Diagnostic relevance of 2-[18 F]-FDG PET/CT in patients recently diagnosed with monoclonal gammopathy of undetermined significance.

2-[18 F]-FDG PET/CT is a useful diagnostic technique to assess bone and soft tissue disease in multiple myeloma (MM) but is not recommended by the International Myeloma Working Group for the evaluation of monoclonal gammopathy of undetermined significance (MGUS). The objective of this study was to evaluate the role of 2-[18 F]-FDG PET/CT in the management of these patients. An observational retrospective study was conducted on 338 patients with MGUS who underwent 2-[18 F]-FDG PET/CT. The mean age was 70.80 ± 11.84 years, and 69.2% of patients had cardiovascular risk factors. Patients were classified according to their progression risk (Mayo Clinic). The mean post-diagnosis follow-up was 8.35 ± 14.46 months. Pathological findings were recorded in 49 patients: 30 with myeloma bone lesions (15 in the initial study and 15 in follow-up) and 19 with other neoplastic (n = 13) or pathologically significant findings (n = 6). Body mass index, monoclonal component rate (MCR) > 1 g/dL and ≥1 risk factors for MM were significant in univariate logistic regression analyses. The MCR emerged as the main predictor of a positive 2-[18 F]-FDG PET/CT in adjusted multivariate regression analysis, with an area under the receiver operating characteristic curve of 0.785 and cutoff for optimal sensitivity/specificity of 1.0 ng/mL (71.4% sensitivity, 71.2% specificity). 2-[18 F]-FDG PET/CT results correctly classify patients with MGUS and could improve the detection of bone lesions over existing techniques, with the additional possibility of detecting neoplastic processes. The best parameter to predict a positive 2-[18 F]-FDG PET/CT was the MCR.

Influence of body mass index and type of low-level exercise on the side effect profile of regadenoson.

PURPOSE: Regadenoson, an A2A adenosine receptor pharmacologic stress agent for radionuclide myocardial perfusion imaging (MPI), is administered as a single, fixed dose. We studied the side effect profile of regadenoson combined with two types of low-level exercise, according to body mass index (BMI). METHODS: Three hundred and fifty-six patients (46.1% men, mean age 67.7±10.7 years, range 31-90 years) underwent regadenoson stress testing combined with low-level exercise. Subjects were classified according to BMI as normal, overweight, or obese, and the type of low-level exercise performed as walking on the treadmill (TE group, n=190) or forcefully swinging legs while sitting (SS group, n=166). Patients' demographics, medical history, clinical symptoms during stress, changes in ECG, oxygen saturation (SatO2), systolic blood pressure (SBP), and heart rate (HR) were evaluated. RESULTS: Groups were comparable (p=ns) with regard to cardiovascular risks factors. The incidence of side effects was similar across BMI (p=ns), although the TE patients showed improved profiles over those with SS exercise, with a significantly lower incidence of flushing, dizziness and nausea/gastrointestinal discomfort (12.9% vs. 28.4%; 19.9% vs. 33.4%; 11.4% vs. 19.2%, respectively; all p<0.05). Regarding the hemodynamic response, we did not observe significant changes in SBP and HR after regadenoson administration across BMI categories. Comparing the TE and SS groups, no significant changes were observed in SBP, but there was a higher increase in HR in the TE group (p<0.05). CONCLUSIONS: Regadenoson in combination with low-level exercise is safe and well tolerated over a wide range of BMI, with TE exercise showing a better side effect profile than SS.

Compresión medular por tumor óseo pardo en paciente en hemodiálisis / Spinal cord compression due to a brown bone tumour in a patient on haemodialysis

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Ability of FDG-PET/CT in the detection of gallbladder cancer.

PURPOSE: To assess the value of FDG-PET/CT in the evaluation of gallbladder carcinomas (GBC). METHODS: A prospective cohort of patients with suspicion of or confirmed GBC was studied with FDG-PET/CT. Diagnostic accuracy parameters were calculated in comparison with pathology and/or the clinical course of patients. Clinical impact of PET/CT imaging was estimated. RESULTS: Forty-nine patients were enrolled (34 malignant tumors, 15 benign lesions; 37 staging, 12 restaging). Overall diagnostic accuracy was 95.9% for the diagnosis of the primary lesion, 85.7% for lymph node involvement and 95.9% for metastatic disease. Mean SUVmax in malignant gallbladder lesions was 7.92 ± 6.25 Analysis of ROC curves showed a SUVmax cut-off value of 3.62 for malignancy (S: 78.1%; Sp: 88.2%). Diagnostic accuracy in the restaging group reached 100%. FDG-PET/CT changed the management of 22.4% of the population. COMMENTS: Diagnosis of malignancy or benignity of suspicious gallbladder lesions is accurately made with FDG PET/CT, allowing a precise staging of GBC due to its ability to identify unsuspected metastatic disease. SUVmax has a complementary role in addition to visual analysis.

