Notaristefano A

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.

Whole-body MR-DWIBS vs. [18F]-FDG-PET/CT in the study of malignant tumors: a retrospective study

PurposeOur aim was to assess the overall diagnostic accuracy of magnetic resonance diffusion-weighted whole-body imaging with background signal suppression (MR-DWIBS) compared with ([18F]-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT), considered the reference standard of whole-body tumour imaging modalities, in a series of consecutive patients with malignant tumour.Materials and methodsThirty-eight patients diagnosed with a malignant tumour over a 4-month period were enrolled in this retrospective, observational study. PET/CT and MR-DWIBS images were reviewed in double-blind manner by a nuclear medicine physician and radiologists with 4 years experience. Lesion size, standard uptake value (SUV) and apparent diffusion coefficient (ADC) were measured and calculated for each lesion.ResultsThe qualitative analysis of MR-DWIBS and [18F]-FDG-PET/CT showed that two patients were negative at both techniques. MR-DWIBS was positive in 36 patients, 34 of whom were positive and two negative at [18F]-FDG-PET/CT, respectively. Two hundred and fifty-five lesions were identified by MR-DWIBS and 184 by [18F]-FDG-PET/CT, which was a significative discordance. Correlation between SUV and ADC of lesions positive at both techniques was not statistically significant. The mean difference between lesion size in [18F]-FDG-PET/CT and MR-DWIBS was not statistically significant. No correlation was found between glucose metabolism and water motion.ConclusionsMR-DWIBS may be used to evaluate localisation of parenchymal neoplasms but is less efficacious in characterising lymph-node and skeletal lesions. [18F]-FDG-PET/CT remains the best whole-body technique to identify lymph-node and skeletal lesions, but its limitation is identifying tumours with low glucose metabolism as in mucinous neoplasms. MR-DWIBS evaluation must be integrated with morphological images to increase MR diagnostic accuracy.RiassuntoObiettivoL’obiettivo del nostro lavoro è stato stabilire il valore di accuratezza diagnostica della whole-body risonanza magnetica (RM)-diffusion weighted whole body imaging with background signal suppression (DWIBS) rispetto alla 18F-fluor-deossiglucosio (FDG)-tomografia a emissione di positroni (PET)/tomografia computerizzata (TC), considerata il gold standard nell’ambito della diagnostica whole body nell’imaging dei tumori, in un gruppo di pazienti con diagnosi di neoplasia maligna.Materiali e metodiSono stati inclusi 38 pazienti con diagnosi di neoplasia maligna in un periodo di 4 mesi. Le immagini PET/TC e RM-DWIBS sono state rivalutate in doppio cieco da un medico nucleare e da un radiologo con 4 anni di esperienza. Per ciascuna lesione sono state valutate dimensioni, standardized uptake value (SUV) e coefficiente di diffusione apparente (ADC).RisultatiLa valutazione qualitativa sia della MR-DWIBS che della 18F-FDG-PET/TC ha riscontrato due soli pazienti negativi per entrambe le tecniche. La RM-DWIBS è risultata positiva in 36 pazienti, di cui 34 erano positivi e 2 risultavano negativi alla 18F-FDG-PET/TC. Duecentocinquantacinque lesioni sono state identificate con la MR-DWIBS e 184 con 18F-FDG-PET/TC. È stata dimostrata una discordanza significativa. La correlazione tra SUV e ADC nelle lesioni positive ad entrambe le tecniche non è risultata statisticamente significativa. La differenza media tra la dimensione delle lesioni alla 18F-FDG-PET/TC e alla RM-DWIBS non è risultata statisticamente significativa. Non è stata dimostrata alcuna correlazione tra il metabolismo glucidico e i movimenti di diffusione.ConclusioniI risultati di questo studio retrospettivo dimostrano che la RM-DWIBS può essere utilizzata per studiare le localizzazioni parenchimali e scheletriche di neoplasia, ma che essa risulta meno efficacie nella caratterizzazione delle lesioni linfonodali. La 18F-FDG-PET/TC resta la tecnica migliore per valutare le lesioni linfonodali. Il limite della 18F-FDG-PET/TC è identificare tumori con basso metabolismo glucidico come le neoplasie mucinose. Lo studio RM-DWIBS deve essere integrato con immagini morfologiche per aumentarne l’ accuratezza diagnostica.

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 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.

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.

[18F-FDG PET/CT in staging and restaging cholangiocarcinoma].

The prognosis for hepatobiliary malignancies is dismal. Surgery remains the primary curative option. The positron emission tomography/computed tomography (PET/CT) provides simultaneous metabolic and anatomic information on tumors in the same imaging session. The role of PET/CT in detecting hepatobiliary malignancies has not yet been established. The purpose of this review was to examine the literature on the use of PET/CT in cholangiocarcinomas, also in order to improve the preoperative staging and the restaging, for a proper oncology management of patients.

[The PET/CT with 18F-fluorocholine in the diagnosis of gliomatosis cerebri type 2].

In a patient with cerebral gliomatosis type II MRI revealed a large area of altered signal in the temporal region, parietal and occipital lobes associated with a single nodule with perilesional contrast enhancement, which showed increased uptake on PET/CT with 18F-FCH, characterizing heterogeneous cellularity of the tumor.