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PURPOSE Recently new mobile systems for dispensing positron emitters have been produced, designed to guarantee dispensing cycles in an aseptic environment. The aim of the present work was to assess the advantage of one of these systems in radiation protection of operators in clinical settings. METHODS Recently, in our centre the new self-dispensing system named KARL100 by Tema Sinergie was adopted for 18F-FDG radiopharmaceuticals. The system is associated with an automatic Rad-inject infuser. The system that was previously used was a fixed isolator NMC DSI (Tema Sinergie), equipped with a μDDS-An activity fractioning system, together with a pneumatic post for the syringe delivery. The dosimetric evaluations on both systems were carried out through environmental measurements with an ionisation chamber and with the use of personal dosimeters. RESULTS The operations of preparation and administration of 18F-FDG dose to the patient, with the use of Karl100 + RadInject, involve exposures much lower than those obtained by the fixed isolator. The average body exposure of the technician was reduced by 31%, and for the physician by 77%. On the extremities, the equivalent dose to the hands of the technician was reduced by 78%, and for the physician by 96%. Also the additional dosimeters worn by the technician confirmed the estimated environmental assessments. CONCLUSIONS The exposures of the working personnel were significantly reduced with the introduction of the new KARL100 system.

Coronavirus disease (COVID-19) outbreak has profoundly changed the organization of hospital activities. We present our experience of reorganization of a nuclear medicine service settled in Northern Italy during the pandemic period of March and April 2020 characterized a government-mandated lockdown. Our service remained open during the whole period, performing approximately 80% of the routine practice, while maintaining it COVID-free despite the geographical context characterized by a high risk of infection. Reorganization involved all aspects of a nuclear medicine department, following local, national, and international guidelines for prioritizing patients, telephone and physical triages, deployment of appropriate personal protective equipment, social distancing, and logistic changes for scheduling examinations and disinfection procedures. All staff remained COVID-19-negative despite the unintentional admission of 4 patients who later turned out to be positive for the severe acute respiratory syndrome coronavirus 2. These adopted measures would serve as the basis for safe nuclear medicine services in the post-lockdown phase.

Recently new mobile systems for dispensing positron emitters have been produced, designed to guarantee dispensing cycles in an aseptic environment. The aim of the present work was to assess the advantage of one of these systems in radiation protection of operators in clinical settings.Recently, in our centre the new self-dispensing system named KARLThe operations of preparation and administration ofThe exposures of the working personnel were significantly reduced with the introduction of the new KARL

OBJECTIVE: Lung nodules can be benign or malignant, reflecting many possible causes, ranging from inflammatory and infectious processes to neoplasms. Incidental detection on chest x-ray or thoracic CT often requires further evaluation by imaging or invasive procedures. CONCLUSION: Currently, 18F-FDG PET/CT offers both anatomic and metabolic characterization of lung nodules. Fluorine-18-thymidine, 11C-methionine, 68Ga-DOTA-somatostatin analogs, and 18F-dihydroxyphenylalanine may offer additional molecular information useful for diagnosis and treatment planning.

Aim The aim of the study was to assess the prevalence of focal fluorine-18 fluorodeoxyglucose (18F-FDG) activity in the lungs using 18F-FDG PET/computed tomography (CT) without matching CT findings. Materials and methods A total of 10,500 consecutive 18F-FDG PET/CT records over 4 years were reviewed for focal incongruence between PET and CT, potentially indicating an artifact 18F-FDG (2.2 MBq/kg) was injected through a butterfly needle, followed by a 10 ml saline flush. Non-contrast-enhanced low-dose CT (140 kV and 40-80 mA) was coregistrated with PET. Results Sixteen patients (12 men and four women; mean age 63 years, range 44-83) had focal pulmonary areas of high 18F-FDG activity [mean maximum standardized uptake value (SUV max) 15.8; range 3.5-81.0], typically peripheral, with a mean maximum diameter of 1.3 cm (range 0.5-2.2 cm) on PET. 18F-FDG focality was singular in 14 patients, whereas two patients had two foci each. None had corresponding CT abnormalities. Identification of these 'focalities' during the acquisition phase led to late respiratory gated thoracic PET acquisitions in eight patients at 2 h with no significant changes in the location or size of the 'focalities'. Five PET/CTs repeated at 48 h did not confirm the 'focalities'. Five had negative follow-up contrast-enhanced CT. 18F-FDG-positive 'focalities' at PET/CT without anatomical correlation findings were considered as 'artefactual accumulation' of the tracer. Conclusion In the absence of morphological abnormality, focal pulmonary 18F-FDG activity is very rare (1.5 cases/1000 PET scans) but potentially very 'dangerous'. Artefact identification during acquisition can lead to late respiratory gated images for more confident interpretation, avoiding erroneous reports or further imaging procedures.

Primary degenerative dementia syndromes are an increasingly relevant problem worldwide because of the progressive aging of the population. Their diagnosis is often a challenge for clinicians and, even in the best cases, only a possible or probable diagnosis can be reached. Molecular neuroimaging techniques can be very useful in dementia patients, especially for obtaining a diagnosis in the early stage of disease. The most diffuse and widely available nuclear medicine method for neurological studies is F-fluoro-deoxy-glucose (F-FDG)-PET, which allows the quantification of glucose gray matter metabolism and helps visualize typical, adequately specific, patterns for many kinds of degenerative dementia, not only for the well-known and well-studied Alzheimer's disease. This paper aims to describe the clinical and F-FDG-PET profiles of the principal non-Alzheimer type of degenerative dementias.

Aim To assess the predictive value of fluorine-18-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) in early assessing response during neo-adjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer. Materials and methods A systematic review was performed by search of MEDLINE Library for the following terms: "rectal carcinoma OR rectal cancer", "predictive OR prediction OR response assessment OR response OR assessment", "early OR ad interim ", "therapy", "FDG OR 18 F-FDG", "PET OR PET/CT". Articles performed by the use of stand-alone PET scanners were excluded. Results 10 studies met the inclusion criteria, including 302 patients. PET/CT demonstrated a good early predictive value in the global cohort (mean sensitivity = 79%; mean specificity = 78%). SUV and its percentage decrease (response index = RI) were calculated in all studies. A higher accuracy was demonstrated for RI (mean sensitivity = 82%; pooled specificity = 85%) with a mean cut-off of 42%. The mean time point to perform PET scan during CRT resulted to be at 1.85 weeks. Some PET parameters resulted to be both predictive and not statistical predictive of response, maybe due to the small population and few studies bias. Conclusion PET showed high accuracy in early prediction response during preoperative CRT, increased with the use of RI as parameter. In the era of tailored treatment, the precocious assessment of non-responder patients allows modification of the subsequent strategy especially the timing and the type of surgical approach.

