[The thyroid gland in old age : Physiology and pathology]. / Die Schilddrüse im Alter : Physiologie und Pathologie.

In healthy older people the metabolism of thyroid hormones is physiologically altered and can possibly even actively contribute to longevity. This should also be taken into consideration in the treatment of diseases of the thyroid and principally also for younger patients. For example, with progressing age comorbidities become more prevalent and especially in cardiovascular diseases, hyperthyroidism is less well tolerated, and should be treated more aggressively. Benign multinodular goiter also becomes more prevalent in old age and should be surgically treated when causing mechanical symptoms. The treatment concept for malignant diseases should be adapted to the holistic situation of the patient but principally in the same manner as in younger patients. Old and very old patients also benefit from adequate, risk-adapted treatment of thyroid gland diseases so that appropriate diagnostics and clarification are meaningful, regardless of age.

[Current controversies in risk-adapted therapy in differentiated thyroid cancer: Is less (therapy) really more?] / Aktuelle Diskussion zur risikoadaptierten Therapie des differenzierten Schilddrüsenkarzinoms: Ist weniger (Therapie) wirklich mehr?

In recent years, there has been worldwide a significant (relative) increase in "small" thyroid cancer (pT1 = tumor size of ≤10 mm), which has now reached a plateau. This fact and the absence of prospective and randomized clinical trials are increasingly leading to a discussion of the so-called risk-adapted management of differentiated thyroid cancer. The available studies are partly incomplete, retrospective and difficult to compare. In addition, factors such as different iodine supply, cost-benefit considerations and regional differences in quality of surgical procedures influence the implementation of therapy concepts. Therefore, the therapy of the differentiated thyroid cancer is currently the subject of intensive discussion, especially in "low risk" situations. There is a worldwide trend to classify the risk of differentiated thyroid cancer in general lower than in the past and thus also to reduce the extent of the traditionally recommended therapy. The discussion is increasingly moving from the "one size fits all" towards personalized and thus risk-adapted therapy of the differentiated thyroid cancer.The main goal of this "paradigm shift" is to avoid an "overtreatment" which may be associated with permanent complications due to "unnecessary" surgical procedures and any negative effects of radioiodine ablation.This overview attempts to answer the following questions: When is a risk-adapted therapy for differentiated thyroid cancer justified? What are the consequences in differentiated thyroid cancer if no radioiodine therapy is performed?

Functional aspects of silent ureteral stones investigated with MAG-3 renal scintigraphy.

BACKGROUND: To investigate functional aspects of silent ureteral stones with special focus on obstruction and its relationship to renal anatomy. The present study is the first investigation of renal excretory function in patients with silent ureteral stones. METHODS: Patients with primarily asymptomatic ureteral stones underwent a mercapto-acetyltriglycine (MAG-3) renal scintigraphy prior to treatment, in addition to anatomic evaluation of renal units and serum creatinine levels. The primary outcome measure was the presence or absence of obstruction. Secondary outcome measures were kidney anatomy, grade of hydronephrosis, location of stones, stone size, and serum creatinine levels. RESULTS: During a ten-year period, 14 patients (median age 52.6 years; range 37.3 to 80.7 years) were included in the study. The relative frequency of primarily asymptomatic ureteral stones among all patients treated for ureteral stones in the study period was 0.7%. Eleven renal units showed some degree of hydronephrosis while 3 kidneys were not dilated. On the MAG-3 scan, 7 patients had an obstruction of the ureter, 5 had no obstruction, and 2 had dysfunction of the kidney. A statistically significant correlation was established between the grade of obstruction and stone size (p = 0.02). CONCLUSIONS: At the time of presentation, only 64.3% of the patients revealed an obstruction in the stone-bearing renal unit. The degree of hydronephrosis and renal function were very diverse in this subgroup of patients with ureteral stones. The onset of ureterolithiasis and the chronological sequence of obstruction remain unclear in patients who have never experienced symptoms due to their stones.

