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Purpose: Incidental solitary pulmonary nodules (SPNs) have become an increasingly common CT finding worldwide. Although there are currently many imaging strategies for evaluating SPNs, the differential diagnosis and management of SPNs remains complex because of overlap between benign and malignant processes. Moreover, transbronchial or percutaneous CT-guided biopsies do not always allow definitive diagnoses. In such cases, video-assisted thoracic surgery (VATS) has become the preferred surgical procedure for diagnosis and, in selected cases, for treatment of indeterminate SPNs. The difficulties in localizing smaller, deeper, and ground-glass nodules have been approached with different techniques. The aim of this study was to report 20 years of experience with radioguided thoracoscopic resection of SPNs at the Regional Centre of Nuclear Medicine of Pisa., Methods: Three hundred ninety-five patients with SPNs less than 2 cm and deeper than 5 mm below the visceral pleura underwent CT-guided injection of a suspension composed of 0.1 to 0.2 mL Tc-labeled human albumin macroaggregates (Tc-MAA) and of 0.2 to 0.3 mL of nonionic contrast medium into or adjacent to the SPN. During VATS, the pulmonary area with the highest target/background ratio identified by an 11-mm-diameter collimated thoracoscopic gamma probe was resected., Results: From 1997 to 2016, approximately 395 patients with SPN underwent VATS wedge resection using the radioguided technique. Mean SPN size was 13 mm (range, 5-20 mm) with mean distance of 15 mm (range, 6-39 mm) from the visceral pleura. Mean VATS procedural time was 40 minutes (range, 20-90 minutes), with an average time of 3 minutes (range, 1-5 minutes) to localize the nodule. Neither mortality nor major perioperative complication was reported. The success rate of VATS with radioguidance in our series was 99%. Histological examination revealed 206 benign lesions (52%), 59 primary lung tumors (15%), and 130 metastatic nodules (33%)., Conclusions: This study demonstrates that radioguided SPN localization by VATS is a feasible, safe, and rapid procedure with highly successful rate of SPN resection.

The "non-recurrent" course of the inferior laryngeal nerve (ILN) is an anatomical variant which must be borne in mind during thyroid surgery. The "non-recurrent" course of the ILN on the right side is associated with the aberrant right subclavian artery (arteria lusoria), and, on the left, is described in situs viscerum inversus. We present a case in which the "arteria lusoria" was not associated with the non-recurrent right ILN. The aims of this paper are to report this "anomaly of the anomaly" to surgeons who may be unaware of it on the one hand and on the other to emphasize that this is the only case so far reported in the literature. Moreover we proposed to explain embryologically these unexpected findings.

Purpose: The aim of this retrospective study was to assess the value of 18F-FDG PET/CT in the initial evaluation and follow-up of patients with tuberculosis (TB)., Patients and Methods: Thirty-five patients (18 men) with pulmonary or extrapulmonary TB were included. Diagnosis of TB was based either on histology or microbiological assessment in 32 patients and was based on typical morphological features of TB in CT and improvement on antimycobacterial medication in 3 patients. Eighty-eight 18F-FDG PET/CT scans were performed at initial assessment and during treatment, on a Siemens Biograph PET/CT. Diagnostic contrast-enhanced CT scans were performed on the 40-slice multidetector CT of the PET/CT scanner. Mean (SD) anti-TB treatment duration was 16.1 (8.9) months., Results: The initial 18F-FDG PET identified 64 affected regions in 34 among 35 patients, whereas CT identified 34 affected organs in 23 patients. Matching image results between PET and CT were observed at first visit in 11 patients (31.4%), with relevant differences in 23 (65.7%). In 1 patient, both modalities remained negative. During follow-up 18F-FDG PET scans, we recorded 15 cases with remission of disease, 16 with residual disease (2 patients with multidrug-resistant infection), and 4 cases with progressive disease or delayed onset of adequate immunological response. In only 3 patients, both modalities, PET and CT, showed completely equivalent results., Conclusions: Both components of 18F-FDG PET/CT provide complementary information at initial evaluation and during follow-up; however, 18F-FDG showed more abnormal findings than CT. 18F-FDG PET/CT might be useful for the establishment of individualized treatment regimes, but this requires further prospective studies.

The aim of this article was to review the current role of PET/computed tomography (CT) in soft tissue sarcomas with respect to staging, restaging, and prognostic value. Fluorine-18-fluorodeoxyglucose PET, for instance, can be very useful in differentiating recurrent disease from scar tissue during follow-up. Other indications of PET-CT are still evolving, especially in the light of new molecular drugs. Different aspects of PET/CT imaging in soft tissue sarcomas are overviewed including organ-specific merits, limitations, and potential pitfalls. Finally, methodological considerations on PET/MRI are also briefly discussed.

A 32-year-old man with melanoma on the right paramedian region of the lower back underwent lymphoscintigraphy for radioguided sentinel node (SN) biopsy. Planar imaging showed the presence of 2 sites of radioactivity accumulation corresponding to an axillary SN and to an "in-transit" SN, located on the right side of the upper trunk. A further "hot spot" placed on the left paramedian region of the lower back was identified by planar lymphoscintigraphy. This last finding could be mistaken for another "in-transit" SN, but SPECT/CT demonstrated it was actually a nonspecific radiopharmaceutical accumulation at the level of the right renal pelvis.