AIM: The aim of our retrospective study was to assess the usefulness of F-FDG PET/CT in the restaging of clear cell renal cell carcinoma (RCC) patients. PATIENTS AND METHODS: Sixty-nine patients (median age = 62 years; range = 36-86 years) affected by clear cell RCC (TNM at staging: T1, 42 patients; T2, 13 patients; T3, 11 patients; T4, 3 patients; Fuhrman grade: G2, 47 patients; G3, 20 patients; G4, 2 patients) underwent whole-body F-FDG PET/CT to restage the disease after nephrectomy for clinical or radiological suspicion of metastases. Areas of abnormal uptake at PET/CT were classified, taking the liver uptake as reference, as follows: 1 = faint uptake, lower than liver; 2 = moderate uptake, equal to liver; and 3 = high uptake, higher than liver. Validation of F-FDG PET/CT results was established by (1) biopsy (23 patients) and (2) other imaging modalities (addressed BS; c.e.CT; MRI; F-fluoride PET/CT; subsequent F-FDG PET/CT), and/or clinical and radiological follow-up of 12 months (46 patients). RESULTS: F-FDG PET/CT was positive in 42 patients and negative in 27 patients. Sixteen patients presented single lesions and 26 patients presented multiple localizations of the disease. On a patient basis, 40 patients resulted true positive, 2 patient false positive, 23 patients true negative, and 4 patients false negative. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 90%, 92%, 91%, 95%, and 85%, respectively. On a lesion basis, PET/CT detected 114 areas of abnormal uptake in 42 positive patients of which 112 resulted to be true positive. FDG uptake of the true positive lesions resulted to be high in 83 cases, moderate in 17 lesions, and finally faint in 12 lesions. CONCLUSIONS: F-FDG PET/CT demonstrated a good sensitivity in the restaging of clear cell RCC. Most of the lesions showed intense activity. According to our results, it seems that the use of F-FDG PET/CT in the restaging of RCC is feasible because the number of false-negative cases is limited.

Epithelial ovarian carcinoma is a major form of cancer affecting women in the western world. The silent nature of this disease results in late presentation at an advanced stage in many patients. It is therefore important to assess the role of imaging techniques in the management of these patients. This article presents a review of the literature on the role of (18)F-FDG-PET/CT in the different stages of management of epithelial ovarian cancer. Moreover, a comparison with other imaging techniques has been made and the relationship between (18)F-PET/CT and the assay of serum CA-125 levels has been discussed.

The aim of this study was to examine a homogeneous, consecutive recent series of patients who underwent reoperation on the thyroid bed to assess the incidence of the complications commonly correlated with resurgery. We reviewed clinical charts of 233 patients who underwent resurgery taken from a total of 4,752 patients previously operated on for benign and malignant thyroid diseases from 2006 to 2010 by the same surgical team. We evaluated the incidence of postoperative hemorrhage, hypoparathyroidism, and recurrent laryngeal nerve (RLN) palsy. Analyses were done separately in relation to the type of the type of resurgery adopted: (A) monolateral completion; (B) bilateral completion, after monolateral (B1) or bilateral prior surgery (B2); and (C) lymph node dissection. We also separately analyzed patients according to their final histological diagnosis of benign or malignant disease. Regarding hemorrhage, 6/233 patients (2.5 %) underwent surgical revision of the thyroid within 12 h for postoperative hemorrhage. They included 2 (1.5 %) of the 129 monolateral reoperations (A), 3 (4 %) of the 74 bilateral reoperations (B), and 1 (3.3 %) of the 30 central dissections for nodal relapse (C). Transient and definitive postoperative hypoparathyroidism was recorded in 78 (36.4 %) and 7 (3.3 %) of the 214 eligible patients. Transient RLN palsy occurred in 21 RLNs at risk (7 %) and definitive RLN palsy in 5 (1.7 %). Elective total thyroidectomy cannot always be supported as an effective policy for preventing recurrences in patients with a single, benign node: lobectomy, preferably with extemporaneous histological examination, unquestionably represents the best minimal approach to thyroid resection.

PURPOSE FDG PET/CT has a recognized high predictive power to assess the response to neoadjuvant chemoradiation therapy (CRT) in patients affected by locally advanced rectal cancer (LARC), but a relatively high number of false-positive findings decrease its specificity: with the aim to solve this problem, a new method of imaging analysis is here proposed. METHODS The new method here described, named Biological target volume (BTV) Overlapping Segmentation System (BOSS), has been applied on 24 consecutive patients with LARC that were all previously classified as nonresponders to CRT by means of the response index criterion that is adopted in our center. The BOSS method is based on the quantification of the amount of superimposition between pretreatment and posttreatment BTV. All BTVpre was down using a threshold of 60% of SUVmax in the tumor (BTV60). The results (overlap volumes and percentage of overlap volumes) were then matched up with postoperative pathology classified by the Mandard's tumor regression grade (TRG) system. RESULTS Eleven patients were classified as responders (TRG1-2) and 13 as nonresponders (TRG 3-5). Among all the results obtained by BOSS method, only the percentage of overlap volume data between BTV60 and BTVpost (%Over_60) was able to correctly distinguish between responders and nonresponders. In our experience, a cutoff of 56% on the %Over_60 provided the best results in terms of true negative (11 cases), true positive (12 cases), false negative (1 case), and false positive (none). CONCLUSIONS This new method, we developed, appears able to unmask the false-positive cases, improving the specificity of FDG PET/CT to predict the response to CRT patients with LARC.

