Klaus Joseph

Clinical Value of Parathyroid Scintigraphy with Technetium-99m Methoxyisobutylisonitrile: Discrepancies in Clinical Data and a Systematic Metaanalysis of the Literature

There is a considerable discrepancy in the literature concerning the sensitivity of parathyroid scintigraphy (PS) with 99mTc-MIBI. We therefore analyzed our own data and compared them to the literature in a metaanalysis. All patients who received 99mTc -MIBI scintigraphy and subsequent surgery in our department for the detection of enlarged parathyroid glands in primary (pHPT) or secondary (sHPT) hyperparathyroidism between 1991 and 1999 were included in our retrospective analysis. The results of surgery served as the gold standard. For a true positive result, the scintigraphy had to predict the exact location of parathyroid adenoma (PA) or parathyroid hyperplasia (PH). We then compared these data to the results of a nonstatistical systematic metaanalysis of the literature. Patients (178) underwent PS between 1991 and 1999; 139 were operated on and included in this study. Of these, 109 had pHPT and 30 had sHPT. The sensitivity and specificity of the PS were found to be 45% / 94% for pHPT and 39% / 40% for sHPT. Fifty-two studies concerning PS were included in the metaanalysis. Sensitivities reported varied from 39% to > 90%. Consideration of the different possible techniques used for PS could not explain these discrepancies. Our data show that the sensitivity of PS in clinical routine may be lower than expected from the literature. Our data are consistent with other studies and with partially unpublished clinical observations from other university hospitals. We believe that a well-designed and properly conducted prospective study is necessary to evaluate the reasons for the differences observed.

The role of bone scintigraphy in patients with Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare disorder that has been reported fewer than 60 times in the literature. Although clinical findings seem to be specific at first sight, histologic classification remains unclear. It has not been decided whether ECD is part of the spectrum of histiocytoses or whether it may be a lipid storage disorder or even a primary macrophage cell disorder, although it does show a distinct histologic pattern. However, the clinical appearance alone shows several typical features, rendering the diagnosis very probable if present. This article illustrates the importance of bone scanning in ECD, because the scintigraphic pattern of involved skeletal sites may in themselves lead to the diagnosis. Several differential diagnoses are considered. The importance of bone scintigraphy as an imaging method in patients with an unclear diagnosis is discussed, as exemplary in ECD, as is its role for the detection of sites of skeletal involvement in other diseases.

Preoperative localization of gastrointestinal endocrine tumors using somatostatin-receptor scintigraphy

OBJECTIVE The purpose of this study was to determine the value of somatostatin-receptor scintigraphy (SRS) in the preoperative localization of gastrointestinal endocrine tumors. The authors report their preliminary experiences with this new technique as compared to conventional imaging studies like computed tomography (CT) and ultrasonography (US). SUMMARY BACKGROUND DATA Most endocrine tumors possess high-affinity somatostatin-receptors. Using the stable, 111Indium labelled somatostatin analogue pentatreotid, which binds to these receptors, it is possible to detect somatostatin-receptor-positive tumors scintigraphically. METHODS In nine patients with various gastrointestinal endocrine tumors, SRS, CT, and US were performed before surgical exploration. The preoperative imaging studies and intraoperative ultrasound (IOUS) were then compared to findings on surgical exploration. RESULTS Twelve primary tumors were found in 8 patients at surgical exploration. These primary tumors were correctly identified with SRS in five patients, with US in four patients, and with CT in three patients. In one patient with the Zollinger-Ellison syndrome, scintigraphy suggested a tumor in the area of the hepatoduodenal ligament, while CT and US had negative results. The underlying gastrinoma could not be identified despite extensive surgical exploration. Scintigraphy, CT, and US showed comparable results in the detection of metastases in four patients. CONCLUSIONS The data from this small series suggest that SRS is helpful in the preoperative localization of gastrointestinal endocrine tumors.

Influence of somatostatin receptor scintigraphy and CT/MRI on the clinical management of patients with gastrointestinal neuroendocrine tumors: an analysis in 188 patients.

