Corinna Altini

The Copper Radioisotopes: A Systematic Review with Special Interest to 64Cu

Copper (Cu) is an important trace element in humans; it plays a role as a cofactor for numerous enzymes and other proteins crucial for respiration, iron transport, metabolism, cell growth, and hemostasis. Natural copper comprises two stable isotopes, 63Cu and 65Cu, and 5 principal radioisotopes for molecular imaging applications (60Cu, 61Cu, 62Cu, and 64Cu) and in vivo targeted radiation therapy (64Cu and 67Cu). The two potential ways to produce Cu radioisotopes concern the use of the cyclotron or the reactor. A noncopper target is used to produce noncarrier-added Cu thanks to a chemical separation from the target material using ion exchange chromatography achieving a high amount of radioactivity with the lowest possible amount of nonradioactive isotopes. In recent years, Cu isotopes have been linked to antibodies, proteins, peptides, and nanoparticles for preclinical and clinical research; pathological conditions that influence Cu metabolism such as Menkes syndrome, Wilson disease, inflammation, tumor growth, metastasis, angiogenesis, and drug resistance have been studied. We aim to discuss all Cu radioisotopes application focusing on 64Cu and in particular its form 64CuCl2 that seems to be the most promising for its half-life, radiation emissions, and stability with chelators, allowing several applications in oncological and nononcological fields.

A retrospective study comparing contrast-enhanced computed tomography with 18F-FDG-PET/CT in the early follow-up of patients with retroperitoneal sarcomas.

ObjectiveTo compare 18-fluorine-labeled 2-deoxy-2-fluoro-D-glucose PET/computed tomography (18F-FDG-PET/CT) with contrast enhancement computed tomography (CECT) in the early follow-up of patients who had undergone treatment for primitive retroperitoneal sarcomas (RS). MethodsThis is a retrospective study on 24 patients who underwent 18F-FDG-PET/CT and CECT within 2 years after therapy for RS. 18F-FDG-PET/CT and CECT results were compared with results of histological examination and clinical–instrumental follow-up. We calculated the sensitivity and specificity of CECT and 18F-FDG-PET/CT for retroperitoneal recurrences and compared them with results of the McNemar test. Negative predictive values (NPVs) and positive predictive values (PPVs) were calculated and the positive percentage agreement and negative percentage agreement were evaluated. ResultsThe sensitivity and specificity of 18F-FDG-PET/CT were 66.7 and 100% and those for CECT were 58.3 and 50%, respectively. For 18F-FDG-PET/CT, PPV was 100% [95% confidence interval (CI): 67–100%] and NPV was 75% (95% CI: 58–75%); for CECT, PPV was 54% (95% CI: 33–73%) and NPV was 55% (95% CI: 30–78%). Positive percentage agreement and negative percentage agreement were, respectively, 38 and 72% for retroperitoneal lesions, 42.8 and 100% for liposarcomas, 40 and 50% for leiomyosarcomas, 14.2 and 94% for abdominal lymph nodes, and 16.6 and 100% for lung metastasis. Neither technique gave reliable results for liver metastasis. ConclusionOur data show that 18F-FDG-PET/CT has a higher overall specificity compared with CECT in identifying areas of recurrence, demonstrating its validity for early whole-body detection of lesions. In our hands 18F-FDG-PET/CT seems to be a good tool in the early follow-up of patients experiencing recurrence of RS.

Cardiovascular risk evaluation and prevalence of silent myocardial ischemia in subjects with asymptomatic carotid artery disease

Introduction: Silent ischemia is an asymptomatic form of myocardial ischemia, not associated with angina or anginal equivalent symptoms, which can be demonstrated by changes in ECG, left ventricular function, myocardial perfusion, and metabolism. The aim of this study was to evaluate the prevalence of silent myocardial ischemia in a group of patients with asymptomatic carotid stenosis. Methods: A total of 37 patients with asymptomatic carotid plaques, without chest pain or dyspnea, was investigated. These patients were studied for age, sex, hypertension, diabetes, dyslipidemia, smoking, and family history of cardiac disease, and underwent technetium-99 m sestamibi myocardial stress-rest scintigraphy and echo-color Doppler examination of carotid arteries. Results: A statistically significant relationship (P = 0.023) was shown between positive responders and negative responders to scintigraphy test when both were tested for degree of stenosis. This relationship is surprising in view of the small number of patients in our sample. Individuals who had a positive scintigraphy test had a mean stenosis degree of 35% ± 7% compared with a mean of 44% ± 13% for those with a negative test. Specificity of our detection was 81%, with positive and negative predictive values of 60% and 63%, respectively. Conclusion: The present study confirms that carotid atherosclerosis is associated with coronary atherosclerosis and highlights the importance of screening for ischemic heart disease in patients with asymptomatic carotid plaques, considering eventually plaque morphology (symmetry, composition, eccentricity or concentricity of the plaque, etc) for patient stratification.