Purpose: We review acquisition F-choline PET/CT methodology, evaluate a new F-choline acquisition protocol for prostate cancer (PC), and propose a standardized acquisition protocol on F-choline in PC patients., Materials: Two hundred fifty consecutive PC patients (mean age 72 years, mean PSA 7.9 ng/mL) were prospectively evaluated with F-choline PET/CT. An early scan of the pelvis (1 bed position of 4 minutes) was followed by a whole-body scan at 1 hour. Early and 1 delayed hour images of the pelvis were compared., Results: Twenty-one percent of patients (n = 57) with positive F-choline demonstrated abnormal local uptake; 18% of patients (n = 45) showed distant localization only; 23% of patients (n = 53) had both local and distant localization; 38% of patients (n = 38) did not show any pathological uptake. All early images showed absence of radioactive urine in ureters, bladder, or urethra with satisfactory visualization of the prostatic region. Considering the group of patients with local uptake only, the prostatic region uptake, confirmed by late images, was better visualized in the early phase in 32/57 cases (SUVmax 12.4 ± 3.2 vs. 7.3 ± 5.2, P <0.01). Instead distant lesions were visualized on both early and late images with similar uptakes values (SUVmax 9.8 ± 4.1 vs. 10.3 ± 4.5, P = N.S.)., Conclusion: Early F-choline images improve pelvic prostate cancer lesion clarity. All pathologic pelvic deposits (prostate, lymph nodes, bone) were visualized both in the early and late images.

Aim: The aim of this study was to compare C-choline PET/CT, prostate-specific antigen (PSA), PSA kinetics, and C-choline uptake in recurrent metastatic prostate cancer patients with osteoblastic and osteolytic bone metastases., Patients and Methods: We retrospectively analyzed 140 patients with the following criteria: (a) positive bone lesions identified with C-choline PET/CT and validated as true positive by histology (14.2%), correlative imaging (33.4%), or clinical follow-up (52.4%); (b) after radical prostatectomy (67.9%) or primary radiotherapy (22.1%); (c) proven biochemical relapse with rising PSA levels; (d) no chemotherapy, zoledronic acid, or palliative bone external beam radiation therapy previously administrated during biochemical relapse; and (f) asymptomatic for bone pain. Lesions were categorized as osteoblastic, osteolytic, or bone marrow lesions. Patients were divided into osteoblastic and osteolytic patient groups., Results: C-Choline PET/CT detected oligometastatic bone disease (1-3 lesions) in 98 (70%) of the 140 patients and multiple bone lesions in 42 (30%) of the 140 patients. By per-lesion analysis of 304 lesions, there were 184 osteoblastic, 99 osteolytic, and 21 bone marrow lesions.By per-patient analysis, 97 (69.3%) of the 140 patients were in the osteoblastic group, whereas 43 (30.7%) of the 140 patients were in the osteolytic group. Statistically significant differences in SUVmax (P < 0.001), fast PSA doubling time (P = 0.01), and PSA velocity (P = 0.01) were observed between osteoblastic (lower values) and osteolytic (higher values) groups. By multivariate analysis, fast PSA doubling time was a significant predictor for osteolytic lesions., Conclusions: We demonstrated differences in PSA kinetics and SUVmax between osteolytic and osteoblastic lesions. C-Choline PET/CT may identify patients that could benefit from early targeted therapies, depending on the type of bone lesions expressed.

Purpose: Fluorine-18 fluorodeoxyglucose (¹⁸F-FDG)-PET/computed tomography (CT) is used for assessment of the extent and activity of disease in patients with inflammatory granulomatous lung disease, in particular sarcoidosis and tuberculosis. The aim of this retrospective analysis was to assess the value of ¹⁸F-FDG-PET/CT in the identification of previously unknown malignant disease during routine investigation of granulomatous lung disease., Materials and Methods: From July 2008 to December 2013, a total of 122 patients with tuberculosis (76 male and 46 female patients; age range 19.6-88.6 years, mean 52.8±16.6 years) and 85 patients with sarcoidosis (46 male and 39 female patients; age range 17.8-76.5 years, mean 48.6±13.8 years) underwent ¹⁸F-FDG-PET/CT. Reports were generated in consensus by both a nuclear medicine physician and a radiologist. Possibly malignant findings underwent biopsies and/or follow-up. Quantitative parameters (maximum standardized uptake value) were pooled and compared from reference lesions in each group., Results: Malignant disease was suspected in 18 of 122 tuberculosis patients and in eight of 85 sarcoidosis patients. Malignancy was finally confirmed in six patients with tuberculosis and in two patients with sarcoidosis. In one single case a malignant lung tumour had been overlooked on PET/CT. Patients were also analysed according to their age. In the patient group older than 60 years, four malignancies were confirmed in 44 tuberculosis patients and in one in 20 sarcoidosis patients, whereas in patients aged between 30 and 60 years only three of 63 tuberculosis and one of 58 sarcoidosis cases showed malignancy compared with the 18 false-positive findings on a total patient basis. The most common site of malignant disease was the chest. Besides the intrathoracic findings, two cases of malignancy were detected outside the thorax. Quantitative evaluation did not reveal any statistically significant difference between the tuberculosis and sarcoidosis groups., Conclusion: Differentiation between granulomatous inflammation and malignancy is challenging with ¹⁸F-FDG-PET/CT because of a large number of false-positive findings. The highest probability of detecting coexistent malignant disease was seen in patients older than 60 years who were suffering from tuberculosis. An important feature for identification of malignant disease, especially in the assessment of intrathoracic findings, has turned out to be the CT pattern; quantitative evaluation, in contrast, seems to have little clinical value.

