Nuclear Medicine Review 2008, tom 11, nr 2

BACKGROUND: [61Cu]Thiophene-2-aldehyde thiosemicarbazone ([61Cu]TATS) (4) was prepared according to an analogy of carrier copper compound with antitumor activity, for eventual use in PET.

MATERIAL AND METHODS: [61Cu]TATS was prepared using copper-61 acetate and in-house made ligand (TATS) in one step. 61Cu was produced via the natZn(p,x)61Cu nuclear reaction (180 µA, 22 MeV, 3.2 h) followed by a two-step  chromatography method (222 GBq of 61Cu2+). [61Cu]TATS preparation was optimized for reaction conditions (buffer concentration and temperature). The tracer was finally administered to normal rats for biodistribution studies.

RESULTS: Total radiolabelling of the tracer took 30 minutes with a radiochemical purity of more than 90% (using HPLC and RTLC) and specific activity of about 250–300 Ci/mmol. The complex was stable in the presence of human serum for an hour. The biodistribution of copper cation and the tracer was checked in wild-type rats for up to 2 hours with significant spleen and lung uptake of the tracer.

CONCLUSIONS: The production of 61Cu via the natZn(p,x)61Cu is an efficient and reproducible method with high specific activity leading to the production and preliminary evaluation of [61Cu]TATS, a potential PET tracer, was reported.

BACKGROUND:Numerous reports indicate that some iodinated compounds of benzamide derivatives display a strong affinity to the cells of melanoma. In the present report, a compound [N-(2-diethylaminoethyl)-3-iodo-4metyoxybenzamide (131I-IMBA)] has been prepared by two different labelling methods. Biodistribution of the injected compound was followed in mice with experimentally induced B16 melanoma tumours, and tumour/tissue ratios were studied as a function of time post administration.

MATERIAL AND METHODS: The iodinated 131I-IMBA was obtained by means of 131I exchange for nonradioactive iodine atoms (method I) and by means of 131I substitution for a metalorganic group (method II). The last preparation was purified by chloroform extraction. The chemical purity was assessed by means of ascending thin layer chromatography (TLC). The biodistribution of 131I-IMBA in C57 Black mice was studied in animals with experimentally induced B16 mice melanoma tumours.

RESULTS: The mean labelling efficiency exceeded 95 and 80 % for methods I and II, respectively, at radiochemical purity > 95% in both cases. 131I-IMBA was vividly cumulated by melanoma tumours in mice. At 24-hours post 131I-IMBA administration the values of tumour/non-tumour ratios for the compound labelled by method II reached the following values: tumour/liver 10 ± 3, tumour/lung 15 ± 12, tumour/blood 153 ± 39, tumour/intestines 176 ± 26, tumour/kidneys 270 ± 107, and tumour/muscle 448 ± 82. These values exceeded, by an order of magnitude, the corresponding ratios for the same compound labelled by method I.

CONCLUSIONS: High values of tumour/non-tumour ratios indicate that 131I-IMBA could be a promising radiopharmaceuticalfor clinical diagnosis (staging) of melanomas in humans.

Differential diagnostics of extrapyramidal diseases remains an important challenge for clinicians. Many conditions mimic  Parkinsonian syndromes, making diagnosis difficult, particularly during the early clinical stages when the signs and symptoms are subtle. Functional investigations of the dopaminergic system with the use of nuclear medicine methods create a new possibility of differentiation between the involvement of the pre- and postsynaptic parts of the system [1, 2]...

The absorption of gamma rays by a patient’s body significantly affects scintigraphic images. This phenomenon is particularlyimportant in the case of myocardial perfusion images. In such studies, a smaller fraction of radiation emitted from parts of the myocardium located deeper in the body (e.g. the inferior wall) reaches the gamma camera detectors than the fraction of quanta emitted from parts of the myocardium located at a lesser depth, such as an apex...

Bone scintigraphy is frequently performed to investigative many skeletal abnormalities (such as primary tumoural and  metastatic involvement of the skeleton, infections of the bone and soft tissue, fractures and other traumatic lesions of the skeleton, etc.) in daily nuclear medicine practice. Interpretation of a skeletal scintigraphic study requires not only images of high quality, but careful scrutiny, bearing in mind the normal variants and evaluation in light of the particular clinical problem [1]...

Breast carcinoma is a serious health problem for women, with a strong socioeconomic impact [1]. Early diagnosis is achieved by routine physical examination and programmed screening with mammography. Both procedures are known to have certain diagnostic limitations [2]...

We report the case of a 59-year-old woman who presented in our centre for 18F-fluorine-dexy-glucose (18F-FDG) PET/CT scandue to a defect of the peripheral motor neuron. The patient had a history of squamous cell carcinoma of the uterine cervix, diagnosed 2 years previously and treated with brachytherapy...