Clinical indications to the use of (99m)Tc-EDDA/HYNIC-TOC to detect somatostatin receptor-positive neuroendocrine tumors.

The aim of this study was to define, retrospectively, the utility to perform (99m)Tc-EDDA/HYNIC-Tyr3-octreotide ((99m)Tc-EDDA/HYNIC-TOC) scan in patients with NET. We studied 50 consecutive patients affected by different types of NET and divided in two groups. Group 1: 34 patients with known lesions in which (99m)Tc-EDDA/HYNIC-TOC was performed for staging, characterisation or to choose the appropriate treatment. Group 2: 16 patients suspected of having NET or in follow up after surgery. Patients were injected with 370 MBq of (99m)Tc-EDDA/HYNIC-Tyr3-octreotide and whole-body and SPET images acquired 2-3 hours after injection. Overall, 29 patients (58%) had a positive scan, with a sensitivity, specificity and accuracy of 70.3%, 76.9% and 72%, respectively (78.1%, 50% and 76.5%, in group 1 and 20%, 81.2%, 62.5% in group 2). In patients from group 1 (99m)Tc-HYNIC-TOC scintigraphy showed a concordance of 68% with another imaging procedure and in 9 patients revealed a greater number of lesions. In the second group, false negative results were especially found in patients with medullary thyroid cancer with negative radiological findings and elevated calcitonin. In conclusion, (99m)Tc-EDDA/HYNIC-TOC is highly indicated for in vivo histological characterization of known NET lesions, previously identified by other imaging modalities or biopsy, to plan appropriate therapy especially for patients with inoperable disease. In patients with only biochemical suspicion of NET and in those with negative markers, this scintigraphy does not significantly modify the clinical management.

Pancreatic scintigraphy with 99mTc-interleukin-2 at diagnosis of type 1 diabetes and after 1 year of nicotinamide therapy.

BACKGROUND: To evaluate the clinical utility of pancreatic scintigraphy with 99mTc-interleukin-2 to identify Type 1 diabetic patients with pancreatic inflammation at diagnosis. METHODS: 99mTc-interleukin-2 scintigraphy was performed on 42 newly diagnosed Type 1 diabetic patients, before and after 1 year of treatment with nicotinamide (25 or 50 mg/kg/day) in addition to intensive insulin therapy. Metabolic status was monitored every 3 months for 1 year. Sixteen normal subjects were studied as control. RESULTS: Significant pancreatic accumulation of 99mTc-interleukin-2 was found in 31% of the patients at the time of diagnosis. Patients positive or negative for pancreatic accumulation of interleukin-2 scintigraphy did not show any difference in metabolic or immunologic parameters at diagnosis. Positive patients, however, showed higher C-peptide values at 3 months and lower insulin requirement at 1 year, compared to negative patients (insulin requirement (IR): 0.33+/-0.11 vs 0.67+/-0.24 IU/kg/day, positive vs negative patients; p=0.0001); patients positive to IL2 scintigraphy treated with nicotinamide at 25 mg/kg were the only group showing a significant reduction in IR 1 year after diagnosis (IRt0: 0.53+/-0.30 vs IRt12: 0.28+/-0.07 IU/kg/day; p=0.013). After 1 year, all the positive patients showed a significant decrease in pancreatic uptake of 99mTc-interleukin-2 (P/B: 7.87+/-2.28 at diagnosis vs 5.00+/-1.23 after 1 year; p<0.0001 paired t-test). CONCLUSION: 99mTc-interleukin-2 scintigraphy at diagnosis of Type 1 diabetes may identify patients with pancreatic inflammation. In such patients, treated with nicotinamide at 25 mg/kg, insulin requirement and pancreatic inflammation after 1 year were significantly reduced suggesting that IL2 scintigraphy may be of potential use for assessing the autoimmune phenomena in endocrine pancreas.

The developing role of peptide radiopharmaceuticals in the study of chronic inflammation: new techniques for novel therapeutic options.

Chronic inflammatory diseases usually lead to fibrosis of the target organ and consequent hypo function. They are often relapsing, invalidating and require life-long treatment. In this class of patients it is very important to try and achieve specific immune suppression to extinguish the immune process with the aim of preventing the disease, preventing or delaying complications and avoiding disease relapse, often requiring surgical intervention. It is important that, while attempting to improve the quality of life of these patients by means of anti-inflammatory drugs, side effects are reduced to a minimum via the use of specific immune therapies that block as selectively as possible the pathologic mechanism responsible for the disease. New therapeutic options are being developed for specific targeted therapies. Several trials are being performed to assess the efficacy and safety of this approach. All of them, however, rely on the clinical assessment of the patients to evaluate the effect of treatment. It would be important to use an objective and reliable method to highlight directly the immune process underlying the individual disease. This manuscript reviews the radiopharmaceuticals available or recently developed for imaging chronic inflammatory diseases and their use for therapy decision making and follow-up.