Lorenzo Fantini

68Ga-Citrate PET/CT for Evaluating Patients with Infections of the Bone: Preliminary Results

The aim of this work was to preliminarily evaluate the sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of 68Ga-citrate PET/CT in a population of patients with suspected bone infections. Methods: We enrolled 31 patients with suspected osteomyelitis or diskitis who underwent a total of forty 68Ga-citrate PET/CT scans. The results were compared with different combinations of diagnostic procedures (MRI, radiography, CT, or white blood cell scintigraphy), biopsy (when diagnostic), and follow-up data (at least 1 y) to determine the performance of 68Ga-citrate PET/CT. Results: We found a sensitivity of 100%, a specificity of 76%, a positive predictive value of 85%, a negative predictive value of 100%, and an overall accuracy of 90%. Conclusion: Although preliminary, these data confirm a possible role for 68Ga-citrate in the diagnosis of bone infections, especially in consideration of its favorable characteristics.

The role of 11C-choline PET imaging in the early detection of recurrence in surgically treated prostate cancer patients with very low PSA level <0.5 ng/mL.

Purpose This study aims to evaluate the role of 11C-choline PET/CT in patients with biochemical relapse after radical prostatectomy (RP) showing prostate-specific antigen (PSA) values lower than 0.5 ng/mL. Methods We performed 11C-choline PET/CT in 71 consecutive patients previously treated with RP showing PSA values lower than 0.5 ng/mL. 11C-Choline PET/CT was performed following standard procedure. 11C-Choline PET/CT–positive findings were validated by transrectal ultrasonography + biopsy, repeated 11C-choline PET/CT, other conventional imaging modality, and histology. Results 11C-Choline PET/CT was true positive in 15/71 (21.1%). 11C-Choline uptake was observed in pelvic lymph nodes (7/71; 9.9%), in the prostatic bed (7/71; 9.9%), and in bone (1/71; 1.4%). Mean PSA, PSA doubling time (PSAdt), and PSA velocity (PSAvel) values ± SD in 11C-choline PET/CT–positive patients was 0.37 ± 0.1 ng/mL, 3.4 ± 2.1 months, and 0.05 ± 0.1 ng/mL/yr, respectively. 11C-Choline PET/CT was false negative in 2 patients and false positive in 1 patient. Among all variables, only PSAdt and the ongoing hormonal treatment were statistically significant in the prediction of a positive 11C-choline PET/CT at multivariate analysis. Conclusions 11C-Choline PET/CT could be used early after biochemical failure even if PSA values are very low, preferentially in hormonal resistant patients showing fast PSA kinetics. An early detection of the site of relapse could lead to a personalized and tailored treatment.

Non FDG PET

2- [(18)F]-fluoro-2-deoxy-D-glucose (FDG) is the radiopharmaceutical most frequently used for clinical positron emission tomography (PET). However, FDG cannot be used for many oncological, cardiological, or neurological conditions, either because the abnormal tissue does not concentrate it, or because the tissues under investigation demonstrate high physiological glucose uptake. Consequently, alternative PET tracers have been produced and introduced into clinical practice. The most important compounds in routine practice are (11)C-choline and (18)F-choline, mainly for the evaluation of prostate cancer; (1)C-methionine for brain tumours; (118)F-DOPA ((18)F-deoxiphenilalanine) for neuroendocrine tumours and movement disorders; (68)Ga-DOTANOC (tetraazacyclododecanetetraacetic acid-[1-Nal3]-octreotide) and other somatostatin analogues for neuroendocrine tumours; 11C-acetate for prostate cancer and hepatic masses and 18F-FLT (3-deoxy-3-fluorothymidine) for a number of malignant tumours. Another impetus for the development of new tracers is to enable the investigation of biological processes in tumours other than glucose metabolism. This is especially important in the field of response assessment, where there are new agents that are targeted more specifically at angiogenesis, hypoxia, apoptosis and other processes.

Hydrogen Sulfide, Nitric Oxide and a Molecular Mass 66 u Substance in the Exhaled Breath of Chronic Pancreatitis Patients

Background/Aims: Human exhaled breath contains many molecules either present as gases or occurring in a soluble form in the vapor of the breath. This study was designed to evaluate the substances present in the exhaled breath of chronic pancreatitis (CP) patients. Subjects: Thirty-one consecutive CP patients (11 with exocrine insufficiency) and 31 healthy subjects (HS) were studied. Methods: Ninety-eight different substances were analyzed using a mass spectrometer on a breath sample from all subjects and on each respective ambient air sample. Results: H2S, NO and a substance having a molecular mass of 66 u (M66) were those which had significantly higher concentrations in CP patients than in HS after adjustment for the ambient air; the estimated increases attributable to the disease were 14% (p = 0.040) for H2S, 84% (p = 0.006) for M66 and 50% (p = 0.033) for NO, but the three volatile compounds showed poor diagnostic accuracy in differentiating CP patients from HS (AUC-ROC: 0.664, 0.715, and 0.602 for H2S, M66, and NO, respectively). Finally, no significant differences of H2S, M66, and NO were found between patients with and without alcoholic pancreatitis as well as between patients with and without pancreatic insufficiency. Conclusions: Exhaled breath analysis can rapidly and easily assess the presence of volatile compounds (H2S, NO and a substance having a molecular mass of 66 u) which may have properties capable of explaining, at least in part, the pathogenesis of CP.