[GIST: Imaging diagnosis, staging, and response assessment]. / Bildgebende Diagnostik bei GIST.

Diagnosis of gastrointestinal stromal tumors (GIST), which are located in the stomach or colon, is a domain of endoscopy. For midgut GIST is contrast-enhanced multidetector-CT the standard imaging technique. With the development of enteroclysis - MDCT better distension of the small bowel can be achieved to find even small tumors in the bowel wall. For staging of GIST is contrast-enhanced MDCT of the abdomen (and chest) recommended, unless PET/CT is widely available. Contrast-enhanced MRI is used for local staging of rectal tumors and as a problem-solving tool in patients with equivocal lesions at CT of the liver. In chemotherapy-responders, metastases may undergo necrosis and liquefaction with shrinkage. Therefore the RECIST criteria have been found to be unreliable to assess tumor response. The modified CT response criteria of Choi et al. have been developed and validated for more accurate assessment of chemotherapy. If available, is FDG-PET/CT the modality of choice for the follow-up of GIST patients at risk of metastases.

Post-treatment imaging of liver tumours.

In the past few years, great improvements have been made to achieve local tumour control of primary liver malignancies and liver metastases. For hepatocellular carcinoma (HCC), transarterial chemoembolisation (TACE) and tumour ablation techniques, including percutaneous ethanol injection (PEI), radiofrequency ablation (RF), and laser-induced interstitial thermotherapy (LITT) have been developed. For colorectal liver metastases, surgery is still the standard technique in localised disease, although percutaneous RF ablation has gained considerable acceptance. In patients with widespread disease, chemotherapy with new drugs offers improved survival. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are the modalities of choice to evaluate treatment response. The present review demonstrates imaging findings of complete and incomplete tumour control after intervention as well as the imaging spectrum of complications. Imaging guidelines according to the World Health Organization and Response Evaluation Criteria In Solid Tumors (RECIST) for assessment of chemotherapy response are presented.

11C-acetate positron emission tomography imaging and image fusion with computed tomography and magnetic resonance imaging in patients with recurrent prostate cancer.

PURPOSE: To assess the clinical value of computed tomography (CT) and magnetic resonance imaging (MRI) image fusion with 11C-acetate (AC) positron emission tomography (PET) imaging for detection and exact location of clinically occult recurrences. PATIENTS AND METHODS: Fifty prostate cancer patients with elevated/increasing serum prostate-specific antigen levels after radical therapy underwent whole-body AC PET. Uptake was initially interpreted as normal, abnormal, or equivocal. In case of abnormal or equivocal uptake, additional conventional imaging techniques, such as CT, MRI, and bone scans, were performed. To precisely define the anatomic location of abnormal uptake and to improve characterization of equivocal lesions, a software-assisted image fusion (CT-PET, MRI-PET) was performed and evaluated as site-by-site analysis of 51 abnormal (n = 37) or equivocal (n = 14) sites of all 50 patients. In 17 patients, additional histopathologic evaluation was available. RESULTS: In five (10%), 13 (26%), and 32 (64%) of the 50 patients, AC PET studies demonstrated AC uptake judged as normal, equivocal, and abnormal, respectively. Image fusion changed characterization of equivocal lesions as normal in five (10%) of 51 sites and abnormal in nine (18%) of 51 sites. It precisely defined the anatomic location of abnormal uptake in 37 (73%) of 51 sites. AC PET findings did influence patient management in 14 (28%) of 50 patients. CONCLUSION: Retrospective fusion of AC PET and CT/MRI is feasible and seems to be essential for final diagnosis. This is particularly true in patients with AC uptake in the prostate region.

Imaging of advanced neuroendocrine tumors with (18)F-FDOPA PET.