PURPOSE: To evaluate if the detection rate (DR) of (18)F-choline (18F-CH) PET/CT is influenced by androgen-deprivation therapy (ADT) in patients with prostate cancer (PC) already treated with radical intent and presenting biochemical relapse. MATERIALS AND METHODS: We have retrospectively evaluated (18)F-CH PET/CT scans of 325 consecutive PC patients enrolled in the period November 2009 to December 2012 previously treated with radical intent and referred to our centre to perform (18)F-CH PET/CT for biochemical relapse. Two different groups of patients were evaluated. group A included the whole sample of 325 patients (mean age 70 years, range: 49-86) who presented trigger PSA between 0.1 and 80 ng/ml (mean 5.5 ng/ml), and group B included 187 patients (mean age 70 years, range 49-86) with medium-low levels of trigger PSA ranging between 0.5 and 5 ng/ml (mean PSA 2.1 ng/ml); group B was chosen in order to obtain a more homogeneous group of patients in terms of PSA values also excluding both very low and very high PSA levels avoiding the "a priori" higher probability of negative or positive PET scan, respectively. At the time of examination, 139 patients from group A and 72 patients from group B were under ADT: these patients were considered to be hormone-resistant PC patients because from their oncologic history (>18 months) an increase of PSA levels emerged despite the ongoing ADT. The relationship between (18)F-CH PET/CT findings and possible clinical predictors was investigated using both univariate and multivariate binary logistic regression analyses, including trigger PSA and ADT. RESULTS: Considering the whole population, overall DR of (18)F-CH PET was 58.2 % (189/325 patients). In the whole sample of patients (group A), both at the univariate and multivariate logistic regression analysis, trigger PSA and ADT were significantly correlated with the DR of (18)F-CH PET (p

This review article is focused on the role of FDG-PET/CT in visualizing atherosclerosis and on the relevance of inflammatory cells such as macrophages and T-lymphocytes in the formation of the atherosclerotic plaque. The vulnerability of the inflammatory plaque and the risk derived from the provocation of cardio- and cerebrovascular incidents independently from the presence of stenotic vessels are discussed as well as the evolution toward calcified plaque. The important role of FDG-PET/CT in early diagnosis of inflammatory plaque is discussed in both animal studies and in clinical setting. The possibility of curing inflammatory plaques, type of drugs, and the possibility of monitoring the anti-inflammatory treatment by FDG-PET/CT are also discussed.

Purpose The aims of the study were (a) to evaluate the diagnostic role, by means of positive detection rate (PDR), of 18F-choline (CH) positron emission tomography (PET)/CT in patients with prostate cancer treated with radiotherapy, with curative intent, and suspicion of relapse during follow-up, (b) to correlate the PDR with trigger prostate-specific antigen (PSA), (c) to investigate the possible influence of androgen deprivation therapy (ADT) at the time of scan on PDR and (d) to assess distribution of metastatic spread.

The aim of this study was to correlate qualitative visual response and various PET quantification factors with the tumour regression grade (TRG) classification of pathological response to neoadjuvant chemoradiotherapy (CRT) proposed by Mandard.Included in this retrospective study were 69 consecutive patients with locally advanced rectal cancer (LARC). FDG PET/CT scans were performed at staging and after CRT (mean 6.7 weeks). Tumour SUVmax and its related arithmetic and percentage decrease (response index, RI) were calculated. Qualitative analysis was performed by visual response assessment (VRA), PERCIST 1.0 and response cut-off classification based on a new definition of residual disease. Metabolic tumour volume (MTV) was calculated using a 40 % SUVmax threshold, and the total lesion glycolysis (TLG) both before and after CRT and their arithmetic and percentage change were also calculated. We split the patients into responders (TRG 1 or 2) and nonresponders (TRG 3-5).SUVmax MTV and TLG after CRT, RI, ΔMTV% and ΔTLG% parameters were significantly correlated with pathological treatment response (p0.01) with a ROC curve cut-off values of 5.1, 2.1 cm(3), 23.4 cm(3), 61.8 %, 81.4 % and 94.2 %, respectively. SUVmax after CRT had the highest ROC AUC (0.846), with a sensitivity of 86 % and a specificity of 80 %. VRA and response cut-off classification were also significantly predictive of TRG response (VRA with the best accuracy: sensitivity 86 % and specificity 55 %). In contrast, assessment using PERCIST was not significantly correlated with TRG.FDG PET/CT can accurately stratify patients with LARC preoperatively, independently of the method chosen to interpret the images. Among many PET parameters, some of which are not immediately obtainable, the most commonly used in clinical practice (SUVmax after CRT and VRA) showed the best accuracy in predicting TRG.

Noncutaneous melanoma is a rare entity for which there is still no agreement about management. The rarity of this disease has resulted in a lack of significant investigation and insufficient opportunity to evaluate the epidemiologic features, risk factors, and the most useful diagnostic and therapeutic approaches. Noncutaneous melanomas are characterized by poor prognosis, and the diagnosis is usually delayed because of their unusual locations and lack of physician awareness. This review focuses principally on ocular melanoma, the most frequent noncutaneous melanoma, for which each aspect of the disease is described. The potential utility of nuclear medicine procedures is also considered.

A 75-year-old man presented with significant weight loss, persistent cough, single episode of frontotemporal pulsatile headache, and leg weakness. A paraneoplastic syndrome was suspected, and F-FDG PET/CT was performed. Diffuse, moderate-to-intense tracer symmetrical uptake of many large and medium arteries was unexpectedly noted. The peculiarity of this case is the extensive involvement of both large and medium head and neck and extremity vessels, whereas the aorta was relatively spared.

In recent years, preoperative imaging has become essential in the evaluation of sporadic primary hyperparathyroidism (HPT) for selecting good candidates for minimally invasive HPT. Its role in patients with secondary/tertiary HPT is under investigation. Imaging is mandatory before reoperative parathyroid surgery for persistent or recurrent HPT, whatever the setting. This review provides detailed information regarding the nuclear imaging methods (dual phase, subtraction), the role of SPECT and SPECT/CT, and the clinical results of parathyroid scintigraphy in different clinical situations.

