for calculating in situ- and ex situ-T/NT ratios. In 9 out of 12 patients, adenoma could be detected on static images. Three cases could only be detected with SPECT. 11 of 12 parathyroid adenomas could be confirmed intraoperatively. Intraoperative localization of parathyroid adenoma with Tc-99m-labelled cationic complexes and a gamma probe is possible and may be useful in case of ectopic adenoma by influencing surgical approach and operating time.

Technetium-99m-methoxyisobutylisonitrile (MIBI) was introduced for myocardial imaging as an alternative to 201TI. According to biodistribution studies, MIBI also accumulates in the thyroid gland. The aim of this study was to find out which thyroid nodules retain MIBI and whether preoperative evaluation of malignancy is possible.Single injection, dual-phase (30 min and 2 hr) thyroid scintigraphy with 99mTc-MIBI was performed on 62 patients who showed a cold nodule on previously performed 99mTc scintigraphy. MIBI scans were considered positive if there was a clear tracer retention in the late 120-min image compared to the early 30-min image. Sonographic examination and fine-needle aspiration biopsy, guided by ultrasonography, was also done on each patient. In the following days and weeks, all patients underwent surgery.Histopathological diagnoses revealed a total of 12 thyroid carcinomas, five were MIBI positive and seven MIBI negative. Out of 27 patients with thyroid adenomas (nine microfollicular, ten follicular, eight oxyphilic), 18 were MIBI positive and nine MIBI negative. There was no MIBI retention on the scans of 22 patients with degenerative changes in the goiter and the one with Hashimoto's disease.These results indicate that MIBI accumulation and retention is not specific for thyroid malignancy. Indeed, all evidence points to the fact that a positive MIBI scan is more likely to indicate thyroid adenoma than a malignant tumor.

Despite low specificity routine mammography is the method of choice to screen women for breast cancer. In addition high frequency ultrasonography (US) or magnetic resonance imaging (MRI) can improve breast cancer diagnosis. However there is a lack of conventional imaging to improve the high rate of false positive results that make biopsy or surgery necessary.The purpose of our study was to evaluate prospectively the sensitivity, specificity, PPV and NPV of scintimammography with a new cationic complex Tc-99m-tetrofosmin.Fourtyeight patients in whom mammography and/or high resolution ultrasonography (10 MHz) revealed suspicious breast lesions were studied with Tc-99m-tetrofosmin scintimammography. In thirtyfour of them biopsy and/or surgery was performed for histological evaluation. After intravenous injection of 555 MBq Tc-99m-tetrofosmin dynamic images over three minutes (1 frame/10 sec.) planar images in anterior and lateral projections (5 min. p.i.) and SPECT imaging including 3-D-reconstruction (20 min. p.i.) were performed. Scintimammography was evaluated as negative, equivocal (+), probably (+2) or definitely (+3) positiveScintimammography with Tc-99m-tetrofosmin was negative in 18 patients (17 t.p., 1 f.n.) and positive in 16 patients (10 t.p., 6 f.p.). The false negative scintimammography was observed in a patient with infiltrating ductal carcinoma pT1, the false positive results in a patient with fibrocystic disease; all of the five fibroadenomas were also "false" positive. Sensitivity of Tc-99m-tetrofosmin scintimammography in this prospective study was 91%, specificity 74%, PPV 63% and NPV 94%. Scintimammographic results in patients with suspicious breast lesion show, that Tc-99m-tetrofosmin accumulates in breast cancer as well as in fibroadenoma. However the high NPV of 94% excludes breast cancer in suspicious mammographic lesions in a very high degree and therefore reduces the need of biopsy and/or surgery in most of these patientsOur first results show that scintimammography with Tc-99m-tetrofosmin might play a role as further diagnostic step before surgery for women in whom mammography and/or ultrasonography show suspicious lesions.