Comparative study of the safety of regadenoson between patients with mild/moderate chronic obstructive pulmonary disease and asthma.

PURPOSE: To compare the safety of regadenoson, a selective agonist of A2A adenosine receptors, combined with low-level exercise, between subjects with mild/moderate chronic obstructive pulmonary disease (COPD) and asthma referred for myocardial perfusion imaging (MPI). METHODS: We studied 116 patients, of whom 67 had COPD and 49 asthma (62 % men, mean age 68.3 ± 11.3 years, range 31 - 87 years). Patient demographics, past medical history, medications, clinical symptoms during stress and changes in blood pressure (BP) and heart rate (HR) were evaluated. RESULTS: Both groups were comparable with regard to hypertension, dyslipidaemia, diabetes and medications with the exception of a higher rate of use of anticholinergics in patients with COPD and of antileukotrienes in asthmatics (58.2 % vs. 28.6 % and 1.5 % vs. 14.3 %, respectively; all p < 0.01). There was a higher incidence of dyspnoea in COPD patients and of headache and feeling hot in asthmatic patients (40.3 % vs. 22.4 %, 6 % vs. 18.4 % and 10.4 % vs. 26.5 %, respectively; all p < 0.05). Although there was no difference in the incidence of other adverse events, we observed a higher frequency in asthmatics of flushing, dry mouth, sweating and fatigue (1.5 % vs. 6.1 %, 14.9 % vs. 24.5 %, 0 % vs. 4.1 % and 37.3 % vs. 49 %, respectively). Adverse events were self-limiting, except in three patients who suffered persistent dyspnoea (2 of 67 COPD patients; 1 of 49 asthma patients) requiring theophylline administration. We observed no significant changes in BP among either group, but there was a tendency towards a higher increase in systolic BP in COPD patients following regadenoson administration (148.3 ± 27.6 vs. 154.6 ± 31.0 mmHg, p = 0.056). CONCLUSION: This study showed a good safety profile in our series of COPD and asthma patients undergoing MPI. Regadenoson was well tolerated by all patients, with dyspnoea, headache and feeling hot showing differences between groups.

A new method for the radiochemical purity measurement of ¹¹¹In-pentetreotide.

OBJECTIVES AND METHODS: The recommended method for the measurement of radiochemical purity (RCP) of ¹¹¹In-labelled pentetreotide is thin-layer chromatography with a silica gel as the stationary phase and a 0.1 N sodium citrate solution (pH 5) as the mobile phase. According to the supplier's instructions, the mobile phase must be prepared before the test is carried out, and the recommended stationary phase is off-market. We propose a new method for RCP measurement in which the mobile phase is acid citrate dextrose, solution A, which does not need to be prepared beforehand, and thin-layer chromatography is performed with a silica gel-impregnated glass fibre sheet as the stationary phase. We used both methods to measure the percentages of radiopharmaceutical and impurities. RESULTS: The range of RCP values obtained was 98.0-99.9% (mean=99.3%) by the standard method and 98.1-99.9% (mean=99.2%) by the new method. We observed no differences between the RCP values of both methods (P=0.070). CONCLUSION: The proposed method is suitable for RCP testing because it yields results that are in good agreement with those of the standard method and because it is easier to perform as the mobile-phase solution need not be prepared in advance.

Is FDG-PET suitable for evaluating neoadjuvant therapy in non-small cell lung cancer? Evidence with systematic review of the literature.

BACKGROUND: Neoadjuvant therapy response assessment is crucial in patients with non-small cell lung cancer (NSCLC). FDG-PET has emerged as a valuable tool for defining therapy response assessment in other tumours. AIM: To systematically review publications appearing in the literature describing induction therapy response assessment with FDG-PET in NSCLC. METHODS: We performed a bibliographic search and selected only prospective studies in order to include the highest levels of evidence. RESULTS: Nine of 497 potentially relevant publications were selected. The ranges of sensitivity, specificity, positive predictive value and negative predictive value for primary tumour response assessment were 80-100%, 0-100%, 42.9-100%, and 66.7-100%, respectively. Pooling data for N2 restaging after neoadjuvant response the overall sensitivity was 63.8% (95% CI, 53.3-73.7%) and overall specificity was 85.3% (95% CI, 80.4-89.4%). CONCLUSION: The results of the analysis do not support the use of FDG-PET as the only re-assessment tool for mediastinal lymph node evaluation for routine clinical use. FDG-PET seems to predict primary tumour response to induction therapy but it could not be shown by pooling analysis.

