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Technical advances in computed tomography (CT), including helical CT and multidetector CT, have resulted in an improved ability to evaluate the small intestine. CT examination of the small bowel requires the use of dedicated techniques for optimal evaluation of inflammatory bowel disease in order to select the most appropriate therapeutic strategy for the individual patient and to monitor disease progression over time.Although intraluminal contrast media combined with intravenous iodinated contrast agents with a biphasic injection protocol provide good visualization of the typical lesions of the disease, accurate estimation of the degree of disease activity can only be achieved with nuclear imaging. Owing to continuous technical improvements, magnetic resonance imaging is expected to play an increasing role in the near future. However, in selected patients, three-dimensional endoanal ultrasonography remains the gold standard technique for assessing the anal sphincter and the recto-anal junction.

After esophagectomy, the stomach is usually used to restore digestive continuity. To prevent postoperative delayed gastric emptying, most authors perform a gastric drainage procedure or transpose a tubulized stomach. The aim of our work is to evaluate the emptying of a transposed whole stomach without performing a pyloromyotomy or a pyloroplasty. From 1996 to January 2004, 45 patients underwent total esophagectomy for cancer or for caustic stenosis. Reconstruction of digestive continuity was realized through transposition of the whole stomach without performing a pyloric drainage procedure. At 12 months after the intervention, 35 patients (77.8%; 20 men and 15 women), with a mean age of 63.4 years, were submitted to a gastric emptying scintigraphic study by means of ingestion of a mixed meal labeled with 37 MBq 99mTc-sulfur colloid. Imaging of the gastric contents was acquired immediately before and after for 240 minutes at 10-minute intervals. The half-emptying time was defined as the time to emptying of 50% of the gastric content measured at time 0. A control group included 20 patients who underwent total esophagectomy with transposition of a tubulized stomach and cervical anastomosis. Mean half-emptying time was 71.4 minutes (range, 15–90 minutes; control group, 68.7 minutes; reference range, 83 * 34 minutes): all the patients were in the normal range except one with a half-emptying time of 15 minutes. No patient presented a gastric retention of >10% of the gastric meal at 4 hours. No patient complained of delayed gastric emptying symptoms. After esophagectomy, the transposition of the whole stomach without a pyloric drainage procedure seems to be an interesting option, simplifying the surgical procedure, and is not associated with delayed gastric emptying. After esophagectomy, the stomach is usually used to restore digestive continuity. To prevent postoperative delayed gastric emptying, most authors perform a gastric drainage procedure or transpose a tubulized stomach. The aim of our work is to evaluate the emptying of a transposed whole stomach without performing a pyloromyotomy or a pyloroplasty. From 1996 to January 2004, 45 patients underwent total esophagectomy for cancer or for caustic stenosis. Reconstruction of digestive continuity was realized through transposition of the whole stomach without performing a pyloric drainage procedure. At 12 months after the intervention, 35 patients (77.8%; 20 men and 15 women) were submitted to a gastric emptying scintigraphic study by means of ingestion of a mixed meal labeled with 37 MBq 99mTc-sulfur colloid. Mean half-emptying time was 71.4 minutes (range, 15-90 minutes; reference range, 83 ± 34 minutes): all the patients were in the normal range except one. No patient complained of delayed gastric emptying symptoms. After esophagectomy, the transposition of the whole stomach without a pyloric drainage procedure seems to be an interesting option, and is not associated with delayed gastric emptying.

Today, positron emission tomography (PET) using F-18 Fluoro-deoxyglucose (FDG) is, when available, the most important nuclear medicine procedure applied to oncology. Nevertheless, 2 main reasons for the clinical use of somatostatin analogues labeled with single photon emitting radionuclides are: a) the low accuracy of PET-FDG in neuroendocrine tumors (NET); b) the expression of somatostatin receptors (sstr) in most cells deriving from so-called neuroendocrine dispersed cells. The latter forms the premise for the use of radiolabeled somatostatin analogues, and (111)In pentetreotide (Octreo-scan) in particular, in the diagnosis of NET and other pathological conditions, including some benign diseases. Alongside diagnosis, staging and follow-up of NET, somatostatin analogues, whether radiolabeled or not, can have a role in evaluating prognosis and predicting therapeutic efficacy in cancer patients. Interesting indications have emerged with radioguided surgery and in diagnosing the activity of disease in patients with Graves' disease (exophthalmos), sarcoidosis, and rheumatoid arthritis. The pathophysiological premises to imaging, starting from an analysis of cells expressing sstr, binding affinity of octreotide for sstr, in vivo uptake of Octreoscan in lesions expressing or not sstr are discussed, as is the possible role of quantitative receptor scintigraphy in improving diagnostic accuracy based on tumor expression of sstr.