PET/CT with (18)F-fluorodeoxyglucose (FDG) or using different radiocompounds has proven accuracy for detection of adrenal metastases in patients undergoing cancer staging. It can assist the diagnostic work-up in oncology patients by identifying distant metastases to the adrenal(s) and defining oligometastatic disease that may benefit from targeted intervention. In patients with incidentally discovered adrenal nodules, so-called adrenal "incidentaloma" FDG PET/CT is emerging as a useful test to distinguish benign from malignant etiology. Current published evidence suggests a role for FDG PET/CT in assessing the malignant potential of an adrenal lesion that has been 'indeterminately' categorized with unenhanced CT, adrenal protocol contrast-enhanced CT, or chemical-shift MRI. FDG PET/CT could be used to stratify patients with higher risk of malignancy for surgical intervention, while recommending surveillance for adrenal masses with low malignant potential. There are caveats for interpretation of the metabolic activity of an adrenal nodule on PET/CT that may lead to false-positive and false-negative interpretation. Adrenal lesions represent a wide spectrum of etiologies, and the typical appearances on PET/CT are still being described, therefore our goal was to summarize the current diagnostic strategies for evaluation of adrenal lesions and present metabolic and anatomic appearances of common and uncommon adrenal lesions. In spite of the emerging role of PET/CT to differentiate benign from malignant adrenal mass, especially in difficult cases, it should be emphasized that PET/CT is not needed for most patients and that many diagnostic problems can be resolved by CT and/or MR imaging.

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.

The value of 18F-FDG PET/CT in the initial diagnosis and in the locoregional staging of esophagogastric junction adenocarcinoma is not fully established. However, 18F-FDG PET/CT is widely accepted as the best modality for identification of suspected metastases in staging of the disease. Results published in the literature suggest that 18F-FDG PET/CT may provide useful information for response assessment to neoadjuvancy and to differentiate responding and nonresponding tumors. We review the potential role of 18F-FDG PET/CT imaging in staging, restaging, and prognostic value after chemoradiation therapy in esophagogastric junction adenocarcinoma.

Aim: The aim of this study was to evaluate the potential role of C-choline-PET/CT in nodal assessment in patients with bladder cancer (BCa) using the pathological specimen as reference standard., Patients and Methods: Fifty-nine patients with proven BCa were retrospectively enrolled from April 2011 to January 2014 (mean [SD] age, 70.1 [9] years; range 49-85 years). Of 59 patients, 39 (staging group) were referred to C-choline-PET/CT for preoperative lymph node (LN) evaluation before radical cystectomy and extended pelvic LN dissection. Of the 59 patients, 29 (restaging group) had C-choline-PET/CT for suspected BCa relapse after primary radical surgery. In both groups, C-choline-PET/CT findings were correlated with histology. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated to assess C-choline-PET/CT feasibility in LN assessment. Age, TNM, histology, and previous chemotherapy were analyzed as additional predictive factors., Results: C-choline-PET/CT overall detection rate was 62.7% (37/59 patients). On a regional-based analysis, C-choline-PET/CT was considered positive for primary cancer and/or local relapse in bladder bed in 54.2% of the patients (32/59). Pathological LN uptake was reported in 23.7% of the patients (14/59) and systemic choline deposit (bone or lung) in 11.8% of the patients (7/59). Considering LN metastasis detection, compared with histological analysis, C-choline-PET/CT showed in the whole population a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 59%, 90%, 71%, 84%, and 81%, respectively. No other investigated factors reached statistical significance., Conclusions: C-choline-PET/CT may provide additional diagnostic information in preoperative nodal staging of patients with BCa and be considered a useful tool to restage patients with BCa suspected of relapse. Further studies are needed to assess if C-choline-PET/CT could have an influence on survival of patients with BCa.

Malignant insulinoma is an extremely rare pancreatic tumor variant characterized by an aggressive clinical behavior with local and distant spread. Delays in the diagnosis are common because symptoms usually precede tumor detection and may be misattributed. Aggressive surgical resection is the primary treatment option; therefore accurate tumor localization is important for appropriate management. Although somatostatin receptor imaging has a limited role in the visualization of benign insulinoma (characterized by a low expression of somatostatin receptors), it can still have a role in the detection of malignant forms.

A patient with diffuse osteosclerotic bone metastases from invasive lobular breast carcinoma is presented with both F-FDG PET/CT and bone scans negative for hypermetabolic lesions. Skeletal metastases were documented by CT and bone marrow biopsy, and high increased CA 15-3 level was recorded. This case report points to the potential risk of false-negative FDG PET and bone scans examination in lobular carcinoma type.

