European journal of nuclear medicine
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Somatostatin (SMS) scintigraphy is widely used for the detection and staging of neuroendocrine tumours. Because of its superior imaging properties, there is growing interest in the use of positron emission tomography (PET) technology for SMS scintigraphy. This study addressed the production of gallium-68 DOTATOC, its biokinetics and its clinical performance in detecting SMS-positive tumours and metastases. ⋯ Tumour to non-tumour ratios ranged from >3:1 for liver ((111)In-octreotide: 1.5:1) to 100:1 for CNS ((111)In-octreotide: 10:1). With (68)Ga-DOTATOC >30% additional lesions were detected. It is concluded that PET using (68)Ga-DOTATOC results in high tumour to non-tumour contrast and low kidney accumulation and yields higher detection rates as compared with (111)In-octreotide scintigraphy.
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Wilson's disease (WD) is a copper deposition disorder which can result in a number of extrapyramidal motoric symptoms such as parkinsonism. Therefore, this study was carried out to investigate, for the first time, nigrostriatal dopaminergic function in WD in relation to different courses and severity of the disease. Using high-resolution single-photon emission tomography (SPET) after administration of 2ss-carbomethoxy-3ss-(4[123I]iodophenyl)tropane ([123I]ss-CIT), striatal dopamine transporters (DAT) were imaged in 43 WD patients and a control group of ten subjects. ⋯ For degree of liver alteration, significant correlations were obtained with the putaminal binding ratio (r=-0.37) and the CA/PU ratio (r=0.44). From these results is concluded that in WD the nigrostriatal dopaminergic function is compromised to varying extents. The degree of this presynaptic alteration of dopaminergic neurotransmission depends on the clinical course and severity of this copper deposition brain disorder and also varies in the different striatal substructures.
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A modern approach to the surgical treatment of early breast carcinoma requires intraoperative localisation of non-palpable lesions and assessment of the lymph node status. Localisation of breast lesions can be achieved by intratumoural injection of a small amount of radiotracer and intraoperative use of a gamma probe (i.e. radioguided occult lesion localisation, or ROLL). Assessment of the lymph node status is possible by means of the sentinel node approach. ⋯ Histological examination of the nodes showed metastases in 20 cases: in 15 cases there were micrometastases, and in five, macrometastases. In conclusion, this study has demonstrated the feasibility of the proposed procedure. Simultaneous performance of ROLL and sentinel node localisation using a single tracer represents a useful and practicable choice in the management of early breast cancer.
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Comparative Study
Brain tumour imaging with carbon-11 choline: comparison with FDG PET and gadolinium-enhanced MR imaging.
The purpose of this study was to assess the clinical potential of methyl-11C-choline (11C-choline) in the diagnosis of brain tumours. To this end, the results of 11C-choline positron emission tomography (PET) in 22 patients suspected of having brain tumours were compared with the findings of contrast-enhanced magnetic resonance (MR) imaging and fluorine-18 fluorodeoxyglucose PET. A histopathological diagnosis was made for each patient during open surgery. ⋯ This difference was statistically significant (mean+/-SD: 8.7+/-6.2, n=9 versus 1.5+/-0.7, n=5, P<0.03) when data pertaining to the prominent uptake of 11C-choline in a patient with a pilocytic astrocytoma were excluded. 11C-choline PET failed to detect non-neoplastic lesions in two patients. Areas of 11C-choline accumulation in PET scans were larger than areas enhanced on MR images in five cases involving high-grade gliomas. 11C-choline PET differentiated between low-grade gliomas and high-grade gliomas, but did not differentiate between low-grade gliomas and non-neoplastic lesions. The combination of 11C-choline PET and MR imaging may provide investigators with an accurate means by which to identify high-grade gliomas.
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Comparative Study
Schwannoma of the extremities: the role of PET in preoperative planning.
The aim of this study was to determine the relative utility of various preoperative diagnostic imaging modalities for the evaluation of benign schwannoma, including positron emission tomography (PET) utilising fluorine-18 fluoro-2-deoxy-D-glucose (FDG) and fluorine- 18 alpha-methyl tyrosine (FMT). computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). We retrospectively reviewed imaging findings in 22 patients with 25 histopathologically documented benign schwannomas of the extremities. Pre-operative imaging included: FDG-PET (n=22), FMT-PET (n=17), MRI (n=25), CT (n=16) and DSA (n=17). ⋯ All tumours but one were treated by surgical enucleation. One tumour suspected to be malignant on the basis of imaging findings was treated with primary wide resection. Although CT, MRI and PET studies are all useful for the detection and localisation of schwannoma, our findings suggest that, among the imaging modalities studied, FMT-PET may be the most reliable technique for the differentiation of benign schwannoma from malignancy.