Aim: Many studies describe the sensitivities and specificities of computed tomography (CT), magnetic resonance imaging (MRI), and somatostatin receptor scintigraphy (SRS) in patients with gastrointestinal neuroendocrine tumors (GNT). We performed a study to evaluate the influence of these techniques on the therapeutic management of patients with advanced stages of GNT. Patients and Methods: The results of either CT/MRI scans or SRS were reviewed by two independent observers who decided on the therapy of a patient. They then had to determine whether the results of the complementary imaging modality would change the decision. The study design was a matched cross-over study with two groups matching in respect to tumor type, imaging modality known first to the observer, and number of patients. For further analysis, patients were divided into three subgroups dependent on tumor stage (group 1, without metastases, group 2, liver metastases, group 3, recurrent disease/extrahepatic metastases). Results: 188 patients were included into the study. If SRS was known to the observers first, CT/MRI changed the therapeutic management in 16.2, 13.9 and 11.4% of the patients (subgroups 1–3). SRS changed the therapeutic management in 13.5, 12.5 and 10.3%. Overall, CT/MRI would have changed the management in 13.3% and SRS in 11.7% of the patients. Conclusion: Though the patients studied mainly suffered from already advanced stages of the disease, all imaging techniques change the therapeutic management to a comparable extent. Our results support the importance of combined imaging in the management of patients with GNT.

Assessment of ventricular function with first-pass radionuclide angiography using technetium 99m hexakis-2-methoxyisobutylisonitrile: a European multicentre study.

In the context of a multicentre study on the use of technetium 99m hexakis-2-methoxyisobutylisonitrile (99mTc-Sestamibi), we evaluated the accuracy of the ventricular function assessed at rest by means of first-pass radionuclide angiocardiography acquired during the injection of the tracer for myocardial perfusion scintigraphy. The results were compared with first-pass studies performed using reference tracers sodium pertechnetate Tc 99m or technetium 99m diethylene triamine penta-acetic acid or with gated radionuclide angiocardiography. A total of 66 patients of the 105 enrolled in the study could be evaluated. The comparison of the first-pass studies was possible in 33 subjects with regard to the left ventricular ejection fraction, yieldingr=0.909 (P< 10−6), and in 22 cases with regard to the right ventricular ejection fraction, yieldingr=0.712 (P<0.001). The comparison between the first-pass study using99mTc-Sestamibi and the equilibrium gated radionuclide angiocardiography was possible for the left ventricular ejection fraction in 26 cases, withr=0.937 (P<10−6), and for the right ventricular ejection fraction in 15 subjects, withr=0.783 (P<0.001). In conclusion, the assessment of ventricular function performed by acquiring a first-pass radionuclide angiocardiograph during the injection of99mTc-Sestamibi for perfusion myocardial scintigraphy can be considered reliable and accurate, when compared with the usually employed techniques. This result confirms the feasibility of a combined evaluation of perfusion and function at rest and during stress testing, which represents one of the most interesting advantages offered by the use of99mTc-Sestamibi.

Venous bypass after deep venous thrombosis visible on an early-phase bone scan.

Bone scintigraphy was performed on a 66-year-old woman because of pain in the left hip 5 years after prosthetic replacement of the joint. Loosening of the prosthesis was suspected. Changes secondary to a prior deep vein thrombosis and superficial vein prominence were seen.

Persistent segmental perfusion defect in an intermediate-probability lung scan

A perfusion defect persisting for 11 years in a 37-year-old woman is described. This area demonstrated a V/Q mismatch but was not caused by pulmonary embolism.

Huge necrotic liver metastases in advanced pancreatic carcinoma visualized on bone scans.

A 49-year-old man had a histologically confirmed pancreatic carcinoma with several huge necrotic metastases in the liver. Many cases of increased radionuclide uptake in liver metastases have been reported, but in this case the radionuclide uptake was missing.

Imaging of Parathyroid Adenomas Using Technetium-99m-Sestamibi in an Endemic Goiter Area

Double-phase single radionuclide parathyroid scintigraphy with Tc-99m-Sestamibi was performed in 26 patients with primary and in 9 patients with secondary hyperparathyroidism. The Tc-99m-Sestamibi-scan identified and localized 21 of 26 adenomas in the 26 patients with pHPT. In only 6 of the 9 patients with parathyroid hyperplasia a focally increased uptake was found. The cause of one false positive result in 5 control patients was an increased Tc-99m-Sestamibi-uptake in a follicular adenoma of the thyroid gland. Parathyroid scintigraphy using Tc-99m-Sestamibi as a single radiotracer is at least as sensitive in detecting and localizing parathyroid adenomas as TI/Tc-scintigraphy.