In this paper, a new methodological approach to using PET information in radiotherapy treatment planning has been discussed. Computed tomography (CT) represents the primary modality to plan personalized radiation treatment, because it provides the basic electron density map for correct dose calculation. If PET scanning is also performed it is typically coregistered with the CT study. This operation can be executed automatically by a hybrid PET/CT scanner or, if the PET and CT imaging sets have been acquired through different equipment, by a dedicated module of the radiotherapy treatment planning system. Both approaches have some disadvantages: in the first case, the bore of a PET/CT system generally used in clinical practice often does not allow the use of certain bulky devices for patient immobilization in radiotherapy, whereas in the second case the result could be affected by limitations in window/level visualization of two different image modalities, and the displayed PET volumes can appear not to be related to the actual uptake into the patient. To overcome these problems, at our centre a specific procedure has been studied and tested in 30 patients, allowing good results of precision in the target contouring to be obtained. The process consists of segmentation of the biological target volume by a dedicated PET/CT console and its export to a dedicated radiotherapy system, where an image registration between the CT images acquired by the PET/CT scanner and a large-bore CT is performed. The planning target volume is contoured only on the large-bore CT and is used for virtual simulation, to individuate permanent skin markers on the patient.

Objectives Breast cancer is the second cause of death in women in Europe and North America. The mortality of this disease can be reduced with effective therapy and regular follow up to detect early recurrence. Tumor markers are sensitive in detecting recurrent or residual disease but imaging is required to customize the therapeutic option. Rising tumor markers and negative conventional imaging (US, X-mammography, CT and MR) poses a management problem. Our aim is to assess the role of 18F-FDG-PET/CT in the management of post-therapy patients with rising markers but negative conventional imaging. Materials and methods In the period from January 2008 to September 2009, 89 female patients with breast cancer who developed post-therapy rising markers (serum Ca 15-3 levels = 64.8 ± 16.3 U/mL) but negative clinical examination and conventional imaging were investigated with 18F-FDG-PET/CT. Results Tumor deposits were detected in 40/89 patients in chest wall, internal mammary nodes, lungs, liver and skeleton. The mean SUVmax value calculated in these lesions was 6.6 ± 1.7 (range 3.1–12.8). In 23/40 patients solitary small lesion were amenable to radical therapy. In 7 out of these 23 patients a complete disease remission lasting more than 1 year was observed. Conclusions 18F-FDG-PET/CT may have a potential role in asymptomatic patients with rising markers and negative conventional imaging. Our findings agree with other studies in promoting regular investigations such as tumor markers and 18F-FDG-PET/CT rather than awaiting the developments of physical symptoms as suggested by current guidelines since the timely detection of early recurrence may have a major impact on therapy and survival.

In the present review article we presented the major technical innovations regarding the diagnosis of NET with PET/CT 68Ga-DOTA-peptides compounds over conventional radiologic and scintigraphic imaging, discussing both the different types of radiopharmaceuticals commercially available, trying to making a comparison on the possible advantages and drawbacks of these radiopharmaceuticals, and providing also some technical recommendations to the radiologists and nuclear physicians for using these new methodology in an appropriate manner in the clinical setting.

This short review aims at summarizing the available data pertaining to the usefulness of F-18 FDG PET/CT in rectal cancer. It is specifically focused on the emerging role of F-18 FDG PET/CT in assessing the response to neoadjuvant combined radiochemotherapy in locally advanced rectal cancer. It also probes the possibility of finding standardized PET/CT parameters that are capable of differentiating responders from nonresponders in whom therapeutic approach could be modified.

This review describes the pathogenic mechanisms of blood pressure (BP) regulation and long-term control in thyroid disorders. Variations from the euthyroid status affect virtually all physiological systems but the effects on the cardiovascular system are particularly pronounced. Thyroid disorders induce several hemodynamic changes leading to elevated BP as a consequence of their interaction with endothelial function, vascular reactivity, renal hemodynamic and renin-angiotensin system. However, in thyroid disorders, the regulation of BP and the development and maintenance of variable forms of arterial hypertension (HT) are different. Hyperthyroidism results in an increased endothelium-dependent responsiveness secondary to the shear stress induced by the hyperdynamic circulation, and contributes to reduce vascular resistance. Conversely, hypothyroidism is accompanied by a marked decrease in sensitivity to sympathetic agonists with an increase of peripheral vascular resistance and arterial stiffness. Furthermore in animal models, hypothyroidism reduces the endothelium-dependent and nitric oxide-dependent vasodilatation. HT due to thyroid disorders is usually reversible with achievement of euthyroidism, but in some cases pharmacological treatment for BP control is required. In hyperthyroidism, β-blockers are the first-choice treatment to control BP but when they are contraindicated or not tolerated, ACE-inhibitors or calcium-channel blockers (CCB) are recommended. Hypothyroidism is a typical low rennin HT form showing a better antihypertensive response to CCB and diuretics; indeed in hypothyroidism a low-sodium diet seems further to improve BP control. Randomized clinical trials to compare the efficacy on BP control of the antihypertensive treatment in thyroid disorders are needed.

Fluorine-18-fluorodeoxyglucose PET/CT is an accurate tool for predicting the response to preoperative chemoradiotherapy in locally advanced rectal cancer patients. The need for standardization has contributed to the development of various criteria for harmonizing PET response. The novel proposed set of criteria called PET Residual Disease in Solid Tumor (PREDIST) seems to better distinguish between responder and nonresponder patients to chemoradiotherapy compared with the PET Response Criteria in Solid Tumors criteria.