Aim: The aim of this study was to evaluate of C-choline PET/CT in bladder cancer (BC) patients with suspected relapse after primary therapy., Methods: Twenty-five BC patients with surgery (21 [84%]) or radiotherapy (4 [16%]) with curative intent had PET/CT for suspicion of relapse. Mean TNM was T2b N0 M0 (range, T1a N0 M0 to T4 N2 M0), whereas mean age was 71.3 years (range, 50-85 years). Nine (36%) of 25 were treated with adjuvant or salvage chemotherapy within 6 months before PET/CT. Positive findings were validated by histology or correlative imaging and/or clinical follow-up lasting at least 12 months. Age, TNM, histology, previous chemotherapy, and type of primary treatment were correlated with PET/CT positivity by univariate and multivariate binary logistic regression analysis., Results: C-choline PET/CT was positive in 16 (64%) of 25. Six (37.5%) of 16 were positive in residual bladder/bladder bed, with 2 local false positive (FP) and 1 false negative (FN) on lymph nodes (LNs); 3 of 16 patients had PET-positive LNs with 1 FP; 1 of 16 patients showed distant metastases. Two (12.5%) of 16 had positive residual bladder/bladder bed and locoregional LNs; 1 (6.3%) of 16, residual bladder/bladder bed and bone; metastasis, 1 (6.3%) of 16 residual bladder/bladder bed and lung metastasis; 2 (12.5%) of 16, LN and distant metastasis. Five (56%) of 9 of PET negatives were FN in residual bladder/bladder bed. Eighteen (72%) of 25 were validated by histology, with 7 (18%) of 25 by correlative imaging and/or clinical follow-up. C-choline PET/CT was sensitive, specific, and accurate, with good positive and negative predictive values for local relapse of 66.7%, 84.6%, 76%, 80%, and 73.3% and 90%, 93.3%, 92%, 90%, and 93.3% for LNs and distant relapse, respectively. No FP or FN was detected for distant metastasis. None of the investigated factors were statistically significant., Conclusion: C-choline PET/CT is useful for restaging BC suspected of relapse, especially for the evaluation of LN or distant metastases.

Purpose: The first aim of the review (aim 1) was to obtain the diagnostic performance values of (18)F-FDG PET for the detection and staging of liver metastases in patients with colorectal cancer (CRC), the second aim (aim 2) was to compare PET and conventional imaging modalities, and the third aim (aim 3) was to evaluate the impact of PET on patient management. The incidence of extrahepatic disease (EHD) detected by PET is also reviewed., Methods: A comprehensive search was performed on PubMed/MEDLINE for studies evaluating PET and PET/CT in CRC patients with liver metastases up to June 2014. For inclusion PET had to have been performed prior to surgery, there had to be at least 18 patients in the study, and the reported data had to allow calculation of 2 × 2 contingency tables (for aim 1). A total of 18 studies were eligible for at least one of the three intended subanalyses including a total of 1,059 patients. Pooled sensitivity, specificity and accuracy and the corresponding 95 % confidence intervals were derived from the contingency tables on a patient basis (patient-based analysis, PBA) and a lesion basis (lesion-based analysis, LBA) for eight studies., Results: Pooled sensitivity and specificity of PET on PBA were both 93 %. Corresponding values for LBA were 60 % and 79 %, respectively. Areas under the summary ROC were 0.97 for PBA and 0.67 for LBA. Regarding aim 2, PET had a slightly lower sensitivity than MRI and CT on PBA (93 %, 100 % and 98 %, respectively) and LBA (66 %, 89 % and 79 %, respectively) but appeared to be more specific than MRI and CT (86 %, 81 % and 67 %, respectively). PET findings resulted in changes in the management of a mean of 24 % of patients. The mean incidence of PET-based EHD was 32 %., Conclusion: This meta-analysis suggests that FDG PET/CT is highly accurate for the detection of liver metastases on a patient basis but less accurate on a lesion basis. Compared to MRI, PET is less sensitive but more specific and affects the management of about one-quarter of patients.

F-FDG PET/CT has a limited role in the evaluation of locoregional bladder cancer because of the interference of radioactive urine. Methods proposed to overcome interference are based on F-FDG washout and include late images after voiding, catheterization, bladder irrigation, and forced diuresis. We performed a very early F-FDG PET/CT acquisition of the pelvic region in a man with bladder cancer with wall invasion in order to evaluate the feasibility and usefulness of this method to visualize bladder cancer. Early images revealed a pathologic accumulation of the tracer in the posterior left wall of the bladder that was thickened on the CT images.

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.

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 prognostic factor.

