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Biomedical subjects

L Troncone

Publications and source records attributed to L Troncone.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

Diagnostic imaging of euthyroid goiter.

In diffuse or nodular euthyroid goiter, diagnostic imaging is indicated to define, by sonography, the morphology, size and structure of the goiter and to evaluate, by scintigraphy, the regional thyroid function. The instrumental diagnosis of thyroid nodule is essentially based on sonography, scintigraphy and (US-guided) needle aspiration cytology. The evaluation of some sonographic findings (echogenicity, calcification, lesion margins and presence of peripheral ring) may direct to the differentiation of a benign or malignant lesion. The role of color Doppler in the characterization of thyroid nodules is still controversial. Scintigraphy provides information on nodular function, being also the only exam able to show the presence of autonomously functioning thyroid tissue ("hot" nodule), whose diagnosis allows to rule out the presence of thyroid carcinoma with a very strong probability. In intrathoracic goiter, CT and MRI and indicated to show the continuity with the cervical thyroid and to define the relationships with adjacent structures. Radioiodine scintigraphy shows with high (> 90%) diagnostic accuracy the thyroid nature of a mediastinal mass (plunging goiter).

Diagnostic Imaging↗
PubMedDate not supplied

Role of nuclear medicine in the diagnosis and therapy of medullary thyroid carcinoma.

Medullary thyroid carcinoma (MTC) originates in the parafollicular cells (C cells) of the thyroid, secreting both calcitonin and CEA. Genetic and biochemical testing allow early pre-clinical identification of familial forms. Sporadic MTC usually presents as a solitary palpable thyroid nodule and in most cases the definitive diagnosis is established only at the time of surgery. Nuclear medicine procedures, which play a minor role in the preoperative evaluation of MTC, are essential in postoperative follow-up to detect residual and/or recurrent tumor. A number of radiopharmaceuticals are able to visualize MTC lesions with considerable advantages in diagnosis and prognosis, some of them having also a therapeutic role. Among them, 99mTc[V]DMSA shows the highest diagnostic sensitivity and is considered by many authors the radiopharmaceutical of choice in the postoperative work-up of MTC. Radioiodinated MIBG, in spite of its high specificity has a poor sensitivity (30%); however it is useful for the identification of pheochromocytoma and, in patients showing MIBG uptake in tumoral lesions, high activities of 131I-MIBG may be used for therapy. 111In labeled octreotide detects lesions which express somatostatin receptors; a positive scintigraphic result seems to give also prognostic information (higher uptake in slow-growing lesions) and provides the basis for treatment with octreotide or lanreotide and 111In or 90Y-labeled octreotide analogues. Interesting perspectives are offered by 18F-FDG PET and monoclonal anti-CEA labeled antibodies; the latter may be also used for therapy.

Carcinoma↗
PubMedDate not supplied

Biology of metaiodobenzylguanidine interactions with human neuroblastoma cells.

[131I]Metaiodobenzylguanidine (131I-MIBG) is selectively taken up and stored by tumors derived from the neural crest and is utilized in the diagnosis and treatment of neuroblastoma (NB). Variable MIBG uptake has been observed, although the underlying mechanisms are not known. We have studied the uptake kinetics of 125I-MIBG and uptake characteristics of NB cell clones with different phenotypes (SH-SY5Y and SH-EP1, the neuroblastic and the substrate-adherent sublines of SK-N-SH respectively, BE(2)-M17 and LA-N-1n with neuroblastic phenotype). We have been able to correlate the MIBG uptake with the neuroblastic phenotype: a specific uptake system satisfying all the characteristics of the neuronal uptake-1 (temperature dependency, sodium dependency, high affinity, saturability and imipramine sensitivity) was observed in all the neuroblastic sublines. In contrast, MIBG accumulation was a passive diffusion phenomenon in the substrate-adherent clone SH-EP1. In addition, terminal neuronal differentiation induced in SH-SY5Y by retinoic acid caused a marked increase of the uptake and retention of MIBG. Our findings may be pertinent to an understanding of the variability of the MIBG uptake in vivo.

3-Iodobenzylguanidine↗