State of the art point-spread function (PSF) corrections implemented in positron emission tomography/computed tomography (PET/CT) reconstruction improved image quality and diagnostic performance but caused an increase in the standardized uptake value (SUV) compared to a conventional OSEM reconstruction system. The EANM suggested one produce two reconstructions, one optimised for maximum lesion detection and one for semi-quantitative analysis. In this work we investigated an alternative methodology, using a single reconstruction data set together with a post-reconstruction algorithm for SUV harmonization. Data acquisition was performed on a Siemens Biograph mCT system equipped with lutetium oxyorthosilicat crystals, PSF and time-of-flight algorithms and on a General Electric Discovery STE system equipped with BGO crystals. Both a EANM double reconstruction method and a dedicated post-reconstruction algorithm (marketed as EQ-filter) were tested to harmonize the quantitative values of the two PET/CT scanners. For phantom measurements we used a NEMA IQ phantom and a Jaszczak cylindrical phantom equipped with small spheres (lesion to background ratios of 8:1 and 4:1). Several different reconstruction settings were tested in order to provide a general methodology. Data obtained by phantom measurements were validated on seven oncologic patients who performed a one-bed extra acquisition on a different scanner. The evaluation regarded 39 small lesions (diameters: 0.3-2.6 cm) and was performed by two experienced nuclear medicine physicians. The SUV recoveries measured with the PSF reconstruction exceeded those obtained by the OSEM reconstruction with deviations ranging from 16% to 150%. These discrepancies resulted below 7% applying the optimized value of the EQ.filter or the double-reconstruction methods. For each reconstruction setting the optimal value of the EQ.filter was identified in order to minimize these discrepancies. Patient data, analyzed by Wilcoxon statistical test, confirmed and validated phantom measurements. EQ.filter can harmonize SUV values between different PET/CT scanners using a single reconstruction optimized to maximum lesion detectability. In this way, the second reconstruction proposed by EANM/EARL is avoided.

The introduction and successful implementation of minimally invasive radio-guided parathyroidectomy (MIRP) has revolutionized the surgical approach to remove parathyroid adenomas. A prerequisite for such success is an accurate localization of the offending adenoma. To achieve this goal, a multimodality approach is commonly employed using a combination of anatomical and functional imaging. Of the anatomical cross-sectional techniques, ultrasonography is the most widely available but is operator-dependent and has reduced sensitivity, specially in the presence of thyroid nodules. Similarly, computed tomography and magnetic resonance imaging have low sensitivities but provide value in detecting retrotracheal, retro-oesophageal and mediastinal adenomas. Functional imaging with ⁹⁹(m)Tc-Sestamibi is currently the most vital imaging procedure in this respect with variable protocols including dual-phase and dual isotope imaging. The sensitivity and specificity can improve by acquiring in single photon emission tomography (SPECT) mode and using co-registration with low dose CT to provide anatomical data (SPECT/CT). The current recommended approach is the combination of functional imaging with ⁹⁹(m)Tc-Sestamibi and high-resolution ultrasound (US), supplemented with intraoperative gamma probe in certain cases and quick persurgical measurement of parathyroid hormone. This review aims to explore the utility of various imaging modalities, alone and in combination, in detecting parathyroid adenoma and facilitating the current approach of MIRP.

Objectives Potential causes of cryptogenic cerebrovascular (CV) events are patent foramen ovale (PFO) and hyper homocysteinemia (H-Hcys), this latter a well-established risk factor for thrombosis particularly in the presence of mutation for the methylenetetrahydrofolate reductase (MTHFR) gene. This study investigated if in uncomplicated hypertensive subjects (HTs) with isolated PFO and H-Hcys, a different MTHFR polymorphism pattern for C667 → T gene mutation could influence PFO management and to reduce the CV risk. Methods In thirty-two HTs aged 55.6 ± 14.4 years, PFO was diagnosed by echocardiography. MTHFR genotype was evaluated by a multiplex polymerase chain reaction with reverse line blot hybridization assay. In relation to the T allele distribution, HTs were divided in normal (CC), heterozygote (CT) and homozygote (TT) for the MTHFR genotype. All subjects received a supplementation of oral folate (5 mg daily) and were evaluated yearly for 2 years. Analysis of variance for repeated measures (ANOVA) was used to compare changes of Hcys at baseline and at the end of follow-up and differences between continuous variables were evaluated in the three MTHFR groups with the Tukey's post hoc test after adjustment for confounders. Results At the follow-up, Hcys levels significantly normalized from baseline both in TT (38.1 ± 6.7 vs. 15 ± 3.6, p

La diagnostica del femocromocitoma e dei paragangliomi, oltre a prevedere un’iniziale valutazione biochimica che accerti le caratteristiche secretive del tumore, consta dell’applicazione di metodiche di imaging integrato, morfologico e funzionale, al fine della localizzazione del tumore stesso. Nella maggior parte dei casi l’imaging integrato risulta sinergico ai fini di ottenere una diagnosi corretta e un’accurata valutazione dell’estensione della malattia. Abitualmente l’imaging morfologico, principalmente tomografia assiale computerizzata (TAC) e risonanza magnetica nucleare (RMN), viene utilizzato nella prima fase dell’iter diagnostico di localizzazione e consente di valutare l’anatomia della lesione primitiva, mentre quello funzionale medico-nucleare entra in gioco in un secondo tempo per confermare la diagnosi, caratterizzare la lesione e stadiare la malattia. A questo scopo la medicina nucleare offre numerosi traccianti radiomarcati idonei per esami ad emissione di singolo fotone (scansione whole-body e SPECT) e per indagini ad emissione di positroni /doppio fotone (PET). La presente review, alla luce delle rilevanti innovazioni avvenute negli ultimi anni in termini di tecnologia avanzata, si pone il fine di descrivere le metodiche che rappresentano attualmente lo stato dell’arte nella diagnostica di queste patologie, proponendo anche delle flowchart diagnostiche.