Thyroid cancer (TC) represents less than 1% of all newly diagnosed malignancies. In some selected cases, with a high clinical suspicion for disease but negative I-131 scan, positron emission tomography/computed tomography (PET) with F-18-Fluorodeoxyglucose (FDG) could be helpful in the detection of disease and the definition of its extent. FDG PET/CT, better if performed after TSH stimulation analogously to patient preparation done for radioiodine scintigraphy, could be useful mainly in the detection of metastatic and recurrent disease since the uptake and diagnostic sensitivity of FDG are increased by TSH stimulation. Recently, the role of oncogenic mutations in the tumorigenesis of TCs has become clearer. Among such mutations, BRAFV600E represents the most common genetic alteration. Mutated BRAF may define a more aggressive papillary carcinoma with poorer prognosis and therefore its analysis has been extensively studied as a rule-in test for thyroid carcinoma. In this paper, we try to outline the possible role of FDG PET/CT in the management of patients with TC and positive BRAF mutations and the impact that it could have on their therapeutic algorithm, in terms of thyroidectomy and radioactive iodine (RAI) therapy.

Background:Pancreatic Neuroendocrine Tumors (PNETs) are rare neoplasms, sporadic or familial, even being part of a syndrome. Their diagnosis is based on symptoms, hormonal disorders or may be fortuitous. The role of Nuclear Medicine is important, mainly because of the possibility of a theranostic strategy. This approach is allowed by the availability of biochemical agents, which may be labeled with radionuclides suitable for diagnostic or therapeutic purposes, showing almost identical pharmacokinetics. The major role for radiopharmaceuticals is connected with radiolabeled Somatostatin Analogues (SSA), since somatostatin receptors are highly expressed on some of the neoplastic cell types.Discussion:Nowadays, in the category of radiolabeled SSA, although 111In-pentetreotide, firstly commercially proposed, is still used, the best choice for diagnosis is related to the so called DOTAPET radiotracers labeled with 68-Gallium (Ga), such as 68Ga-DOTATATE, 68Ga-DOTANOC, and 68Ga-DOTATOC. More recently, labeling with 64-Copper (Cu) (64Cu-DOTATATE) has also been proposed. In this review, we discuss the clinical interest of a SAA (Tektrotyd©) radiolabeled with 99mTc, a gamma emitter with better characteristics, with respect to 111Indium, radiolabeling Octreoscan ©. By comparing both pharmacokinetics and pharmacodynamics of Octreoscan©, Tektrotyd© and PET DOTA-peptides, on the basis of literature data and of our own experience, we tried to highlight these topics to stimulate further studies, individuating actual clinical indications for all of these radiotracers.Conclusion:In our opinion, Tektrotyd© could already find its applicative dimension in the daily practice of NETs, either pancreatic or not, at least in centers without a PET/CT or a 68Ga generator. Because of wider availability, a lower cost, and a longer decay, compared with respect to peptides labeled with 68Ga, it could be also proposed, in a theranostic context, for a dosimetry evaluation of patients undergoing Peptide Receptor Radionuclide Therapy (PRRT), and for non-oncologic indications of radiolabelled SSA. In this direction, and for a more rigorous cost/effective evaluation, more precisely individuating its clinical role, further studies are needed.