UNLABELLED: Nuclear medicine plays an important role in the imaging of neuroendocrine tumors (NETs). Somatostatin receptor scintigraphy (SRS) with (111)In-labeled somatostatin receptor analogs is a standard procedure for the detection and staging of NET. Based on the ability of NETs to store biogenic amines, this study evaluated whether 6-(18)F-fluoro-L-DOPA ((18)F-FDOPA) is a suitable PET tracer for NETs. METHODS: Twenty-three patients with histologically verified NETs in advanced stages were consecutively enrolled in the study. All patients underwent PET with (18)F-FDOPA, CT, and SRS within 6 wk. In patients with discrepancies between nuclear medicine and radiologic methods, follow-up investigations were performed by CT, MRI, and ultrasound. (18)F-FDOPA PET with attenuation correction was done 30 and 90 min after injection from the neck to the upper legs. SRS was performed with (111)In-DOTA-D-Phe(1)-Tyr(3)-octreotide at 6 and 24 h. All images were read without knowledge of the results of the other modalities. In every patient, the following regions were evaluated separately: bones, mediastinum, lungs, liver, pancreas, and others, including the abdominal and supraclavicular lymph nodes, spleen, and soft- tissue lesions. The findings were confirmed by clinical examination. The nuclear medicine methods were compared against morphologic imaging, which was considered as gold standard. RESULTS: The most frequently involved organs or regions were the liver (prevalence, 70%) and bone (52%), followed by mediastinal foci (31%), the lungs (22%), and the pancreas (13%). Fifty-two percent of patients had various lymphatic lesions. (18)F-FDOPA was most accurate in detecting skeletal lesions (sensitivity, 100%; specificity, 91%) but was insufficient in the lung (sensitivity, 20%; specificity, 94%); SRS yielded its best results in the liver (sensitivity, 75%; specificity, 100%); however, it was less accurate than PET in all organs. In about 40%, initial CT failed to detect bone metastases shown by PET that were later on verified by radiologic follow-up. CONCLUSION: (18)F-FDOPA PET performs better than SRS in visualizing NETs and may even do better than CT for bone lesions. SRS is essential to establish the usefulness of therapy with somatostatin analogs, yet is less accurate than (18)F-FDOPA PET for staging.

111In-DOTA- dPhe1-Tyr3-octreotide, 111In-DOTA-lanreotide and 67Ga citrate scintigraphy for visualisation of extranodal marginal zone B-cell lymphoma of the MALT type: a comparative study.

Somatostatin receptor (SSTR) scintigraphy and gallium-67 citrate ((67)Ga) scintigraphy have been used for visualisation of Hodgkin's lymphoma and non-Hodgkin's lymphoma. However, experience with B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type is very limited. The aim of this study was to prospectively compare the (67)Ga scintigraphy results with those obtained by (111)In-DOTA- dPhe(1)-Tyr(3)-octreotide ((111)In-DOTA-TOCT) and (111)In-DOTA-lanreotide ((111)In-DOTA-LAN) scintigraphy in patients with proven MALT-type lymphoma. Comparative scintigraphic examinations using (67)Ga, (111)In-DOTA-TOCT and (111)In-DOTA-LAN were performed in 18 patients (11 female and 7 male, median age 64+/-15 years) with histologically verified MALT-type lymphomas of various origin. Planar and single-photon emission tomography imaging acquisitions were performed after injection of a mean dose of 185+/-26 MBq (67)Ga and 165+/-20 MBq (111)In-DOTA-TOCT or (111)In-DOTA-LAN. All scintigraphic results were correlated with other conventional examinations including gastroscopy, colonoscopy, endosonoscopy, ophthalmologic investigation, CT of the thorax and abdomen and bone marrow biopsy. This comparative study showed that (67)Ga scintigraphy found abnormalities in 10 of 16 patients (63%) and detected 18 of 31 clinically involved sites (58%), but was false positive in three patients. (111)In-DOTA-TOCT found abnormalities in 9 of 15 patients (60%) and detected 15 of 27 clinical lesions (56%); it was false positive in two patients. (111)In-DOTA-LAN scintigraphy showed abnormalities in 7 of 11 patients (64%) and found 12 of 22 clinical lesions (55%). False-positive (111)In-DOTA-LAN scan results were found in two patients. For supra-diaphragmatic lesions, (67)Ga scintigraphy detected 12 of 16 sites (75%). (111)In-DOTA-TOCT scintigraphy revealed 7 of 15 lesions (47%). (111)In-DOTA-LAN showed 6 of 12 positive sites (50%). For infra-diaphragmatic involvement, the sensitivities of (67)Ga, (111)In-DOTA-TOCT and (111)In-DOTA-LAN were 40%, 67% and 60%, respectively. It is concluded that MALT-type lymphoma can be visualised by (67)Ga, (111)In-DOTA-TOCT and (111)In-DOTA-LAN scintigraphy. Although there were no statistically significant differences in patient-related and site-related sensitivities when using (67)Ga compared with (111)In-DOTA-TOCT and (111)In-DOTA-LAN, the sensitivity of (67)Ga tended to be superior to that of (111)In-DOTA-TOCT and (111)In-DOTA-LAN for supra-diaphragmatic lesions but inferior for infra-diaphragmatic involvement. In selected cases, the combination of (67)Ga and (111)In-DOTA-LAN or (111)In-DOTA-TOCT may increase the diagnostic efficiency in patients with MALT-type lymphoma.