The most common malignancy affecting the liver is metastasis from a wide variety of tumors, particularly those of gastrointestinal origin. Successful surgical removal of a solitary liver metastasis may significantly extend survival and optimal preoperative assessment in this regard is a mandatory prerequisite for proper patient selection. The addition of positron emission tomography/computed tomography (PET/CT) to other more conventional imaging procedures (e.g., ultrasound (US), CT, and magnetic resonance) has the potential to greatly improve the selection process by the combination of high-resolution anatomy afforded by CT directly combined with the functional scintigraphic map of intra- and extrahepatic lesions depicted by 2-deoxy-2-[F-18]fluoro-D-glucose (FDG)-PET. In this study, we assess the additional value of PET/CT in the management strategy of patients with solitary liver metastasis from colorectal and other cancers identified by conventional imaging methods.We evaluated 43 consecutive patients (17 males, 26 females, mean age 53 +/- 6 years) with known solitary liver metastasis. This sample consisted of 18 patients with colorectal cancer, 15 with nonsmall cell lung cancer, six with breast carcinoma, and four ovarian cancers. In addition to contrast-enhanced CT and US, all patients were studied with FDG-PET/CT before surgery. PET/CT was performed within 3 weeks of the initial diagnosis and the scans were read by two experienced radiologists/nuclear medicine specialists blinded to the clinical data. A final diagnosis was obtained at surgery in 31 patients, by fine needle biopsy in five, and long-term clinical, biochemical, and follow-up imaging in seven patients.In 12 out of 43 patients (28%), PET/CT resulted in restaging disease and a change in therapy. Twenty-two of 31 patients with confirmed solitary liver lesions (71%) were disease-free, eight of 31 (26%) developed a new recurrence, and one of 31 (3%) died from disease progression over a 17 +/- 6-month follow-up interval. Nine of 12 patients (75%) with multiple metastases demonstrated by FDG-PET/CT were alive with disease and three of 12 (25%) deceased due to disease progression (p0.01) over a 17 +/- 6-month follow-up interval.The addition of FDG-PET/CT to the routine assessment of patients with liver metastasis has a significant impact on disease staging and selection of suitable candidates for solitary liver metastasis resection and outcome.

AIM To evaluate clinical efficacy of a dual-time acquisition protocol, which included 4 and 20/24-h imaging with antigranulocyte antibody scintigraphy (LeukoScan) combined with semiquantitative analysis in the diagnosis of infection in painful hip prosthesis. METHODS Sixty-seven consecutive patients with hip prosthesis were enrolled in this research project: 35 females, 32 males, mean age of 56.3 years. All patients had clinical and biochemical suspicious of infection. Each prosthesis had been implanted 3 months to 12 years before enrollment in this study. Twenty-four patients were on antibiotic therapy at the time of scintigraphy. Seven patients had bilateral hip prosthesis, one painful and the other painless: the seven painless prostheses were considered controls. LeukoScan examination was performed both at early (4 h) and delayed (20/24 h) times. The scintigraphic data were assessed both by visual and semiquantitative methods by three experienced nuclear medicine physicians blinded to clinical, laboratory and radiographic results. The uptake was graded visually by a 4-point scale: intense=3, moderate=2, mild=1 and absent=0. The semiquantitative analysis was obtained by a region of interest (ROI) analysis used in the anterior views to measure the ratio between the mean radioactivity in the prosthesis and the background radioactivity in the early and delayed images. An increase in the intensity of uptake of at least one scale-step at visual analysis and 20% at semiquantitative ROI analysis at the dual-time (early vs. delayed) LeukoScan was considered consistent with infection, whereas a stable or decreasing pattern was judged a negative result. Three-phase 99mTc-hydroxymethane diphosphonate bone scan was also performed routinely. Final diagnosis was determined at surgery and/or long-term clinical and imaging follow-up. RESULTS At visual analysis, sensitivity for both early and delayed imaging was 94%, whereas specificity was 71% for early imaging and 83% for early and delayed imaging approach. At semiquantitative ROI analysis, sensitivity remained 94%, whereas specificity rose slightly to 73% for early imaging and to 90% for early and delayed imaging combined. Of note, four false-positive early scans were diagnosed correctly as negative on delayed imaging showing a decreasing pattern in uptake intensity. Sensitivity and specificity were similar whether patients were on or off antibiotic therapy. CONCLUSION Our data show that early imaging LeukoScan is highly sensitive in evaluating septic prosthesis, but it is not optimally specific. Although the dual-time LeukoScan is capable of significantly increasing specificity for detecting infection. The semiquantitative ROI analysis further increased the specificity. Concomitant antibiotic treatment did not seem to influence the diagnostic efficacy of LeukoScan scintigraphy in detecting infected hip prosthesis.

In parathyroid disease, classical scintigraphic techniques remain the first choice for localizing hyperfunctional parathyroid glands in primary known hyperparathyroidism and in case of secondary, tertiary, and recurrent hyperparathyroidism. When classical scintigraphic techniques are not diagnostic, however, (11)C-methionine seems to offer a good imaging alternative.

A 76-year-old woman was referred to our centre to perform (18)F-FDG PET/CT with the clinical suspicion of vasculitis. Whole body PET was negative for vasculitis but it depicted moderate hypermetabolism in several lymph nodes of the mediastinum and intense uptake of the tracer in the parotid glands. Since the patient referred skin lesion on both legs a particular acquisition of the lower extremities was performed which showed diffuse uptake on the perimalleolar region of both legs. On the basis of the PET/CT findings that were suggestive for sarcoidosis the patient performed bronchoalveolar lavage (BAL) and biopsy of a mediastinal lymph node which confirmed the suspicion of sarcoidosis.

We report here a case of a paediatric hyperthyroidism due to a micro-macro-follicular thyroid adenoma in the presence of heterozygous point mutation of TSH receptor (TSHr). We describe the case from the initial diagnosis, through laboratoristic examinations and imaging techniques, until the radical surgical treatment made by a mini-cervicotomic videoassisted technique. We also explained the genetic work-up from peripheral blood and thyroid adenoma tissue.

A 67-year-old man, previously operated for a pancreatic neuroendocrine tumor (NET), had progressive increase of serum chromogranin A during follow-up. Sequential 68Ga-DOTA-NOC and F-18 FDG PET/CT were performed. 68Ga-DOTA-NOC imaging was negative, whereas F-18 FDG PET/CT showed 2 hypermetabolic hepatic lesions demonstrated at CT-guided biopsy as metastatic deposits from a high-grade (G3) aggressive NET. Despite the large consensus of SPECT or PET with radiolabeled somatostatin analogs as first choice in functional imaging for detecting NETs metastasis, F-18 FDG may occasionally be the right tracer to provide accurate diagnostic and prognostic information in aggressive G3 NET.

In the present review we reported the value of 18F-fluorodeoxyglucose (FDG) PET/CT in face of uterine cancer, in terms of sensitivity, specificity and accuracy. Moreover, we made a comparison with the other imaging techniques currently used to evacuate these tumors including contrast-enhanced CT, contrast enhanced-MRI and transvaginal ultrasonography. FDG PET/CT has been reported to be of particular value in detecting occult metastatic lesions, in prediction of response to treatment and as a pro-gnostic factor.