18F-FDG PET/CT role in staging of gastric carcinomas: comparison with conventional contrast enhancement computed tomography.

AbstractThe purpose of the report was to evaluate the role of fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in staging gastric cancer comparing it with contrast enhancement computed tomography (CECT).This retrospective study included 45 patients who underwent performed whole body CECT and 18F-FDG PET/CT before any treatment. We calculated CECT and 18F-FDG PET/CT sensitivity, specificity, accuracy, positive and negative predictive values (PPV and NPV) for gastric, lymphnode, and distant localizations; furthermore, we compared the 2 techniques by McNemar test. The role of 18F-FDG PET/CT semiquantitative parameters in relation to histotype, grading, and site of gastric lesions were evaluated by ANOVA test.Sensitivity, specificity, accuracy, PPV and NPV of CECT, and 18F-FDG PET/CT for gastric lesion were, respectively, 92.11%, 57.14%, 86.66%, 92.11%, 57.14% and 81.58%, 85.71%, 82.22%, 96.88%, 46.15%. No differences were identified between the 2 techniques about sensitivity and specificity. No statistical differences were observed between PET parameters and histotype, grading, and site of gastric lesion. The results of CECT and 18F-FDG PET/CT about lymphnode involvement were 70.83%, 61.90%, 66.66%, 68%, 65% and 58.33%, 95.24%, 75.55%, 93.33%, 66.67%. The results of CECT and 18F-FDG PET/CT about distant metastases were 80%, 62.86%, 66.66%, 38.10%, 91.67% and 60%, 88.57%, 82.22%, 60%, 88.57%. 18FDG PET/CT specificity was significantly higher both for lymphnode and distant metastases.The 18F-FDG PET/CT is a useful tool for the evaluation of gastric carcinoma to detect primary lesion, lymphnode, and distant metastases using 1 single image whole-body technique. Integration of CECT with 18F-FDG PET/CT permits a more valid staging in these patients.

18 F-FDG PET/CT contribution to diagnosis and treatment response of rhino-orbital-cerebral mucormycosis

OBJECTIVE Mucormycosis is an infection caused by mycetes mucorales, emerged as a life-threatening infection associated with severe morbidity and high mortality. Conventional imaging such as computed tomography (CT) and magnetic resonance imaging (MRI) are usually performed to assess mucormycosis extension, but they may present insufficiencies in their performance. CASE PRESENTATION We present the case of a 13 years old patient with diagnosis of rhino-orbital-cerebral mucormycosis (RCM) who performed head MRI and [(18)F]2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) both for the infection spread assessment and for the early evaluation of response to systemic amphotericin-B treatment. CONCLUSION This case suggests that (18)F-FDG PET/CT could be considered as a valuable tool for the initial staging of RCM when compared with MRI and should be performed as soon as possible after the first clinical suspicion of this disease. In addition (18)F-FDG PET/CT may also be useful for the assessment of response to treatment.

18F-FDG PET/CT in suspected recurrences of epithelial malignant pleural mesothelioma in asbestos-fibers-exposed patients (comparison to standard diagnostic follow-up)

This retrospective study evaluated the role of 18-fluorine-labeled 2-deoxy-2-fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with previous occupational or environmental exposure to asbestos, with histopathological diagnosis of epithelial malignant pleural mesothelioma and suspected recurrences, comparing the data from 18F-FDG PET/CT and computed tomography with contrast enhancement (CECT). 18F-FDG PET/CT has greater sensitivity than CECT in identifying local extent, lymph nodes, and metastasis. 18F-FDG PET/CT whole-body explorations are useful to monitor the follow-up and evaluate the metabolic response to chemo- and radiotherapy, modifying the scheduled treatment plan.

