[Colour-coded duplex-sonography versus scintigraphy. Can scintigraphy be replaced by sonography for diagnosis of functional thyroid autonomy?]. / 99mTc-Szintigraphie versus Farbduplex-Sonographie. Kann zur Diagnose der funktionellen Schilddrüsenautonomie auf die Szintigraphie verzichtet werden?

UNLABELLED: Since the development of colour coded duplex-sonography (ccds), several attempts have been made to implement this technique for diagnosis of focal lesions in the thyroid. There are controversial discussions on whether ccds might replace thyroid scintigraphy in diagnosis of hyperfunctional thyroid nodules. Aim of this study was the comparison of ccds and thyroid scintigraphy in diagnosis of functional thyroid autonomy. PATIENTS, MATERIAL AND METHODS: 192 patients with thyroid nodules > 10mm detected by conventional sonography underwent thyroid scintigraphy. Additionally, these patients were subjected to ccds of the thyroid. In total, 286 thyroid nodules were examined by scintigraphy, ccds and blood tests. RESULTS: Thyroid scintigraphy showed 67% of thyroid nodules as hyperfunctional, 19% indifferent and 14% as hypofunctional. Mean 99mTc uptake of hyperfunctional nodules was 2.19%, of indifferent nodules 1.12% and of hypofunctional nodules 1.06% respectively. The ccds allowed perinodular measurement of flow speed (hyperfunctional: 0.23 ± 0.1 m/s; hypofunctional: 0.22 ± 0.1; indifferent: 0.21 ± 0.09), resistance index (hyperfunctional: 1.21 ± 1.16; hypofunctional: 0.62 ± 0.48; indifferent: 0.93 ± 1.02) and pulsatility index (hyperfunctional: 0.97 ± 0.45; hypofunctional: 0.84 ± 0.4; indifferent: 1.04 ± 0.6) in all nodules as well as intranodular measurement in some of the nodules (24% in hyperfunctional, 2% in indifferent and 15% in hypofunctional nodules). Statistic analysis of the obtained ccds data did not show any practically relevant correlations (p>0.05) with 99mTc uptake, basal TSH, fT3 or fT4. CONCLUSION: Thyroid scintigraphy cannot be replaced by ccds for diagnosis of functional thyroid autonomy. Reliable diagnostics still require a combination of thyroid scintigraphy, sonography and blood tests.

[Scintigraphically "hot" thyroid nodules mainly go hand in hand with a normal TSH]. / Szintigraphisch mehranreichernde Schilddrüsenknoten gehen überwiegend mit normwertigem TSH einher.

AIM: In recent years, various professional societies published guidelines for diagnostic evaluation of thyroid nodules, in which the indication for scintigraphy is restricted to patients with subnormal TSH values. It is seen controversial whether such recommendations should be transferred to Germany, partly because of lower iodine intake in this country and the consequent higher percentage of autonomous thyroid nodules, which are not accompanied by a measurable dysfunction. Since reliable data to this topic are scarce, we analyzed multicentrically the spectrum of scintigraphically "hot" and "warm" nodules under the current epidemiological conditions. PATIENTS, METHODS: In 10 German nuclear medicine out-patient institutions we evaluated the diagnostic data from a total of 514 patients, in whom unequivocally hyperfunctional nodules (focal increased uptake in comparison to perinodular tissue with a sonographically nodular correlative ≥1 cm) could be detected by (99m)Tc-pertechnetate scintigraphy. To minimize selection bias, the surveys were not carried out in hospitals.The recorded parameters included the thyroid hormone levels, the global (99m)Tc-uptake (TcTU), the size of each nodule and the total autonomous nodular volume (V(aut)). RESULTS: Only 20% of the patients with "hot" nodules had subnormal TSH levels (<0.1 to 0.33 mU / l), the remaining patients had TSH levels from 0.34 to 3.5 mU /l (in one third of the patients TSH levels even exceeded 1.0 mU/l). Moreover, we found no relevant correlation between TSH and TcTU or V(aut). CONCLUSIONS: In Germany, in at far the largest proportion of patients with autonomous thyroid nodules objectified by means of scintigraphy, TSH levels are within the normal range. Since such nodules with maximum safety can be classified as benign, a corresponding scintigraphic finding has a high priority for the patient. These current data support that it is not reasonable to restrict scintigraphy to patients with subnormal TSH values in this country.