Purpose: This study evaluates the use of sequential 124I PET/CT for predicting absorbed doses to metastatic lesions in patients with differentiated thyroid cancer undergoing 131I therapy. Methods: From July 2011 until July 2013, 30 patients with metastatic differentiated thyroid cancer were enrolled. Each participant underwent PET/CT at 4, 24, 48, and 72 hours with 74 MBq of 124I. Blood samples and whole-body exposure measurements were obtained to calculate blood and red marrow doses. Activity concentrations and lesion volumes obtained from PET/CT were used to evaluate tumor doses with medical internal radiation dose formalism and spheres modeling. Mean administered 131I therapeutic dose was 5994 MBq (range, 1953–11,455 MBq). Results: 124I PET/CT demonstrated all lesions detected by posttherapy 131I whole-body scans. Mean dose rates for blood, red marrow, and lesions were as follows: 0.07 ± 0.02 mGy/MBq, 0.05 ± 0.02 mGy/MBq, and 46.5 ± 117 mGy/MBq, respectively. Despite the high level of thyroid-stimulating hormone and CT detectable lesions, 15 of 30 patients did not show any abnormal 124I uptake. Conclusions: The quantitative value of 124I PET/CT allows simple and accurate evaluation of lesion dosimetry following medical internal radiation dose formalism. Negative 124I PET/CT predicts absence of iodine avidity, potentially allowing avoidance of therapeutically ineffective 131I administration.

Purpose. (1) To evaluate a new acquisition protocol of18F-choline (FCH) PET/CT for prostate cancer patients (PC), (2) to review acquisition18F-choline PET/CT methodology, and (3) to propose a standardized acquisition protocol on FCH PET/CT in PC patients.Materials. 100 consecutive PC patients (mean age 70.5 years, mean PSA 21.35 ng/mL) were prospectively evaluated. New protocol consisted of an early scan of the pelvis immediately after the injection of the tracer (1 bed position of 4 min) followed by a whole body scan at one 1 hour. Early and 1 hour images were compared for interfering activity and pathologic findings.Results. The overall detection rate of FCH PET/CT was 64%. The early static images of the pelvis showed absence of radioactive urine in ureters, bladder, or urethra which allowed a clean evaluation of the prostatic fossae. Uptake in the prostatic region was better visualized in the early phase in 26% (7/30) of cases. Other pelvic pathologic findings (bone and lymph nodes) were visualized in both early and late images.Conclusion. Early18F-choline images improve visualization of abnormal uptake in prostate fossae. All pathologic pelvic deposits (prostate, lymph nodes, and bone) were visualized in both early and late images.

This review article is focused on the role of FDG PET/CT in diagnosing and characterizing hepatic incidentalomas. A large variety of unsuspected lesions can be detected in the liver both with ultrasound and CT performed for other reasons; the prevalence of liver incidentalomas increases in patients with chronic liver disease or preexisting oncologic history. The major challenge is to discriminate benign from malignant lesions. There is a large body of literature indicating that FDG PET/CT is a useful tool to this purpose even if it is unspecific (ie, it cannot differentiate a primary tumor from a secondary lesion). Occasionally, FDG PET/CT can be useful for biopsy guidance.

PURPOSE The aim of this study was to correlate PERCIST criteria and a new criterion developed in our center that we named PREDIST (PET Residual Disease in Solid Tumor) with tumor regression grade (TRG) classification of pathologic response to neoadjuvant chemoradiotherapy (CRT) in patients affected by rectal cancer. METHODS Seventy-three consecutive patients affected by locally advanced rectal cancer (LARC) were retrospectively included. FDG-PET/CT scans were performed at staging time and after the end of CRT (mean time 6.5 weeks). The analysis was performed by PERCIST criteria 1.0 and PREDIST criteria based on a new definition of residual disease. We split the TRG system into responders (TRG1-2) and nonresponders (TRG3-5). Pearson chi-square analysis by cross-tabulations was performed. RESULTS PREDIST classification was statistically predictive of TRG response (P = 0.004, sensitivity 81.8% and specificity 54.9%). On the contrary, PERCIST criteria was not statistically correlated to TRG (P = 0.128) caused by a very low specificity (9.8%). CONCLUSIONS FDG-PET/CT scan is an accurate tool to predict preoperatively the response to CRT in LARC patients. The novel proposed criterion (PREDIST) seems to be helpful to discriminate responder by nonresponder patients.

The aims of the study were (a) to evaluate the diagnostic role, by means of positive detection rate (PDR), of ¹⁸F-choline (CH) positron emission tomography (PET)/CT in patients with prostate cancer treated with radiotherapy, with curative intent, and suspicion of relapse during follow-up, (b) to correlate the PDR with trigger prostate-specific antigen (PSA), (c) to investigate the possible influence of androgen deprivation therapy (ADT) at the time of scan on PDR and (d) to assess distribution of metastatic spread.¹⁸F-CH PET/CT exams from 46 consecutive patients (mean age 71.3 years, range 51-84 years) with prostate cancer (mean Gleason score 6.4, range 5-8) previously treated by definitive radiotherapy and with suspicion of relapse with negative or inconclusive conventional imaging were retrospectively evaluated. Of the 46 patients, 12 were treated with brachytherapy and 34 with external beam radiation therapy. Twenty-three patients were under ADT at the time of the examination. Trigger PSA was measured within 1 month before the exam (mean value 6.5 ng/ml, range 1.1-49.4 ng/ml). Patients were subdivided into four groups according to their PSA level: 1.0PSA ≤ 2.0 ng/ml (11 patients), 2.0PSA ≤ 4.0 ng/ml (16 patients), 4.0PSA ≤ 6.0 ng/ml (9 patients) and PSA6.0 ng/ml (10 patients). Correlation between ADT and PDR was investigated as well as between PSA and distribution of metastatic spread.The overall PDR of ¹⁸F-CH PET/CT was 80.4% (37/46 patients), increasing with the increase of trigger PSA. PDR of ¹⁸F-CH PET/CT is not influenced by ADT (p = 0.710) even if PET performed under ADT demonstrated an overall higher PDR (82.6%). The majority of the patients (59%, 22/37 patients) showed local relapse only, confined to the prostatic bed; 22% of the PET/CT-positive patients (8/37 patients) showed distant relapse only (bone localizations in all of them), while the remaining 19% (7/37 patients) showed both local and distant (lymph node and bone) spread.¹⁸F-CH PET/CT showed a high overall detection rate (80%), proportional to the trigger PSA (both for local and distant relapse) not influenced by ADT. ¹⁸F-CH PET/CT is proposed as a first-line imaging procedure in restaging prostate cancer patients primarily treated with radiotherapy.