124Iodine: A Longer-Life Positron Emitter Isotope—New Opportunities in Molecular Imaging

124Iodine (124I) with its 4.2 d half-life is particularly attractive for in vivo detection and quantification of longer-term biological and physiological processes; the long half-life of 124I is especially suited for prolonged time in vivo studies of high molecular weight compounds uptake. Numerous small molecules and larger compounds like proteins and antibodies have been successfully labeled with 124I. Advances in radionuclide production allow the effective availability of sufficient quantities of 124I on small biomedical cyclotrons for molecular imaging purposes. Radioiodination chemistry with 124I relies on well-established radioiodine labeling methods, which consists mainly in nucleophilic and electrophilic substitution reactions. The physical characteristics of 124I permit taking advantages of the higher PET image quality. The availability of new molecules that may be targeted with 124I represents one of the more interesting reasons for the attention in nuclear medicine. We aim to discuss all iodine radioisotopes application focusing on 124I, which seems to be the most promising for its half-life, radiation emissions, and stability, allowing several applications in oncological and nononcological fields.

Prospective analysis of 18F-FDG PET/CT predictive value in patients with low rectal cancer treated with neoadjuvant chemoradiotherapy and conservative surgery.

This study prospectively assessed 18F-FDG PET/CT in predicting the response of locally advanced low rectal cancer (LRC) to neoadjuvant chemoradiation (nCRT). Methods. 56 patients treated with chemoradiation underwent two 18F-FDG PET/CT scans (baseline and 5-6 weeks post-nCRT). 18F-FDG uptake (SUVmax and SUVmean) and differences between baseline (SUV1) and post-nCRT (SUV2) scans (ΔSUV and RI%) were evaluated. Results were related to the Mandards TRG and (y)pTNM. Results. 18F-FDG PET/CT sensitivity, specificity, accuracy, PPV and NPV resulted in 88.6%, 66.7%, 83.92%, 90.7%, and 61.5%. SUV2 resulted in better than SUV1 to predict nCRT response by TRG, with no significant statistical difference between the SUVmax2 and SUVmean2 AUC (0.737 versus 0.736; P = 0.928). The same applies to the (y)pTNM (0.798 versus 0.782; P = 0.192). In relation to the TRG, RI values had a higher AUC than ΔSUV, with no significant difference between RImax and RImean (0.672 versus 0.695; P = 0.292). The same applied to the (y)pTNM (0.742 versus 0.741; P = 0.940). In both cases ΔSUV does not appear to be a good predictive tool. Logistic regression confirmed the better predictive role of SUVmax2 for the (y)pTNM (odds ratio = 1.58) and SUVmean2 for the TRG (odds ratio = 1.87). Conclusions. 18F-FDG PET/CT can evaluate response to nCRT in LRC, even if more studies are required to define the most significant parameter for predicting pathologic tumor changes.

F-18 FDG PET/CT in the diagnosis of a rare case of neurosarcoidosis in a patient with diabetes insipidus.

We report a case of a 26-year-old man who had sarcoidosis with involvement of central nervous system, manifested by symptoms attributable to diabetes insipidus. Laboratory tests, magnetic resonance and computed tomography images, were all partially useful and inconclusive. These investigations have been integrated with 18-Fluorine-labeled-2-deoxy-2-fluoro-Dglucose positron-emission-tomography/computed tomography (F-18 FDG PET/CT), which showed F-18 FDG uptake in the midbrain area and pituitary gland, corresponding to magnetic resonance findings, and in many bone sites, in particular iliac wings. This finding has been useful for biopsy. F-18 FDG PET/CT can demonstrate active skull-base sarcoidosis.

La carcinosi peritoneale da carcinoma ovarico: utilità della 18F-FDG-PET/TC e del biomarker CA125

The purpose of this study was to evaluate the contribution of 18F-FDG-PET/CT in highlighting the peritoneal involvement in patients with ovarian cancer, also in relation to the biomarker CA125. We retrospectively analyzed 64 female patients with histological diagnosis of ovarian cancer who underwent 18F-FDG-PET/CT and CA125 measurement. Sensitivity and specificity of 18F-FDG-PET/CT were both 90.63% (95% CI: 80-100%). Sensitivity and specificity of CA125 were 93.33% (95% CI: 80-100%) and 33.33% (95% CI: 25-64%), respectively. In patients with peritoneal carcinomatosis from ovarian cancer, it is recommended to perform 18F-FDG-PET/CT, in particular when elevated CA125 levels are detected.