Purpose: Male breast cancer (BC) is a rare disease, with patterns different from those found in women. Most tumors are detected at more advanced stages than in women. The aim of this study was to analyze the performance of [18F]fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) in staging, restaging, and therapy response assessment., Methods: We performed a systematic analysis in the database of Saint-Louis Hospital to identify male patients with BC referred for PET/CT. (18)F-FDG-PET/CT findings considered suspicious for malignancy were compared to biopsy results, further work-up and/or patient follow-up of at least 6 months. Performances of (18)F-FDG-PET/CT were compared to that of conventional imaging (CI) using the McNemar test. The impact of PET/CT on management was evaluated., Results: During 6 consecutive years, among 12,692 (18)F-FDG-PET/CT oncology studies, 30 were performed in 15 men with BC: 7 examinations for initial staging, 11 for restaging, and 12 for response assessment. Tumors profile was ER+ and one had HER2 overexpression. PET/CT sensitivity, specificity, positive predictive value, negative predictive value and accuracy to detect distant metastases were 100%, 67%, 86%, 100% and 89%, respectively. PET/CT was more informative than CI in 40% of studies (p=0.03; 95% confidence interval: 3.26 - 40%). Findings from (18)F-FDG-PET/CT led to modification in the planned treatment in 13/30 cases (43%)., Conclusion: Although all the tumors were ER+, primary lesions and metastases were diagnosed with high sensitivity. (18)F-FDG-PET/CT seems to be a powerful imaging method to perform staging, restaging and treatment response assessment in male patients with BC., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

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., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Nuclear medicine imaging of endocrine disorders takes advantage of unique cellular properties of endocrine organs and tissues that can be depicted by targeted radiopharmaceuticals. Detailed functional maps of biodistributions of radiopharmaceutical uptake can be displayed in three-dimensional tomographic formats, using single photon emission computed tomography (CT) that can now be directly combined with simultaneously acquired cross-sectional anatomic maps derived from CT. The integration of function depicted by scintigraphy and anatomy with CT has synergistically improved the efficacy of nuclear medicine imaging across a broad spectrum of clinical applications, which include some of the oldest imaging studies of endocrine dysfunction.

A 35-year-old man underwent contrast-enhanced MRI and F-FDG PET/CT for acute peripheral paresthesia, vision loss, muscle weakness, and difficulty walking. T2-weighted MRI demonstrated multiple bright periventricular supratentorial and infratentorial white matter lesions, including 2 with nodularity. Both nodular lesions showed moderate focal FDG uptake (SUVmax, 6.9 in both cases). Cerebrospinal fluid analysis showed increased levels of immunocytes and oligoclonal antibody bands. A diagnosis of acute onset tumefactive multiple sclerosis was made.

Purpose: This study evaluates the use of sequential I PET/CT for predicting absorbed doses to metastatic lesions in patients with differentiated thyroid cancer undergoing I 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 I. 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 I therapeutic dose was 5994 MBq (range, 1953-11,455 MBq)., Results: I PET/CT demonstrated all lesions detected by posttherapy I 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 I uptake., Conclusions: The quantitative value of I PET/CT allows simple and accurate evaluation of lesion dosimetry following medical internal radiation dose formalism. Negative I PET/CT predicts absence of iodine avidity, potentially allowing avoidance of therapeutically ineffective I administration.

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 < 0.05). Moreover, the DR in patients under ADT (mean PSA 7.8 ng/ml) was higher than in patients not under ADT (mean PSA 3.9 ng/ml), (DR was 70.5 % and 48.9 %, respectively; p < 0.001), therefore, demonstrating the existence of a significant correlation between the DR of (18)F-CH PET and ADT. In group B patients only trigger PSA resulted a reliable predictor of the (18)F-CH positivity, since ADT was not correlated to the DR of (18)F-CH PET (p = 0.061). Also in group B the DR of (18)F-CH PET in patients under ADT was higher than in patients not under ADT (65.3 % and 51.3 %, respectively) but the difference was not significant without a statistically significant correlation in the Mann Whitney test (p = 0.456) therefore, suggesting the lack of correlation between DR (18)F-CH PET/CT and ADT., Conclusion: Similarly to previous published studies, in our series the overall DR of (18)F-CH PET/CT was 58 % and was significantly correlated to trigger PSA. The most important finding of the present study is that ADT does not negatively influence DR of (18)F-CH PET/CT in PC patients with biochemical relapse; therefore, it can be suggested that it is not necessary to withdraw ADT before performing (18)F-CH PET/CT.

18F-DOPA is a radiopharmaceutical with interesting clinical applications and promising performances in the evaluation of the integrity of dopaminergic pathways, brain tumors, NETs (especially MTCs, paragangliomas, and pheochromocytomas), and congenital hyperinsulinism. 18F-DOPA traces a very specific metabolic pathway and has a very precise biodistribution pattern. As for any radiopharmaceutical, the knowledge of the normal distribution of 18F-DOPA, its physiologic variants, and its possible pitfalls is essential for the correct interpretation of PET scans. Moreover, it is important to be aware of the potential false-positive and false-negative episodes that can occur in the various clinical settings.

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.

Aim: : Nuclear medicine has entered a new era of multimodality imaging. Single-photon emission computed tomography/computed tomography (SPECT/CT) hybrid cameras are relatively new diagnostic tools that have been widely adopted and are present in most nuclear medicine units. SPECT/CT instruments allow functional and morphologic images to be acquired as superimposed (fusion images) in a single session., Methods: The integration of CT enables better characterization of functional abnormalities identified on planar and SPECT scintigraphy by offering structural information. It thus highly improves accuracy compared with conventional scintigraphy., Results and Conclusions: The combination of functional information and anatomic localization has the potential to influence medical practice with newer imaging algorithms. This review presents the current evidence and potential indications of SPECT/CT imaging in the initial staging, treatment, and follow-up of patients with differentiated thyroid cancer.

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.

