Diagnostic value of MIBG cardiac scintigraphy for differential dementia diagnosis.

OBJECTIVE: Iodine-123 metaiodobenzylguanidine (MIBG) cardiac scintigraphy has shown the potential to discriminate dementia with Lewy bodies (DLB) from Alzheimer's disease (AD). However, these studies did not reflect clinical practice, as patients with ischemic heart disease, heart failure, diabetes mellitus, arterial hypertension, and hyperlipidemia and patients treated with antidepressants like trazodone were excluded. METHODS: This study aimed to evaluate the use of MIBG cardiac scintigraphy to diagnose DLB in clinical practice. Moreover, the potential diagnostic value of MIBG cardiac scintigraphy in patients with clinically ambiguous dementia diagnosis (DLB versus AD) was tested. Eighty-five patients with a possible clinical diagnosis of DLB entered the study. MIBG uptake was determined by calculating the heart-to-mediastinum-uptake ratio (H/M). RESULTS: The average H/M ratio was 1.42 ± 0.35. The number of core features for DLB and the H/M ratio were negatively correlated (p = 0.001; r = -0.360). With an H/M ratio cutoff of 1.68 in 20 patients with clinically ambiguous dementia diagnoses (DLB versus AD) at the moment of MIBG cardiac scintigraphy, 95% (19/20) of the patients were correctly classified as compared with clinical or definite diagnosis at follow-up, with sensitivity and specificity values for diagnosing DLB of 100% (16/16) and 75% (3/4), respectively. The H/M ratio was influenced only by age (p = 0.046; r = -0.217) and gender (p = 0.024) and not by any other variable studied. CONCLUSIONS: The MIBG cardiac scintigraphy H/M ratio is a possible diagnostic biomarker for DLB in routine clinical practice and might have an added diagnostic value in case of doubt between DLB and AD.

High-dose lanreotide in the treatment of poorly differentiated pancreatic neuroendocrine carcinoma: a case report.

Pancreatic neuroendocrine tumors (NETs), including poorly differentiated carcinomas (NECs), are rarely encountered. The majority of these tumors do not secrete excess hormones, but functioning NETs produce large amounts of vasoactive peptides and may cause carcinoid syndrome. Synthetic somatostatin analogs (SSAs) have been widely used in NETs for control of hormonal syndromes. Here, we present a case of poorly differentiated, grade 3 pancreatic NEC associated with carcinoid syndrome, for which adequate symptom control was achieved for 2 years and 4 months using the long-acting SSA lanreotide Autogel(®). In February 2009, a 55-year-old woman presented with episodes of flushing, diarrhea and epigastric pain. Imaging techniques revealed the presence of a metabolically active mass expressing somatostatin receptors in the hilar area of the liver. Histopathological examination confirmed the malignant nature of the mass, which was identified as a poorly differentiated grade 3 pancreatic NEC (TNM staging: T4NxM0). Therapeutic options were limited for the patient because of the extent of the primary mass involving the celiac axis, severe gastrointestinal toxicity experienced as a side effect of chemotherapy with cisplatin-etoposide and, later in the course of the disease, extensive liver metastases and carcinoid heart syndrome. Along with a palliative debulking surgery and right portal vein embolization, biotherapy with a high dose of lanreotide Autogel (120 mg/14 days) contributed to alleviation of symptoms caused by hormone overproduction, even after the development of liver metastases. These results suggest that patients with poorly differentiated NECs who exhibit signs of carcinoid syndrome can benefit from treatment with somatostatin analogs.

The value of (18)FDG-PET for the detection of infected hip prosthesis.

We compared the accuracy of fluorine-18 labelled 2-fluoro-2-deoxy- d-glucose positron emission tomography ((18)FDG PET) with that of technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy (LS) in the detection of infected hip prosthesis. Seventeen patients with a hip prosthesis suspected for infection were prospectively included and underwent (99m)Tc-methylene diphosphonate bone scintigraphy (BS), LS and an (18)FDG-PET scan within a 2-week period. Seven volunteers with ten asymptomatic hip prostheses were used as a control group and underwent BS and an (18)FDG-PET scan. Bacteriology of samples obtained by surgery or by needle aspiration and/or clinical follow-up for up to 6 months were used as the gold standard. Planar images of BS and LS (4 and 24 h p.i.) were acquired, followed by single-photon emission tomography (SPET) LS images (after 4 h). These images were scored as positive or negative by two experienced readers. The (18)FDG-PET scans of the patients were compared with the tracer distribution pattern in the asymptomatic control group and with BS. A phantom study was performed in order to identify artefacts. For this purpose, three different attenuation correction methods were tested. The combined analysis of the planar BS and LS resulted in a 75% sensitivity and a 78% specificity. The SPET LS images showed a better lesion contrast, resulting in an 88% sensitivity and a 100% specificity, while 24-h planar images were of no additional value. The analysis of PET images alone resulted in an 88% sensitivity and a 78% specificity. The combination of (18)FDG-PET and BS images resulted in an 88% sensitivity and a 67% specificity. Given the presence of small errors near the edge of the metal, which can induce significant artefacts in the corrected emission image, we decided to use the data without attenuation correction. In this preliminary study, (18)FDG-PET scans alone showed the same sensitivity as combined BS and LS, although the specificity was slightly lower.