18F-fluorodeoxiglucose positron emission tomography for the evaluation of neoadjuvant therapy response in esophageal cancer: systematic review of the literature.

UNLABELLED: Neoadjuvant treatment is a relatively new therapeutic approach for locally advanced esophageal cancer. Response assessment is crucial for the treatment of these patients. Cross sectional imaging has traditionally being used as the elective method of response assessment. Recently, 18F fluorodeoxyglucose- positron emission tomography (FDG-PET) has emerged as a new valuable tool defining therapy response assessment in other tumors. AIM: We systematically reviewed the increasing number of publications appearing in the literature analyzing the utility of FDG-PET in the evaluation of neoadjuvant therapy response assessment. METHODS: We performed a bibliographic search according to the COSI protocol and selected only prospective studies to achieve the highest levels of evidence. Quality assessment was defined with the QUADAS questionnaire. RESULTS: Eight of 237 potentially relevant publications were selected for the analysis. Ranged sensitivity, specificity, positive predictive value, and negative predictive value for primary tumor response assessment were 27.3% to 93.3%, 41.7% to 95.2%, 70.8% to 93.3% and 71.4% to 93.5%, respectively, and for N restaging, 16.0% to 67.5%, 85.7% to 100%, 33% to 100% and 91.7% to 93.3%, respectively. The heterogeneity of the publications ruled out the possibility of meta-analysis. FDG-PET is more precise compared with computed tomography in the evaluation of induction therapy response assessment. CONCLUSION: FDG-PET seems to be the best available imaging modality for neoadjuvant therapy response assessment in esophageal cancer. But more prospective studies with larger populations are needed to confirm the power of this imaging tool in this aim and to determine the best analytical interpretation method and threshold to differentiate responders from nonresponding patients.

Utilidad de la tomografía por emisión de positrones en el manejo de los cánceres de cuerpo de útero / Utility of positron emission tomography in the management of uterine body cancer

En la actualidad, la estadificación de los tumoresdel cuerpo uterino es esencialmente quirúrgica. Noexiste consenso ni protocolos definidos para elseguimiento de este tipo de neoplasias. Lastécnicas de diagnóstico por imagen son solicitadasa criterio del clínico, habitualmente ante lasospecha de recurrencia, recidiva o diseminaciónde la enfermedad. Las técnicas de imagenestructural (tomografía computarizada y resonanciamagnética) presentan ciertas limitaciones para ladetección de recurrencias. La tomografía poremisión de positrones es una técnica de imagenfuncional cuya utilidad se ha demostrado enmultitud de neoplasias, que está suscitando ungran interés en los últimos tiempos en el campo dela oncología ginecológica. Se ha realizado unanálisis de los resultados de la bibliografíacientífica disponible sobre la utilidad de estatécnica en los carcinomas endometriales y lossarcomas de útero, tanto en su diagnóstico inicialcomo en su seguimiento

Currently, uterine body tumors are basicallysurgically staged. Established consensus or definedprotocols for the follow up of these neoplasms arelacking. Imaging techniques are usually requestedbased on the clinician’s criteria, usually suspicionof disease recurrence or progression. Structuralimaging techniques, such as computed tomographyor magnetic resonance imaging, present somelimitations in the detection of recurrent disease.Positron emission tomography is a functionalimaging technique with proven utility inneoplasms. In the last few years, interest in thistechnique has grown in the field of gynecologiconcology. We performed a literature review on theutility of positron emission tomography in the evaluation of endometrial cancers and uterinesarcomas, both in initial diagnosis and follow-up

Diagnostic accuracy of 201Thallium-SPECT and 18F-FDG-PET in the clinical assessment of glioma recurrence.