The usefulness of the myocardial perfusion agent, Tc-99m-tetrofosmin (Myoview) in the follow-up of differentiated thyroid carcinoma was evaluated in a clinical study of 15 patients, primary treated with thyroidectomy and high-dose I-131-therapy (2960-3700 MBq). 12 with suspected recurrence and metastases and three patients without any suspicion and compared with other non-specific tracers like TI-201 and Tc-99m-sestamibi.Twelve patients with elevated thyroglobulin (Tg) levels of more than 10 ng/ml (group A), four of these had negative I-131 scans, and three patients with Tg levels less than 10 ng/ml (group B) were examined under TSH suppressive L-Thyroxine treatment. Whole body scans were taken with Tl-201 (74 MBq: 20 mn post injection), Tc-99m-sestamibi (370 MBq: 20-60 min post injection) and Tc-99m-tetrofosmin (370 MBq: 20-60 min post injection). Tumor/background ratios and optional time/activity analyses (up to 150 min post injection) were evaluated using the region of interest approach.Compared with Tl-201 (T/BG: 1.59, +/- 0.396). Tc-99m-tetrofosmin showed slightly but not significant better T/BG ratios and detection rates (T/BG: 1.76, +/- 0.345). Tc-99m-sestamibi (1.51, +/- 0.31 p = 0.05) showed significantly lower values than Tc-99m-tetrofosminIn the light of these results, scintigraphy with Tc-99m-tetrofosmin seems to be a possibly sensitive imaging modality in the follow-up of DTC with possible advantages concerning T/Bg ratio, background clearance, detection rate and dosimetry compared with Tl-201 and Tc-99m-sestamibi, especially in patients with elevated Tg level and no iodine uptake, but further investigations are needed to confirm our preliminary results.

Since many years TI-201, as non-specific tumor-searching radionuclide, plays a certain although somewhat controversial role in the follow-up of differentiated thyroid carcinoma (DTC). Recently some Tc-99m labeled myocardial perfusion agents were introduced, that might be more important for nuclear oncology in the future. Aim of this study was to evaluate prospectively the reliability of the new non-specific tumor searching tracer tetrofosmin (Myoview) in the post operative follow-up of differentiated thyroid carcinoma during TSH suppressive thyroid hormone treatment and to compare the results in patients with metastasizing DTC to Tc-99m sestamibi (Cardiolite) and TI-201. In a pilot study 12 patients with elevated thyroglobulin (Tg) levels of more than 10 ng/ml and known metastatic disease were examined under TSH suppressive L-Thyroxine treatment comparing TI-201, Tc-99m sestamibi and Tc-99m terofosmin whole body scintigraphy (WBS). Furthermore in 146 consecutive follow up patients tetrofosmin WBS was performed under TSH-suppressive L-T4 treatment. The results were compared to serum thyroglobulin (Tg), ultrasonography (US) of the neck, I-131 whole body scintigraphy (I-131 WBS), transmission computed tomography (TCT) or magnetic resonance imaging (MRI) and bone scintigraphy. Whole body scans were performed with TI-201 (74 MBq; 20 min post injection), Tc-99m sestamibi (370 MBq; 20-60 min post injection) and Tc-99m tetrofosmin (370 MBq; 20-60 min post injection). Tumor/background ratios and optional time/activity analyses (up to 120 min post injection) were evaluated using the region of interest approach. In the pilot study tetrofosmin showed the highest T/BG ratios and detection rates (T/BG: 1.76 +/- 0.345) followed by TI-201 (T/BG: 1.59 +/- 0.396) and sestamibi (1.51 +/- 0.31 p = 0.05). From the 146 patients investigated consecutively with Tc-99m tetrofosmin WBS for the routine follow up of DTC, 88 patients (no thyroid remnants, no history of metastases or tumor recurrence) were tumor free. All of them resulted in negative Tc-99m tetrofosmin WBS. Another 32 patients (papillary carcinoma pT1) were also in complete remission, but had sonographically proven remnants (echonormal). Twenty one of them exhibited certain Tc-99m tetrofosmin accumulation in the thyroid bed. In 9 cases with local recurrence as confirmed by histopathology after reoperation or by cytology after fine needle aspiration, the tetrofosmin scintigraphy clearly revealed relapse of malignancy including 2 patients with tetrofosmin positive additional distant metastases. Seventeen patients had distant metastases (11 pulmonary, 3 bone, 2 bone and pulmonary, 1 bone and soft tissue) detected by different modalities and resulting in a total of 44 lesions to be evaluated. In the 23 radioiodine negative metastases, 17 were also detected by tetrofosmin (74%). In the 21 radioiodine accumulating lesions 19 were Tc-99m tetrofosmin positive (90%). Four cases with radioiodine negative disseminated lung metastases showed diffuse pulmonary tetrofosmin uptake. This prospective study shows that Tc-99m tetrofosmin is a new promising tracer to detect malignant recurrence and distant metastases in the follow up of DTC without the necessity of thyroid hormone withdrawl, especially in patients with elevated Tg level and no iodine uptake. Tc-99m tetrofosmin shows slight advantages concerning T/Bg Ratio, background clearance, detection rate and dosimetry compared with TI-201 and Tc-99m sestamibi.