Impact of localization studies on feasibility of minimally invasive parathyroidectomy in an endemic goiter region.

BACKGROUND: A localized single-gland disease is the basis for minimally invasive parathyroidectomy (MIP) in primary hyperparathyroidism (PHPT). (99m)Tc sestamibi scanning (MIBI) and high-resolution Doppler ultrasonography (US) are well-established techniques used to localize enlarged parathyroid glands. Additionally, US enables physicians to diagnose subclinical thyroid abnormalities. The aim of this study was to optimize localization results, applying a combined interpretation of MIBI and US, and to analyze the influence of these results on the feasibility of MIP (endoscopic/video-assisted and open) in an endemic goiter region. STUDY DESIGN: One hundred fifty consecutive patients with sporadic PHPT were prospectively subjected to MIBI and US to localize parathyroid lesions and to review the morphology of the thyroid gland. Bilateral cervical exploration was performed in all patients. The feasibility of MIP was calculated retrospectively on the basis of surgical findings and biochemical outcomes at least 12 months postoperatively (normocalcemia in 148 of 150 patients [99%]). RESULTS: Forty-five percent of patients (67 of 148) would have been suitable for minimally invasive endoscopic or video-assisted parathyroid exploration. These procedures would have succeeded in 38% of patients (56 of 148). Sixty-four percent (94 of 148) would have been suitable for minimally invasive open parathyroidectomy, which would have succeeded in 55% (82 of 148 patients). CONCLUSIONS: Not all patients are suitable for MIP. A combined interpretation of MIBI and US results is helpful in planning targeted exploration. In an endemic goiter region minimally invasive open parathyroidectomy is applicable in significantly more patients than is endoscopic and video-assisted MIP.

[Diagnosis and therapy of diseases of the endocrine system: new trends in nuclear medicine]. / Nuklearmedizinische Diagnostik und Therapie endokriner Erkrankungen: neue Trends.

Diagnosis and therapy of endocrine disorders in nuclear medicine has been improved through the implementation of new techniques especially with positron emission tomography (PET). In modern concepts of parathyroid gland surgery an exact anatomic localisation of adenomas is necessary, which may be achieved with MIBI-Scintigraphy being the most sensitive method in primary hyperparathyroidism. The optimal access to localise adenomas is the investigation with combined SPECT/X-CT systems. The use of such systems for diagnosing neuroendocrine tumors of the gastrointestinal system may also be helpful. For neoplasms of the adrenal gland PET systems could be used to differentiate between benign and malignant entities or to detect primary tumours. In case of incidentalomas J131-Norcholesterol and MIGB-scintigraphy has been proven helpful. Indications for nuclear medicine studies to detect abnormalities of the hypothalamic-hypophyseal system are established rarely.