PURPOSE: Reliable differential diagnosis between tumour recurrence and treatment-induced lesions is required to take advantage of new therapeutic approaches to recurrent gliomas. Structural imaging methods offer a high sensitivity but a low specificity, which might be improved by neurofunctional imaging. This study aimed to test the hypothesis that incorporation of 18-fluoro-deoxy-glucose positron emission tomography (FDG-PET) increases the accuracy of this differential diagnosis obtained with 201Tl chloride-single-photon emission computed tomography (201Tl-SPECT). MATERIALS AND METHODS: Seventy-six patients (mean age 47.72 +/- 16.19 years) under suspicion of glioma recurrence, 42% with low-grade and 58% with high-grade lesions, were studied by (201)Tl-SPECT and FDG-PET, reporting results under blinded conditions using visual analysis. Tumour was confirmed by histological confirmation (23 patients) or clinical and structural neuroimaging follow-up (mean of 2.6 years). RESULTS: This population had a high disease prevalence (72%). Globally, highest sensitivity was obtained using 201Tl-SPECT assessed with MRI (96%) and highest specificity using FDG-PET + MRI (95%). FDG-PET appeared slightly better for confirming tumour recurrence, whereas 201Tl-SPECT was superior for ruling out possible recurrence (disease present in 38% of FDG-PET negative explorations). In the high-grade subgroup, there were no false-positive examinations (specificity: 100%), but sensitivity differed among techniques (201Tl-SPECT : 94%; 201Tl-SPECT + MRI: 97%; FDG-PET + MRI: 83%). In the low-grade subgroup, 201Tl-SPECT + MRI showed highest sensitivity (95%) and lowest posttest negative probability (9%); FDG-PET + MRI offered highest specificity (92%) with a posttest negative probability of 35%. CONCLUSIONS: FDG-PET does not clearly improve the diagnostic accuracy of (201)Tl-SPECT, which appears to be a more appropriate examination for the diagnosis of possible brain tumour recurrence, especially for ruling it out.

Positron emission tomography with 2-[18F]-fluoro-2-deoxy-D-glucose in the evaluation of postoperative endometrial cancer patients

Objective To evaluate the usefulness of positron emission tomography with 2-[18F]fluoro-2-deoxy-D-glucose (FDG-PET) in the follow-up of endometrial cancer patients with suspicion of recurrence due to elevated serum tumour markers and suggestive conventional imaging findings. Material and methods A retrospective review was conducted of 17 FDG-PET studies performed in 11 patients with a previous diagnosis of endometrial cancer (6 patients underwent 2 studies) between April 2002 and October 2005. Mean age of patients was 63.4 yrs (range, 52-69 yrs), and mean time since diagnosis was 56 months (range, 11 months - 12 yrs). Initially, 7 patients were in stage I, 3 in stage III, and 1 in stage IV (FIGO classification). Histologically, they corresponded to 8 endometrioid and 3 non-endometrioid cancers. Results FDG-PET showed infradiaphragmatic uptake in three patients and disseminated disease in seven; findings were negative in one patient. Computed tomography (CT, n=7) or magnetic resonance (MRI, n=7) images revealed infradiaphragmatic lesions in five patients and visceral lesions in two. All patients showed elevated serum tumour markers (CA125, n=9; CA19.9, n=2; CA15.3, n=2). FDG-PET results modified the information provided by conventional imaging techniques in seven patients and provided no additional information in the remaining four. There was histological confirmation of lesions in two patients. Nine patients were clinically followed up, including imaging studies (mean follow-up, 8.7 months; range, 3-20 months).

Diagnosis efficacy of structural (CT) and functional (FDG-PET) imaging methods in the thoracic and extrathoracic staging of non-small cell lung cancer.

PURPOSE: To evaluate the efficacy of FDG-PET in the definition of tumour lung node lesions and to compare the diagnostic validity of CT and FDGPET in the staging of patients with non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: Patients with clinical suspicion of potentially resectable NSCLC (n = 108) were studied by standard procedures in our setting, including fibrobronchoscopy, transthoracic fine-needle aspiration, thoracoabdominal CT and FDG-PET. PET images were analysed by researchers blinded to results of other imaging modalities. Definitive tumour diagnosis was by histopathological study in patients who underwent surgery and by specific imaging methods and biopsy, when available, in patients who did not. Diagnostic accuracy was evaluated by comparing CT/PET results with the definitive diagnosis. RESULTS: In 13% of patients, no FDG-PET findings were observed and the histological study was negative for tumour. In 22% of patients, FDG-PET detected metastatic disease (M0 by CT). For mediastinal involvement, global diagnostic accuracy was 0.90 with FDG-PET and 0.59 with CT. False positive FDG-PET findings were produced by inflammatory conditions and false negative findings by the small size or proximity of lymph nodes to primary tumour. Mediastinal staging by CT and FDG-PET was correct in 56% and 87% of patients, respectively. CT indicated mediastinal invasion in 17% of patients with no FDG-PET finding of mediastinal involvement. Conversely, mediastinal spread was undetected by CT in 14% of patients with FDG-PET findings of mediastinal involvement. CONCLUSIONS: Although complementary, the functional method (FDG-PET) is significantly superior to the structural method (CT) for detection of mediastinal tumour disease.