Multiparameter scoring system for the prognosis of differentiated thyroid cancer.

UNLABELLED: The AIM of the study was to develop a scoring system consisting of multiple parameters that are significant for prognosis of thyroid cancer. The score was designed to permit a risk stratification with all available information at any time of presentation. PATIENTS, METHODS: A score using 25 parameters was used for 171 patients with differentiated thyroid cancer, who were included in follow up over a mean of 9 (+/- 5) years. The significance of each parameter as well as of a summation outcome score was determined. The result of this scoring system was compared to other scores reported in the literature applied to the same patients' group. Thirty-two out of the 171 patients presented with recurrence during follow up. RESULTS: The summation score was highly significant for prognosis of differentiated thyroid cancer. Out of 25 parameters, 18 showed a significant association with outcome also as individual parameters. In comparison to the scores commonly used, this new system showed the highest significance (p < 0.0001, chi square 90, df 1) to estimate recurrence free survival. At a cutoff of -5.95 the sensitivity and specificity for the distinction between high and low risk patients were 87.5 and 77.0%, respectively. CONCLUSION: With our multiparameter scoring system a reliable prognosis with respect to recurrence free survival is possible in patients suffering from differentiated thyroid cancer. A summation score of all parameters gives the best results. Scoring is also possible, if several important parameters are missing.

[Positron emission tomography with (18)F-fluoro-2-deoxyglucose in cardiological diagnosis].

This clinically oriented review presents main principles of metabolism of cardiac muscle, pathophysiology of myocardial hibernation and stunning, as well as methodological principles of positron emission tomography (PET) of the heart with (18)F-fluoro-2-deoxyglucose ((18)F-FDG). Diagnostic and prognostic value of (18)F-FDG PET and scintigraphic sings of disturbed myocardial viability, contractility and metabolism are also described. Efficacy of (18)F-FDG PET is compared with other imaging methods such as radionuclide, ultrasound and radiological. Literature data and clinical cases demonstrate importance of preoperative diagnosis of hibernating myocardium in patients with ischemic heart disease. (18)F-FDG PET is a basic method of detection of potentially reversible pathological states of the heart (hibernation and stunning); it has high sensitivity and specificity as well as predictive power in relation to forthcoming course of ischemic heart disease. This noninvasive method of investigation provides unique information on severity of ischemic heart disease for stratification of patients in risk groups and selection of candidates for coronary artery bypass surgery or cardiac transplantation.

Increased FDG bone marrow uptake after intracoronary progenitor cell therapy.

UNLABELLED: Patients with coronary artery disease who undergo FDG, PET for therapy monitoring after intracoronary progenitor cell infusion (PCT) show an increased bone marrow uptake in some cases. AIM of the study was to evaluate the systemic bone marrow glucose metabolism in this patient group after PCT. PATIENTS, METHODS: FDG bone marrow uptake (BMU), measured as standardized uptake value (SUVmax) in the thoracic spine, was retrospectively evaluated in 23 control patients who did not receive PCT and in 75 patients who received PCT 3 +/- 2.2 days before PET scanning. Five out of them were pretreated with granulocyte colony-stimulating factor (G-CSF) 5 days prior to PCT and 10 +/- 1.2 days before PET scanning. In 39 patients who received only PCT without G-CSF and underwent PET therapy monitoring 4 months later, baseline and follow up bone marrow uptake were measured. Leucocytes, C-reactive protein (CRP) levels and the influence of nicotine consumption were compared with the BMU. RESULTS: In patients (n = 70) who received PCT without G-CSF, BMU median (1.3) was slightly, but significantly higher than in the controls (1.0) (p = 0.02) regardless nicotine consumption. BMU did not change significantly 4 months later (1.2) (p = 0.41, n.s.). After G-CSF pretreatment, patients showed a significantly higher bone marrow uptake (3.7) compared to patients only treated with PCT (1.3) (p = 0.023). Leucocyte blood levels were significantly higher in patients with a BMU > or =2.5 compared to patients with a bone marrow SUVmax <2.5 (p<0.001). CRP values did not correlate with the BMU (rho -0.02, p = 0.38). CONCLUSION: Monitoring PCT patients, a slightly increased FDG BMU may be observed which remains unchanged for several months. Unspecific bone marrow reactions after PCT may be associated with increased leucocyte blood levels and play a role in the changed systemic glucose BMU. In addition, pretreatment with G-CSF shows an intense amplification of BMU.