The aim of this study was to evaluate the efficacy of ¹⁸F-choline PET/CT (18FCH-PET/CT) in restaging patients previously treated by radical prostatectomy for a prostate cancer, presenting with biochemical relapse during follow-up (FU).Three hundred thirty-one patients referred to us from January 2009 to April 2011 to perform 18FCH PET/CT were evaluated: 233 of them (mean age 69.7 years) met the inclusion criteria of the study: (1) biochemical relapse after radical prostatectomy (trigger PSA0.2 ng/mL) (n=224) and (2) high risk for relapse (elevated Gleason score≥8) in spite PSA0.1 ng/mL during FU (n=9). Trigger PSA was available for all patients (mean 8 ng/mL) and in 44 of them also PSA kinetic (PSA velocity-PSAvel; PSA doubling time-PSAdt). Correlation between 18FCH PET/CT detection rate and trigger PSA, PSAvel, PSAdt, and tumoral spread distribution were evaluated by univariate and multivariate analysis. Subsequent minimum FU was 1 year (mean 26 months, range 12-40).Overall detection rate of 18FCH PET/CT was 54%, which significantly increased when the trigger PSA increases (P0.001). PET-positive patients presented a "fast" PSA kinetic (mean PSAdt=6 months and mean PSAvel=9.3 ng/mL/yr), while PET-negative patients presented a "slow" PSA kinetic (mean PSAdt=15.4 months and mean PSAvel=0.9 ng/mL/yr). Disease relapse was local in 17% of cases, distant in 66%, and combined in 17%.Overall 18FCH PET/CT detection rate was 54% (ie, similar to that reported in literature with ¹¹C-choline), which increases with the increase in trigger PSA: this condition was particularly true in patients with accelerated PSA kinetic. In about 20% of patients, 18FCH PET/CT demonstrated local relapses early enough to offer locoregional radiation therapy.

Purpose This study aimed to describe 99mTc-labeled RBC scintigraphy as a diagnostic method for orbital cavernous hemangiomas and to evaluate this diagnostic tool according to surgical outcomes. Methods Fifty-five patients with clinical and radiological (US, CT, and/or MRI) suspicion of unilateral cavernous hemangioma of the orbit underwent 99mTc-RBC SPECT study. Methods Qualitative and semiquantitative evaluations were performed, and results were statistically analyzed. Results SPECT images showed focal uptake in the orbital mass in 36 of 55 patients. Nineteen patients had a negative scintigraphic pattern, with concordance of early and late absence of uptake of 99mTc-RBC. Results Our procedure showed 100% sensitivity and 88.9% specificity for the diagnosis of orbital cavernous hemangioma, with a positive predictive value of 90.9% and a negative predictive value of 100%. Conclusions 99mTc-RBC imaging is safe, easy to perform, and highly accurate in providing adequate clinical and surgical management. As a noninvasive and highly specific method for diagnosing orbital hemangioma, 99mTc-RBC scintigraphy can avoid more invasive imaging or biopsy.

This is a case of a 48-year-old man treated with surgery and (131)I for papillary thyroid carcinoma: a follow-up (18)F-FDG PET/CT incidentally evidenced pituitary uptake, also seen in (111)In-octreoscan as increased uptake in the sellar area. MRI confirmed a pituitary mass. The patient did not show any signs or symptoms related to this lesion; 1 year later, both PET/CT and MRI findings remained unchanged. Surgery confirmed nonfunctioning benign pituitary adenoma. This single case observed in 12,873 consecutive patients scanned in our center confirms the possibility that nonfunctioning benign pituitary adenomas may be FDG-avid: uptake mechanisms remain unknown, and targeted studies are needed.

PURPOSE: Patients treated for ovarian cancer are usually referred for 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) in case of increased Carcinoma Antigen 125 (CA125) but negative conventional imaging. However, there is not enough in the literature to support the value of FDG PET/CT in this context. This study aimed to assess role of FDG PET/CT in a cohort of patients with treated ovarian cancer and correlate the results with serum levels of CA125. PROCEDURES: We retrospectively studied 175 patients, mean age 65.2 years (range 24-88 years) who had radical treatment for ovarian cancer (chemotherapy, surgery or combination). The patients had a standard FDG PET/CT and measurement of serum CA125 within a month of the scan. PET/CT was considered positive if demonstrated areas of abnormally increased metabolic activity unrelated to physiological distribution, on the basis of a visual analysis. The results of PET/CT imaging were compared to the level of CA125, and receiver operating characteristic (ROC) curves were plotted and area-under-the curve (AUC) statistics were computed. Cytologic or histologic data or clinical and imaging follow-up were taken as gold standard. RESULTS: Patients were divided into five groups based on CA125 values. The average level of CA125 was 107.7 (range 3-867, SD 166.1). PET/CT was positive in 125/175 cases (71.4%), mean value of CA125 132.2 (SD 182.9) and negative in 50/175 (28.6%), mean value of CA125 46.4 (SD 89.3). In descriptive ROC analyses, the discriminatory power of this marker was relatively high (AUC statistics 0.77, range = 0.703-0.8). The optimal cut-off point of CA125 after treatment to reflect active disease on PET/CT was 18 U/mL achieving a detection rate of 85.6%. There was no relation between PET/CT negativity and the histological type of the tumor. CONCLUSION: PET/CT was able to detect active disease at relatively low levels of CA125, thereby facilitating the early diagnosis of recurrence or residual disease. Also in patients with low CA125 levels (