Fluorine-18 fluorodeoxyglucose PET in the preoperative staging of colorectal cancer.

INTRODUCTION: In patients with colorectal cancer (CC), preoperative evaluation and staging should focus on techniques that might alter the preoperative or intraoperative surgical plan. Conventional imaging methods (CT, MRI) have low accuracy for identifying the depth of tumour infiltration and have limited ability to detect regional lymph node involvement. The aim of this study was to evaluate the utility of FDG-PET in the initial staging of patients with CC in comparison with conventional staging methods and to determine its impact on therapeutic management. METHODS: One hundred and four patients with a diagnosis of CC (53 males and 51 females; mean age 66.76+/-12.36 years), selected prospectively, were studied for staging using a standard procedure (CT) and FDG-PET. When possible, the reference method was histology. RESULTS: In 14 patients, surgery was contraindicated by FDG-PET owing to the extent of disease (only 6/14 suspected by CT). FDG-PET revealed four synchronous tumours. For N staging, both procedures showed a relatively high specificity but a low diagnostic accuracy (PET 56%, CT 60%) and sensitivity (PET 21%, CT 25%). For M assessment, diagnostic accuracy was 92% for FDG-PET and 87% for CT. FDG-PET results led to modification of the therapy approach in 50% of patients with unresectable disease. FDG-PET findings were important, revealing unknown disease in 19.2%, changing the staging in 13.46% and modifying the scope of surgery in 11.54% (with a change in the therapeutic approach in 17.85% of those patients with rectal cancer). CONCLUSION: Compared with conventional techniques, FDG-PET appears to be useful in pre-surgical staging of CC, revealing unsuspected disease and impacting on the treatment approach.

Application of modern imaging methods in diagnosis of gallbladder cancer.

The poor prognosis of gallbladder cancer (GBC) is related to its dissemination capacity and usually late diagnosis due to its non-specific clinical appearance. Recent improvements in hepatobiliary surgery have underlined the importance of an early specific diagnosis, which requires a multidisciplinary approach and, when possible, specialized equipment. The first step in an early diagnosis is to identify patients in the appropriate epidemiological setting (e.g., incidental finding, chronic cholecystitis) for the correct interpretation of test results. It is desirable to enhance the sensitivity of the initial ultrasound (US) examination by use of the appropriate technology in skilled specialist hands. When GBC is suggested by US findings, FDG-PET can be considered complementary to establish the benign/malignant nature of the lesion and to obtain a primary staging study. If GBC is confirmed, thin slice spiral CT can contribute valuable information on local spread. In this regard, recent hybrid PET-CT systems provide structural and functional information simultaneously and may offer early and accurate T, N, and M staging with an improved specificity.

Positron-emission tomography with fluorine-18-fluoro-2-deoxy-D-glucose for gallbladder cancer diagnosis.

BACKGROUND: Recent advances in hepatobiliary surgery have underscored the need for presurgical diagnosis of gallbladder cancer. Frequently, clinical presentation, biochemical analysis, and structural ultrasound or computed axial tomography images do not enable definitive differentiation of cholecystitis or cholethiasis from gallbladder cancer. The aim of this study was to evaluate the role of fludeoxy glucose-positron-emission tomography (FDG-PET) in establishing the benign or malignant nature of gallbladder lesions. METHODS: A case series of 16 patients with clinical symptoms suggestive of biliary colic or chronic cholecystitis and with inconclusive ultrasound and/or computed axial tomography findings for presence of gallbladder cancer were studied by FDG-PET. RESULTS: FDG-PET showed a sensitivity of 0.80, a specificity of 0.82, and positive and negative predictive values of 0.67 and 0.90, respectively. There was 1 false- negative result in 1 patient with mucinous adenocarcinoma and 2 false-positive results in 1 patient with tuberculoid granulomatous reaction and 1 patient with polypoid lesion with adenomyomatosis. CONCLUSIONS: FDG-PET may be of utility to establish the diagnosis of gallbladder cancer in patients with nonspecific clinical and imaging findings.