Aim: The aim of this study was to evaluate the role of C-choline PET/CT in the preoperative evaluation of the nodal involvement of patients with bladder carcinoma (BC) suitable for radical cystectomy and extended pelvic lymph node dissection in comparison with contrast-enhanced CT (CECT) using the pathologic specimen as reference standard., Patients and Methods: Twenty-six consecutive patients (69.5 ± 9.3 years; range, 49-84) with histologically proven transitional cell BC were treated with radical cystectomy and pelvic lymph node dissection and were enrolled from April 2011 to January 2013. In all patients, paravesical, internal, eternal, and common iliac nodes as well as obturatory, presacral, preaortic, and precaval lymph nodes (LNs) were dissected up to the origin of the inferior mesentery artery. The areas of the LN dissection were grouped as follow: region A included preaortic and precaval LNs; region B included paravesical, common, internal and external iliac, obturatory, and presacral LNs in the right pelvis; region C included paravesical, common, internal and external iliac, obturatory, and presacral LNs in the left pelvis. C-choline PET/CT and abdominal CECT were used to assess the presence of lymph node metastases on a per patient, region, and lesion analysis using the results of surgical specimens obtained at operation as criterion standard., Results: Seven of 26 patients (26.9%) showed nodal metastases at pathologic analysis. Overall, 844 LNs were evaluated, and 38 of them (4.5%) showed metastatic involvement. On a patient-based analysis, C-choline PET/CT showed a sensitivity of 42% and specificity of 84%, whereas, CECT showed a sensitivity of 14% and specificity of 89%. On a region-based analysis, C-choline PET/CT showed a sensitivity of 11% and specificity of 82%, whereas CECT showed a sensitivity of 5% and specificity of 80%. On a lesion (LN)-based analysis, C-choline PET/CT showed a sensitivity of 10% and specificity of 64%, whereas CECT showed a sensitivity of 2% and specificity of 63%., Conclusions: C-choline PET/CT could provide additional diagnostic information in preoperative nodal staging of patients with invasive BC in comparison with CECT. A study with a larger population should determine if C-choline PET/CT could be recommended as a routine technique in high-risk patients with BC.

Aim: The purpose of this study was to conduct a systematic review of the published literature to assess the role (indications, advantages, and limitations) of SPECT/CT for the detection of sentinel lymph node (SLN) in breast cancer., Methods: The authors searched PubMed for published literature in English addressing this topic., Results: Eleven studies, published since 2006, focused on the role and value of SPECT/CT for SLN detection (SLND). They showed that SPECT/CT improved sentinel node detection and anatomical localization. One study suggested that SPECT/CT may provide a more accurate staging. Limitations for SLND with SPECT/CT include extra time and inconvenience for the patient and additional radiation dose., Conclusions: SPECT/CT is a valuable tool for SLND, especially in difficult cases, when planar lymphoscintigraphy shows no SLN or unexpected lymphatic drainage.

Purpose: Testicular tumour is the most common malignancy in young men. The diagnostic work-up is mainly based on morphological imaging. The aim of our study was to evaluate the clinical impact of (18)F-FDG PET/CT in patients with testicular tumour., Methods: We retrospectively evaluated all patients studied by (18)F-FDG PET/CT at our centre. Inclusion criteria were: pathological confirmation of testicular tumour, contrast-enhanced CT scan performed within a month of the PET/CT scan, and clinical/imaging follow-up performed at the Oncology Unit of our hospital. Overall, 56 patients were enrolled and 121 PET/CT scans were evaluated. (18)F-FDG PET/CT was performed following standard procedures and the results were compared with clinical, imaging and follow-up data. Clinicians were contacted to inquire whether the PET/CT scan influenced the patient's management. Answers were scored as follows: start/continue chemotherapy or radiotherapy, indication for surgery of secondary lesions, and clinical surveillance., Results: On a scan basis, 51 seminoma and 70 nonseminoma (NS) cases were reviewed. Of the 121 cases. 32 were found to be true-positive, 74 true-negative, 8 false-positive and 6 false-negative by PET/CT. PET/CT showed good sensitivity and specificity for seminoma lesion detection (92% and 84%, respectively), but its sensitivity was lower for NS forms (sensitivity and specificity 77% and 95%, respectively). The PET/CT scan influenced the clinical management of 47 of 51 seminomas (in 6 chemotherapy was started/continued, in 3 radiotherapy was started/continued, in 2 surgery of secondary lesions was performed, and in 36 clinical surveillance was considered appropriate), and 59 of 70 NS (in 18 therapy/surgery was started/continued, and in 41 clinical surveillance was considered appropriate)., Conclusion: Our preliminary data demonstrate the potential usefulness of PET/CT for the assessment of patients with testicular tumour. It provides valuable information for the clinical management, particularly for clinical surveillance, post-therapy assessment and when relapse is suspected.