Residual kidney function after donor nephrectomy. Assessment by 99mTc-MAG3-clearance.

AIM: We evaluated the long-term residual renal function after donor nephrectomy using 99mTc-mercaptoacetyltriglycin (MAG3)-clearance. DONORS, METHODS: Altogether 49 kidney donors were examined using 99mTc-MAG3-clearance after nephrectomy for donation to a relative (m:f = 11:38; age 55+/-27 years). The donors were examined 16+/-8 years postoperatively (1.5-26 years). 42 donors (86%) showed normal creatinine values, whereas the other seven (14%) exhibited slightly elevated levels. 20 donors were examined pre- and postoperatively and compared intraindividually. The kidney function was compared to the age adapted normal values of healthy persons with two kidneys (67-133% of age related mean). RESULTS: After nephrectomy all donors showed a normal perfusion, good secretion, merely physiological intrarenal transit and a normal elimination from the kidneys. The 99mTc-MAG3-clearance was 69+/-15% of the normal mean value of healthy carriers of two kidneys regardless of the gender. 20 donors with a preoperative examination showed a significantly reduced total renal function from 84+/-15% of the mean normal value preoperatively to 60+/-15% postoperatively (p <0.0005). 15 donors of this group exhibited a significant functional increase of the residual kidney from 40% initially to 60% after nephrectomy (p = 0.003). No correlation was found between the initial-99mTc-MAG3-clearance measured prior to nephrectomy and the clearance levels after nephrectomy. Also, no correlation between the preoperative 99mTc-MAG3-clearance and the postoperative serum creatinine values could be observed. Altogether, 22% of the donors (11/49) developed arterial hypertension 10+/-8 years after donation (1-23 years). This corresponds to the normal age prevalence of hypertension in the carriers of two kidneys. Three donors suffered from arterial hypertension prior to the operation. CONCLUSION: Kidney donors with normal or slightly elevated creatinine values postoperatively show a 99mTc-MAG3-clearance value of 69% of the mean value of healthy carriers of two kidneys. This may serve as a reference value for healthy carriers of one kidney. In our study we demonstrated a good compensation of the contralateral kidney via renal scintigraphy by means of 99mTc-MAG3-clearance.

Case report: drug interference with MIBG uptake in a patient with metastatic paraganglioma.

Metaiodobenzylguanidine (MIBG) labelled with iodine-131 ((131)I) has become a well established therapeutic tool for inoperable metastastic tumours of paraganglioma. There are different pharmacological substances known to interfere with MIBG-uptake which may result in a false negative MIBG scan. We present the case of a 26-year-old male polytoxicomanic patient with metastatic paraganglioma, who underwent MIBG therapy. During earlier therapies, MIBG uptake in the metastatic lesions was very high. A post-therapeutic whole-body scan subsequent to recent (131)I-MIBG therapy failed to detect the vast majority of metastatic lesions-except for two. (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) showed metastases with a similar distribution to the initial MIBG scan. The possible reasons for the discrepancy in the findings of the MIBG scans and the (18)F-FDG-PET scan are discussed with special emphasis on drug intake prior to MIBG administration, increased MIBG turn-over and unknown drug mixture interference with MIBG uptake.