[Imaging of diseases of the thyroid gland in Austria]. / Bildgebende Diagnostik von Schilddrüsenerkrankungen in Osterreich.

Imaging techniques for first line investigation of diseases of the thyroid gland are sonography (US) and scintigraphy, followed in dedicated cases by magnetic resonance imaging (MRI). Malignant lesions are generally hypoechoic on US with calcifications visible in some cases. The appearance of lymph node metastases is similar to that of the primary tumour. The various forms of goiter are the most commonly occurring forms of thyroid diseases in Austria, they appear heterogenous with hyperechoic as well as hypoechoic or anechoic nodes, in some cases with calcification. US findings of thyreoiditis are in acute forms of the disease more hypoechoic with diffuse swelling and hyperechoic with scar formations in chronic forms. Ectopic thyroid tissue occurs often in the form of thyroglossal duct cysts which are anechoic or hypoechoic.

[Hybrid imaging for endocrine diseases: new perspectives]. / Hybrid Imaging bei endokrinen Erkrankungen: neue Perspektiven.

Hybrid Imaging, also termed dual modality imaging, is the technique of fusionizing and interpreting images, that are gained from two different modalities constructed in one unit. Therefore, hybrid imaging may be regarded as a form of image fusion. Clinical applications in the field of endocrinology are the localization of neuroendocrine tumors and of lesions of the adrenal or the parathyroid glands. Significant diagnostic impact can be gained with this technique influencing the certainty of radiological reports.

Mortality of patients with pulmonary embolism.

BACKGROUND: Pulmonary embolism (PE) is a potentially fatal disorder with highly varying mortality rates. To provide information that is more precise for prospective intervention studies, we analysed the data of our patients with PE, defining clinically relevant subgroups with respect to their individual mortality rates. METHODS: We studied 283 consecutive patients with confirmed PE diagnosis, with respect to demographic data, risk factors for thromboembolic disease and clinical signs. In addition, diagnostic and therapeutic interventions such as blood gas analysis (BGA), lactate and D-dimer determination, electrocardiography (ECG), echocardiography, spiral computer tomography (Spiral CT), ventilation/perfusion lung scintigraphy (V/Q-Scan), thrombolytic therapy, mechanical ventilation, and cardiopulmonary resuscitation (CPR), were accounted for. Study endpoint was mortality rates on day three. RESULTS: Overall, mortality rate was 15% (42 of 283). Mortality rates differed considerably; 95% of patients with cardiac arrest on arrival (21 of 22), 85% of patients with cardiac arrest--not in hospital (28 of 33), 80% of patients receiving mechanical ventilation (40 of 50), 77% of patients needing cardiopulmonary resuscitation within the first 24 hours (37 of 48), 37% of patients with syncope (18 of 49), 30% of patients receiving thrombolytic treatment (25 of 87), 26% of patients on whom lactate measurement was performed (36 of 139), 18% of patients on whom blood gas analysis was done (35 of 197), 17% of patients on whom echocardiography was performed (34 of 195), 8% of patients with twelve complete lead ECG recordings (21 of 262) and D-Dimer determination (12 of 148), 2% of patients tested on Spiral CT (5 of 226) and 1% where a V/Q-Scan was performed (1 of 74). CONCLUSION: Patients with PE who received mechanical ventilation, cardiopulmonary resuscitation, and thrombolytic treatment had very high mortality rates of 80, 77 and 30% respectively. However, patients stable enough for diagnostic procedures as Spiral CTs and V/Q-Scans had mortality rates of 1 to 2%. These facts are to be considered when planning pulmonary embolism intervention trials in which reduction of mortality is a defined endpoint.

Atypical focal nodular hyperplasia of the liver: imaging features of nonspecific and liver-specific MR contrast agents.