Aim: The aim of this study was to assess the performance of FDG PET/ceCT simultaneously acquired, contemporary read and finally discussed by the radiologist and the nuclear medicine physician for staging and restaging lung cancer patients., Methods: We analysed 17 consecutive patients (7F; 10M; mean age 68). Six patients were in staging, 8 patients were in restaging (1 during therapy, 2 after therapy and 5 during the follow-up) and 2 patients needed to characterise a suspect pulmonary mass. All the patients underwent combined FDG PET/CT and ceCT acquired simultaneously on the same tomograph. The images were read and reported together by the nuclear medicine physician and the radiologist., Results: None of the patients had adverse reactions nor complained about the procedure. Thirteen FDG PET/ceCT turned out positive, while 4 were completely negative. Among positive patients, a significant SUV max was detected in all the cases (range 1.8-17.5). In the end, 9 patients had a true positive result, 4 true negative, 3 false positive and 1 false negative. Sensitivity, specificity and accuracy of the combined procedure were 90%, 57% and 76% respectively. In 7/17 patients FDG PET/CT and ceCT were completely concordant. FDG PET/CT provided a significant impact on the final interpretation in 7/17 patients while ceCT had a major impact in 3/17 patients., Discussion: This preliminary study shows that FDG PET/ceCT is a feasible technique for lung cancer patients, providing an optimal sensitivity (90%). From our results it is advisable not to include patients without an histological diagnosis of cancer due to possible false positivity of the two methods, significantly reducing specificity. However, a proper patient selection is not easy and the future of this combined test relies essentially on the capacity to early identify only the subjects who would really benefit from both the procedures., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Objective: The purpose of this study was to determine likelihood of malignancy for indeterminate lung nodules identified on CT comparing two standardized models with (18)F-FDG PET/CT., Materials and Methods: Fifty-nine cancer patients with indeterminate lung nodules (solid tumors; diameter, ≥5 mm) on CT had FDG PET/CT for lesion characterization. Mayo Clinic and Veterans Affairs Cooperative Study models of likelihood of malignancy were applied to solitary pulmonary nodules. High probability of malignancy was assigned a priori for multiple nodules. Low (<5%), intermediate (5-60%), and high (>60%) pretest malignancy probabilities were analyzed separately. Patients were reclassified with PET/CT. Histopathology or 2-year imaging follow-up established diagnosis. Outcome-based reclassification differences were defined as net reclassification improvement. A null hypothesis of asymptotic test was applied., Results: Thirty-one patients had histology-proven malignancy. PET/CT was true-positive in 24 and true-negative in 25 cases. Negative predictive value was 78% and positive predictive value was 89%. On the basis of the Mayo Clinic model (n=31), 18 patients had low, 12 had intermediate, and one had high pretest likelihood; on the basis of the Veterans Affairs model (n=26), 5 patients had low, 20 had intermediate, and one had high pretest likelihood. Because of multiple lung nodules, 28 patients were classified as having high malignancy risk. PET/CT showed 32 negative and 27 positive scans. Net reclassification improvements respectively were 0.95 and 1.6 for Mayo Clinic and Veterans Affairs models (both p<0.0001). Fourteen of 31 (45.2%) and 12 of 26 (46.2%) patients with low and intermediate pretest likelihood, respectively, had positive findings on PET/CT for the Mayo Clinic and Veterans Affairs models, respectively. Of 15 patients with high pretest likelihood and negative findings on PET/CT, 13 (86.7%) did not have lung malignancy., Conclusion: PET/CT improves stratification of cancer patients with indeterminate pulmonary nodules. A substantial number of patients considered at low and intermediate pretest likelihood of malignancy with histology-proven lung malignancy showed abnormal PET/CT findings.

SPECT/CT reinforces the role of lymphoscintigraphy in breast cancer by solving some cases with difficult reading on planar scintigraphy. An 80-year-old woman was referred to our institution for management of a screen-detected, nonpalpable, invasive lobular carcinoma of lower inner quadrant of the left breast. Lymphoscintigraphy was performed before surgery. Planar images showed an axillary sentinel node and 2 medially located hot spots. SPECT/CT allowed determining that one of the extra-axillary drainage sites was to the internal mammary basin, while the second corresponded to a mediastinal lymph node. Although this drainage was unexpected, mediastinum is a common site of breast cancer recurrence.

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.

The outcome of head and neck squamous cell cancer depends primarily on its prompt diagnosis and treatment. Unfortunately, in many cases ominous prognostic factors such as lymph node metastases or osteomandibular extension are present at the time of diagnosis. We review the relative efficacy of contrast-enhanced computed tomography (ceCT), MRI, and F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in the early detection of head and neck squamous cell cancer, as well as its impact on treatment management and outcomes. Medline and Web of Knowledge databases, from 2000 to January 2013, were evaluated. Ninety-seven reports were selected, but only 11 studies comparing PET or PET/CT with CT and 11 comparing PET or PET/CT with MRI were found appropriate for analysis. ceCT and MRI continue to be the reference imaging modalities for the study of primary tumors, especially in the evaluation of the extension of disease and its relationship with nearby anatomical structures. There is increasing evidence that F-FDG PET/ceCT can provide accurate anatomical details similar to ceCT alone, as well as accurate information on osteomandibular tumor invasion similar to MRI. The major advantage of PET/CT over other imaging methods is its ability to detect relatively small lymph node metastases located in difficult-to-interpret positions. PET/CT is also highly sensitive for the detection of distant metastases and in assessing the response to chemotherapy or chemoradiation treatment and in predicting outcome. ceCT and MRI are the gold standards for evaluating primary and osteomandibular tumoral infiltration. F-FDG PET/CT plays a major role in the detection of lymph node and distant metastases, in assessing the response to neoadjuvant/adjuvant chemotherapy or chemoradiation therapy, and in predicting outcome.