Fecal calprotectin and elastase 1 determinations in patients with pancreatic diseases: a possible link between pancreatic insufficiency and intestinal inflammation

BackgroundFecal calprotectin determination has been demonstrated to be useful in diagnosing various inflammatory diseases of the gastrointestinal tract; however, data available for patients with pancreatic diseases are scarce. Our aim was to assess fecal calprotectin in order to evaluate the presence of intestinal inflammation in patients with pancreatic disease.MethodsEligible patients with suspected pancreatic illness were enrolled, and in all of them fecal calprotectin and elastase-1, as well as serum amylase and lipase activities, were assayed using commercially available kits.ResultsA total of 90 subjects (47 men, 43 women, mean age 58.6 ± 14.9 years) were enrolled: 20 (22.2%) had chronic pancreatitis; 15 (16.7%) had pancreatic cancer; six (6.7%) had chronic nonpathological pancreatic hyperenzymemia; 16 (17.8%) had nonpancreatic diseases; and 23 (25.6%) had no detectable diseases. Diarrhea was present in 19 patients (21.1%). In univariate analyses, the presence of diarrhea and low fecal elastase-1 concentrations were significantly associated (P = 0.019 and P = 0.002, respectively) with abnormally high fecal calprotectin concentration, and the multivariate analysis demonstrated that low fecal elastase-1 concentration was the only variable independently associated with a high fecal calprotectin concentration.ConclusionsPancreatic insufficiency may cause intestinal inflammation, probably because of a modification of the intestinal ecology.

Serum adhesion molecules in acute pancreatitis: Time course and early assessment of disease severity

Objectives: To evaluate the adhesion molecule time course in the early phases of acute pancreatitis and to explore the usefulness of these proteins in assessing the severity of the disease. Fifteen consecutive acute pancreatitis patients (10 patients with the mild and 5 with the severe disease) admitted to the hospital within 6 hours after the onset of pain and 15 age- and sex-matched healthy subjects. Methods: Vascular cell adhesion molecule 1, intercellular adhesion molecule 1, E-selectin, P-selectin, and L-selectin were quantified on hospital admission and for the following 2 days. Results: Acute pancreatitis patients had vascular cell adhesion molecule 1 and P-selectin concentrations significantly lower and L-selectin concentrations significantly higher than the healthy subjects. Only E-selectin was significantly higher in severe than in mild disease (P = 0.029); a value of E-selectin ranging from 3.83 to 3.92 ng/mL was the best cutoff value for differentiating severe from mild acute pancreatitis (sensitivity: 60.0%, specificity: 90.0%, cases correctly classified: 80%). E-selectin and P-selectin entered the multivariate logistic regression analysis, and a score was calculated showing a sensitivity of 93.3% and a specificity of 86.7% in identifying the patients with severe pancreatitis. Conclusions: This score seems to be useful for the early assessment of the severity of acute pancreatitis.Abbreviations: VCAM-1 - vascular cell adhesion molecule 1, ICAM-1 - intercellular adhesion molecule 1

Management of acute pancreatitis: current knowledge and future perspectives

In recent years, a number of articles have been published on the treatment of acute pancreatitis in experimental models and most of them concerned animals with mild disease. However, it is difficult to translate these results into clinical practice. For example, infliximab, a monoclonal TNF antibody, was experimentally tested in rats and it was found to significantly reduce the pathologic score and serum amylase activity and also to alleviate alveolar edema and acute respiratory distress syndrome; however, no studies are available in clinical human acute pancreatitis. Another substance, such as interleukin 10, was efficacious in decreasing the severity and mortality of lethal pancreatitis in rats, but seems to have no effect on human severe acute pancreatitis. Thus, the main problem in acute pancreatitis, especially in the severe form of the disease, is the difficulty of planning clinical studies capable of giving reliable statistically significant answers regarding the benefits of the various proposed therapeutic agents previously tested in experimental settings.According to the pathophysiology of acute pancreatitis, the efficacy of the drugs already available, such as gabexate mesilate, lexipafant and somatostatin should be re-evaluated and should be probably administered in a different manner. Of course, also in this case, we need adequate studies to test this hypothesis.

Serous Cystic Tumors of the Pancreas: When to Observe and When to Operate

Background: Pancreatic serous cystic tumors are considered to have a benign biological and clinical course with only few malignant cases. Methods: We retrospectively analyzed data from 26 patients affected by serous cystic tumors consecutively observed in our Pancreas Unit. We explored the different clinical pictures in operated and nonoperated patients. Results: Eighteen of the 26 patients were female (69%), median age at diagnosis was 61.5 years and 20 patients (77%) underwent surgery. The median diameter of the tumors was greater in patients who underwent surgery than in those who did not (5.5 versus 2.3 cm, p < 0.001). Major pancreatic resections were carried out in 15 of the 20 operated patients (75%). Postoperative morbidity and mortality were 20 and 5%, respectively. During follow-up, there was no observed development of malignancy or any significant increase in the diameter of the lesion among nontreated patients. Conclusions: In asymptomatic patients with a clear imaging diagnosis of serous cystic tumor a wait and see management should be recommended, with a careful follow-up. Surgery should be suggested in symptomatic patients or when the preoperative diagnosis is doubtful.