OBJECTIVE: The objective of our study was to describe the functional and differential uptake features of atypical focal nodular hyperplasia using different MR contrast agents and to evaluate their potential role in the diagnosis and characterization of focal nodular hyperplasia. MATERIALS AND METHODS: Contrast-enhanced MR images of 45 patients with 85 focal nodular hyperplasia lesions were retrospectively reviewed. In these patients, sonographic findings were nonspecific (n = 37), or CT features were inconclusive (n = 8). Non-liver specific gadolinium chelates were used in 18 patients (48 lesions) suspected of having either focal nodular hyperplasia or hemangioma. The following liver-specific agents were used in patients with suspected focal nodular hyperplasia or metastases: mangafodipir trisodium, 30 patients (55 lesions); ferumoxides, six patients (16 lesions); and SHU 555 A, six patients (six lesions). Individual lesions were quantified by signal intensity and assessed qualitatively by homogeneity, contrast enhancement, and presence of a central scar. RESULTS: At unenhanced MR imaging, the triad of homogeneity, isointensity, and central scar was found in 22% of the focal nodular hyperplasia lesions. On mangafodipir trisodium-enhanced T1-weighted images, all focal nodular hyperplasia lesions showed contrast uptake: in 64% of the lesions, uptake was equal to parenchyma; 25%, greater than the parenchyma; and 11%, less than the parenchyma. On iron oxide-enhanced T2-weighted images, all focal nodular hyperplasia lesions showed uptake of the contrast agent, but contrast uptake in the lesions was less than in the surrounding parenchyma. Dynamic gadolinium chelate-enhanced MR imaging showed early and vigorous enhancement of focal nodular hyperplasia lesions with rapid washout in 88%. Atypical imaging features of the lesions included hyperintensity on T1-weighted images, necrosis and hemorrhage, and inhomogeneous or only minimal contrast uptake. CONCLUSION: For patients in whom the diagnosis of focal nodular hyperplasia cannot be established on unenhanced or gadolinium-enhanced MR imaging, homogeneous uptake of liver-specific contrast agent with better delineation of central scar may help to make a confident diagnosis of focal nodular hyperplasia.

'Suppressed' double adenoma--a rare pitfall in minimally invasive parathyroidectomy.

Since the introduction of a quick intraoperative parathyroid hormone (QPTH) assay, complete removal of hyperfunctioning parathyroid tissue can be proven during surgery. We report on a scintigraphically and biochemically documented patient with persistent primary hyperparathyroidism (PHPT) caused by suppressed hyperfunctioning parathyroid tissue. A left lower enlarged parathyroid gland was resected by minimally invasive open parathyroidectomy. QPTH measurements confirmed complete resection of hyperfunctioning tissue and histology showed a tumorous enlarged left lower parathyroid gland. The patient was normocalcemic until 1 month after surgery, when serum calcium increased again. A MIBI scan 6 months after surgery showed no evidence of hyperfunctioning parathyroid tissue. After an increase of PTH, a third MIBI scan another 3 months later was performed. Increased tracer uptake behind the lower pole of the right thyroid lobe was seen and confirmed by ultrasonography. Another tumorous enlarged parathyroid gland was removed. These findings support the hypothesis that smaller yet abnormal parathyroid glands can be suppressed and may become hypersecretory if left in situ after surgical removal of the larger gland.

Scintigraphic imaging of the adrenal glands.

This article presents the well established scintigraphic imaging techniques of the adrenal glands. Both adrenocortical scintigraphy with [131]6beta-iodomethylnorcholesterol (NP-59) and adrenomedullary imaging with 131I or 123I-labelled metaiodobenzylguanidine (MIBG) as function-dependant imaging techniques provide functional metabolic information for lesion characterization. They enable the distinction between unilateral and bilateral adrenal lesions. Furthermore, they have the advantage of giving the possibility of a whole body evaluation with a single administration of the tracer without additional radiation dose. On the other hand, radiological imaging modalities provide excellent anatomical details which is essential for planning therapy. Both radiological and scintigraphic imaging methods of the adrenal glands are necessary and should, therefore, be considered complementary.