Purpose: This study aims to evaluate the role of F-DOPA PET/CT in staging and follow-up of paraganglioma syndromes succinate dehydrogenase (SDH)-mutation-related patients, comparing F-DOPA PET/CT results with morphological imaging and biochemical results., Patients and Methods: We retrospectively studied 10 consecutive patients (3 F, 7 M, mean age 32 yrs), all with a genetically demonstrated SDH mutation (5 SDH-D, 4 SDH-B, and 1 SDH-C) and all addressed to F-DOPA PET/CT scan. Seven patients had already been operated on for one or more pheochromocytomas and/or paragangliomas and were submitted to F-DOPA PET/CT scan according to clinical, biochemical, or radiological suspicion of recurrence, while 3 were only genetically positive, with no previous symptom/sign of the disease. For all patients, biochemical analysis (plasma and/or urinary catecholamine) and results of high-resolution morphological imaging studies (CT and/or MRI) were available. Histologic/cytologic findings or imaging and biochemical follow-up were taken as gold standard in all cases., Results: Seven out of 10 patients showed one or more areas of pathological F-DOPA accumulation. PET/CT demonstrated the presence of the disease in 4/6 patients with no increase in catecholamine levels ("biochemically silent"). Positive detection rate was 100% in SDH-D and 40% in "non-SDHD". Analyzing per lesion, F-DOPA PET/CT demonstrated more lesions than anatomical imaging (16 vs. 7) especially in head and neck paragangliomas., Conclusions: F-DOPA PET/CT seems to be the more accurate method for staging and restaging patients with SDH-mutations-related paraganglioma syndromes. F-DOPA is particularly useful in detecting head and neck and biochemically silent paragangliomas, and also in apparently healthy mutation-carrying people.

Purpose: (1) To evaluate a new acquisition protocol of (18)F-choline (FCH) PET/CT for prostate cancer patients (PC), (2) to review acquisition (18)F-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: Early (18)F-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.

Aims: Cu-diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM) is a hypoxia-avid, positron emitter radiotracer. The primary aim of this study is to assess the efficacy of pretherapy Cu-ATSM PET/CT as a prognostic factor of response to therapy. The secondary aims are to investigate if there is a difference between early and late PET/CT scans and if there is a difference between the biologic tumor volume (BTV) in radiotherapy treatment planning calculated between Cu-ATSM and F-FDG, and to assess if Cu-ATSM is a prognostic marker of disease progression., Methods: Eleven patients with head and neck cancer treated with chemoradiotherapy were enrolled prospectively; both Cu-ATSM and F-FDG PET/CT scans before and after treatment were obtained. The Cu-ATSM scans were performed after 1 hour (early) and 16 hours (late)., Results: All patients had stage III or IV squamous cell head and neck cancer; 7 of 11 patients had nodal metastasis, and 22 cancer foci were detected with Cu-ATSM. SUVmax was 16.2 ± 7.9, and there was no significant SUVmax difference between early and late imaging. F-FDG SUVmax before therapy was 15.6 ± 9.4, whereas F-FDG SUVmax after therapy was 1.5 ± 1.2. Sensitivity and specificity values of Cu-ATSM calculated with receiver operating characteristic curves were 100% and 50% considering the SUVmax and 100% and 33% considering the volume, respectively. No difference has been found between the BTV contoured with Cu-ATSM and F-FDG., Conclusions: The Cu-ATSM scans showed high sensitivity but low specificity in predicting neoadjuvant chemoradiotherapy response. No difference was noted between early and late scans. F-FDG and Cu-ATSM provided similar results about delineation of BTV.

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 combined use of SPECT and CT strongly supports the molecular imaging of neuroendocrine tumors (NETs) with somatostatin receptor radiopharmaceuticals or with meta-iodobenzylguanidine. SPECT/CT fusion images provide potential attenuation correction, higher specificity, and accurate localization for the staging, evaluation of treatment response, and follow-up of NETs.

A 59-year-old man presented with frequent urination. Six months ago, his prostate-specific antigen (PSA) was 1.56 ng/mL; currently it is 3.5 ng/mL (PSA doubling time = 6 months; PSA velocity = 0.19 ng/mL/mo). Biopsy revealed aggressive prostate cancer (Gleason score 5 + 5). Staging with (18)F-fluorocholine PET/CT ((18)F-FCH PET/CT) demonstrated lymph node metastasis. After 6 months of hormonal therapy with goserelin, PSA decreased to 0.38 ng/mL. A (18)F-FCH PET/CT restaging scan demonstrated a global reduction of (18)F-FCH lesion uptake with disappearance of some mediastinal and iliac pelvic lymph node activity.

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., Methods: 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: 1.0 < PSA ≤ 2.0 ng/ml (11 patients), 2.0 < PSA ≤ 4.0 ng/ml (16 patients), 4.0 < PSA ≤ 6.0 ng/ml (9 patients) and PSA > 6.0 ng/ml (10 patients). Correlation between ADT and PDR was investigated as well as between PSA and distribution of metastatic spread., Results: 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., Conclusion: 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.