The influence of thyroglobulin on functional imaging in differentiated thyroid cancer.

AIM: Recombinant human thyroid stimulating hormone (rhTSH) for an exogenous stimulation of TSH and consequent thyroglobulin (hTG) synthesis has reinitiated a discussion about the usefulness of diagnostic procedures for the follow-up of differentiated thyroid cancer (DTC). METHOD: Fifty consecutive patients with DTC who received whole-body iodine scintigraphy (WBS) and positron emission tomography (PET) were evaluated. RESULTS: The work-up was normal in 18/50. In 32 patients, functional imaging detected DTC. In 44% exogenous TSH stimulation with rhTSH was used and thyroxin was withdrawn in the others. The hTG under stimulation ranged from 0.8 to 5.004 ng x ml(-1). It was below 2 ng x ml(-1) in four (12.5%) patients. In total, 91 tumour sites were identified by positron emission tomography (PET) and 47 sites by WBS. PET and WBS showed corresponding uptake in 38% of lymph node, 48% of parenchymal and 43% of bone metastases. PET detected additional 53% of lymph node (WBS 9%), 38% of parenchymal (WBS 14%) and 28.5% of bone metastases. CONCLUSION: It is concluded that PET is more sensitive than WBS for the detection of DTC. The follow-up of DTC patients with hTG levels alone misses a significant number of true positive cases. Its use should therefore be restricted to selected low risk patients only.

Subclinical hyperthyroidism in dementia and correlation of the metabolic index in FDG-PET.

AIM: Thyroid hormone status and thyroid antibodies were evaluated in patients suffering from dementia for further study of an association of hyperthyroidism with AD and vascular dementia (VD), respectively. PATIENTS: In 77 patients with dementia, and 42 controls, thyrotropin (TSH) and thyroid antibodies were correlated with the different types of dementia and the metabolic index (MI) based on imaging with F-18-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET). RESULTS: Twenty-two of all patients with dementia (29%) had borderline (TSH 0.3-0.5 mU/l) or decreased TSH levels (TSH < 0.3 mU/L). TSH values were significantly lower in patients suffering from AD (median: 1.1 mU/l) and VD (0.5 mU/l) than in the control group (1.5 mU/l) (p < 0.01). Decreased or borderline TSH levels were present in 52% of the patients with VD, but in only 10% of the controls, and in 23% of the patients with AD. Antibodies to thyroid peroxidase were positive in 16% of all patients with dementia. The MI in patients suffering from AD with borderline TSH levels was 0.81 (0.70, 0.94). In contrast, patients suffering from AD with normal TSH values showed a slightly higher MI of 0.84 (0.76, 0.89) (p = n.s.). CONCLUSION: Decreased or borderline TSH values are associated with an increased probability of having dementia, especially VD.

[Positron-emission tomography in oncology]. / Pozitronno-émissionnaia tomografiia v onkologii.

This review analyses clinical results, new trends and recommendations of the leading medical centers concerning application of positron-emission tomography (PET) with F-18 fluorodeoxyglucose (F18 FDG) in cancer patients. This method of radionuclide visualization has been widely introduced for the last decade in diagnosis of cancer of unknown primary location, or CUP-syndrome, bronchogenic cancer of the lungs, cancer of the head and neck, malignant lymphoma and melanoma, colorectal and neuroendocrine cancer. Efficacy of this procedure, physiological grounds, performance are considered. Potentialities of F18 FDG PET are demonstrated in tumor screening, detection of metastases, recurrences after surgical, radiation or drug antitumor treatment or monitoring. In combination with CT, MRT, USI and other techniques, F18 FDG PET raises accuracy of the diagnosis of pathological changes at any stage of cancer with resulting improvement in further therapeutic and follow-up efficacy.