Background:Pancreatic Neuroendocrine Tumors (P-NETs) are a challenge in terms of both diagnosis and therapy; morphological studies need to be frequently implemented with nonstandard techniques such as Endoscopic Ultrasounds, Dynamic CT, and functional Magnetic Resonance.Discussion:The role of nuclear medicine, being scarcely sensitive F-18 Fluorodeoxyglucose, is mainly based on the over-expression of Somatostatin Receptors (SSTR) on neuroendocrine tumor cells surface. Therefore, SSTR can be used as a target for both diagnosis, using radiotracers labeled with gamma or positron emitters, and therapy. SSTRs subtypes are capable of homo and heterodimerization in specific combinations that alter both the response to ligand activation and receptor internalization.Conclusion:Although agonists usually provide efficient internalization, also somatostatin antagonists (SS-ANTs) could be used for imaging and therapy. Peptide Receptor Radionuclide Therapy (PRRT) represents the most successful option for targeted therapy. The theranostic model based on SSTR does not work in insulinoma, in which different radiotracers such as F-18 FluoroDOPA or tracers for the glucagon-like peptide-1 receptor have to be preferred.

Although Somastostatin (SS) scintigraphy (SRS) has been introduced many years ago, it remains the most diffuse radionuclide diagnostic tool in patients with neuroendocrine tumours (NETs). Being SS receptors (SSTR) expressed in the majority of NETs, radiolabeled SS analogues (SS-A) provide high diagnostic accuracy, mainly in patients with gastro-entero-pancreatic (GEP) tumors. SSTR are the best target for radiotracers used either for diagnostic and therapeutic purposes in NETs due to their presence on the surface of neoplastic cells of clinical interest. 111In- DTPA-octreotide (111In-Pentetreotide, Octreoscan®), may detect either primitive or secondary lesions in the presence of a satisfactory lesion/background ratio. The unsatisfactory diagnostic performance of 18F-Fluorodeoxyglucose (18F-FDG), in NETs stimulated the synthesis of more specific positron-emitting tracers and SS-A labeled with 68Gallium (DOTA-peptides) represent actually the best radionuclide procedure for NET imaging. Alternative radiotracers, labeled either with gamma or positron emitters and showing different uptake mechanisms, as 18F-DOPA (Fluorine- 18-L-dihydroxyphenylalanine), have also been proposed and clinically utilized. Octreoscan®, despite its limitations, continue to represent the most frequently used method in evaluating the response to treatment and in follow-up of patients with NET, although the better diagnostic accuracy of DOTA-peptides.

Cardiovascular disease is a major cause of morbidity and mortality in chronic kidney disease. Radionuclide-based methods can be used for analyses on the perfusion of coronary arteries and ventricular function. The present study reports the use of a new procedure for continuous measurements of left ventricle function during a dialytic session with the use of a recently developed portable gamma radiation detector (ventricular function study system). On average, left ventricle ejection fraction and stroke volume progressively and continuously decreased throughout the session (end session versus baseline: -13.8% for ejection fraction, -25.9% for stroke volume, P < .02). A biphasic response was found for heart rate: a transient modest decrease (at session midpoint, -4.2%) followed by an increase up to values higher than baseline (end session, +4.7%). Cardiac output decreased by 10.4% at session midpoint (P = .023 versus baseline) without further reduction in the following hours. Mean changes in systolic pressure paralleled data for cardiac output. Individual changes in indices of left ventricle function were scattered and strongly were correlated with thickness of interventricular septum and telediastolic left ventricular volume measured by standard echocardiogram in the interdialytic period (R > .75, P < .05). Data indicate that the ventricular function study system could be a powerful tool for characterization of the profile of left ventricular function in hemodialyzed patients. © 2006 Elsevier Inc. All rights reserved.

The neuroendocrine tumors (NET) of the gastro-entero-pancreatic area (GEP) represent a heterogeneous group of malignancies from the histologic, clinico-laboratoristic (functioning and non-functioning variants), and therapeutic point of view. It is an issue becoming more frequent for the diagnostic imager, being radiologist as well as nuclear physician. Imaging (together with biopsy) plays a key role in the diagnostic assessment and staging (including grading and prognostic definition), in evaluating response to treatment, and in follow-up of GEP-NET. Multislice computed tomography (MSCT), octreoscan and PET-CT are the most widely diffuse and accurate imaging modalities employed in this setting. Other methods, such as Magnetic Resonance and Endoscopic Ultrasound, may also play a significant role.