Antibiotic Prophylaxis in Infants with Grade III, IV, or V Vesicoureteral Reflux.

BACKGROUND: The efficacy of continuous antibiotic prophylaxis in preventing urinary tract infection (UTI) in infants with grade III, IV, or V vesicoureteral reflux is controversial. METHODS: In this investigator-initiated, randomized, open-label trial performed in 39 European centers, we randomly assigned infants 1 to 5 months of age with grade III, IV, or V vesicoureteral reflux and no previous UTIs to receive continuous antibiotic prophylaxis (prophylaxis group) or no treatment (untreated group) for 24 months. The primary outcome was the occurrence of the first UTI during the trial period. Secondary outcomes included new kidney scarring and the estimated glomerular filtration rate (GFR) at 24 months. RESULTS: A total of 292 participants underwent randomization (146 per group). Approximately 75% of the participants were male; the median age was 3 months, and 235 participants (80.5%) had grade IV or V vesicoureteral reflux. In the intention-to-treat analysis, a first UTI occurred in 31 participants (21.2%) in the prophylaxis group and in 52 participants (35.6%) in the untreated group (hazard ratio, 0.55; 95% confidence interval [CI], 0.35 to 0.86; P = 0.008); the number needed to treat for 2 years to prevent one UTI was 7 children (95% CI, 4 to 29). Among untreated participants, 64.4% had no UTI during the trial. The incidence of new kidney scars and the estimated GFR at 24 months did not differ substantially between the two groups. Pseudomonas species, other non-Escherichia coli organisms, and antibiotic resistance were more common in UTI isolates obtained from participants in the prophylaxis group than in isolates obtained from those in the untreated group. Serious adverse events were similar in the two groups. CONCLUSIONS: In infants with grade III, IV, or V vesicoureteral reflux and no previous UTIs, continuous antibiotic prophylaxis provided a small but significant benefit in preventing a first UTI despite an increased occurrence of non-E. coli organisms and antibiotic resistance. (Funded by the Italian Ministry of Health and others; PREDICT ClinicalTrials.gov number, NCT02021006; EudraCT number, 2013-000309-21.).

The evidence-based role of catecholaminergic PET tracers in Neuroblastoma. A systematic review and a head-to-head comparison with mIBG scintigraphy.

BACKGROUND: Molecular imaging is pivotal in staging and response assessment of children with neuroblastoma (NB). [123I]-metaiodobenzylguanidine (mIBG) is the standard imaging method; however, it is characterised by low spatial resolution, time-consuming acquisition procedures and difficult interpretation. Many PET catecholaminergic radiotracers have been proposed as a replacement for [123I]-mIBG, however they have not yet made it into clinical practice. We aimed to review the available literature comparing head-to-head [123I]-mIBG with the most common PET catecholaminergic radiopharmaceuticals. METHODS: We searched the PubMed database for studies performing a head-to-head comparison between [123I]-mIBG and PET radiopharmaceuticals including meta-hydroxyephedrine ([11C]C-HED), 18F-18F-3,4-dihydroxyphenylalanine ([18F]DOPA) [124I]mIBG and Meta-[18F]fluorobenzylguanidine ([18F]mFBG). Review articles, preclinical studies, small case series (< 5 subjects), case reports, and articles not in English were excluded. From each study, the following characteristics were extracted: bibliographic information, technical parameters, and the sensitivity of the procedure according to a patient-based analysis (PBA) and a lesion-based analysis (LBA). RESULTS: Ten studies were selected: two regarding [11C]C-HED, four [18F]DOPA, one [124I]mIBG, and three [18F]mFBG. These studies included 181 patients (range 5-46). For the PBA, the superiority of the PET method was reported in two out of ten studies (both using [18F]DOPA). For LBA, PET detected significantly more lesions than scintigraphy in seven out of ten studies. CONCLUSIONS: PET/CT using catecholaminergic tracers shows superior diagnostic performance than mIBG scintigraphy. However, it is still unknown if such superiority can influence clinical decision-making. Nonetheless, the PET examination appears promising for clinical practice as it offers faster image acquisition, less need for sedation, and a single-day examination.

EANM practice guidelines for an appropriate use of PET and SPECT for patients with epilepsy.

Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy. In patients with drug-resistant focal epilepsy, epilepsy surgery is a treatment option depending on the localisation of the seizure focus for seizure relief or seizure freedom with consecutive improvement in quality of life. Beside examinations such as scalp video/electroencephalography (EEG) telemetry, structural, and functional magnetic resonance imaging (MRI), which are primary standard tools for the diagnostic work-up and therapy management of epilepsy patients, molecular neuroimaging using different radiopharmaceuticals with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) influences and impacts on therapy decisions. To date, there are no literature-based praxis recommendations for the use of Nuclear Medicine (NM) imaging procedures in epilepsy. The aims of these guidelines are to assist in understanding the role and challenges of radiotracer imaging for epilepsy; to provide practical information for performing different molecular imaging procedures for epilepsy; and to provide an algorithm for selecting the most appropriate imaging procedures in specific clinical situations based on current literature. These guidelines are written and authorized by the European Association of Nuclear Medicine (EANM) to promote optimal epilepsy imaging, especially in the presurgical setting in children, adolescents, and adults with focal epilepsy. They will assist NM healthcare professionals and also specialists such as Neurologists, Neurophysiologists, Neurosurgeons, Psychiatrists, Psychologists, and others involved in epilepsy management in the detection and interpretation of epileptic seizure onset zone (SOZ) for further treatment decision. The information provided should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals and imaging modalities.

Automatic assessment of body composition in children with lymphoma: results of a [18F]FDG-PET/MR study.

OBJECTIVES: To use Dixon-MR images extracted from [18F]FDG-PET/MR scans to perform an automatic, volumetric segmentation and quantification of body composition in pediatric patients with lymphoma. MATERIALS AND METHODS: Pediatric patients with lymphoma examined by [18F]FDG-PET/MR at diagnosis and restaging were included. At each time point, axial fat and water Dixon T1w images of the thighs were automatically segmented and muscle volume, subcutaneous, intramuscular, and intermuscular fat volume were quantified. The metabolic activity of the largest nodal lesion and of muscles and subcutaneous fat was recorded. The paired samples t-test and Spearman's correlation coefficient were applied to evaluate potential differences between the two time points and the relationship between metabolic and body composition metrics, respectively. By logistic regression analysis, the prognostic role of the investigated variables was assessed. The applied significance level was p < 0.05 for all analyses. RESULTS: Thirty-seven patients (mean age ± SD 14 ± 3-years-old; 20 females) matched the inclusion criteria. After chemotherapy (interval between the two PET/MR scans, 56-80 days; median 65 days), muscle volume significantly decreased (629 ± 259 cm3 vs 567 ± 243 cm3, p < 0.001) while subcutaneous, intramuscular and intermuscular fat increased (476 ± 255 cm3 vs 607 ± 254 cm3, p < 0.001; 63 ± 20 cm3 vs 76 ± 26 cm3, p < 0.001; 58 ± 19 cm3 vs 71 ± 23 cm3, p < 0.001); the metabolic activity of the main nodal lesion, muscles, and subcutaneous fat significantly decreased (p < 0.05, each). None of the examined variables acted as predictors of the response to treatment (p = 0.283). A strong correlation between BMI and subcutaneous fat volume at diagnosis (r = 0.675, p < 0.001) and restaging (r = 0.600, p < 0.001) emerged. CONCLUSIONS: The proposed method demonstrated that pediatric patients with lymphoma undergo muscle loss and an increase of subcutaneous fat during treatment. CLINICAL RELEVANCE STATEMENT: The proposed automatic and volumetric MR-based assessment of body composition in children with lymphoma can be used to monitor the effect of chemotherapy and may guide tailored exercise programs during chemotherapy. KEY POINTS: T1w Dixon images can be used for the automatic segmentation and quantification of body composition. Muscle and subcutaneous fat volume do not act as predictors of the response to treatment in children with lymphoma. Chemotherapy induces changes in body composition in children with lymphoma.

EANM procedural recommendations for managing the paediatric patient in diagnostic nuclear medicine.

PURPOSE: The manuscript aims to characterize the principles of best practice in performing nuclear medicine procedures in paediatric patients. The paper describes all necessary technical skills that should be developed by the healthcare professionals to ensure the best possible care in paediatric patients, as it is particularly challenging due to psychological and physical conditions of children. METHODS: We performed a comprehensive literature review to establish the most relevant elements of nuclear medicine studies in paediatric patients. We focused the attention to the technical aspects of the study, such as patient preparation, imaging protocols, and immobilization techniques, that adhere to best practice principles. Furthermore, we considered the psychological elements of working with children, including comforting and distraction strategies. RESULTS: The extensive literature review combined with practical conclusions and recommendations presented and explained by the authors summarizes the most important principles of the care for paediatric patient in the nuclear medicine field. CONCLUSION: Nuclear medicine applied to the paediatric patient is a very special and challenging area, requiring proper education and experience in order to be performed at the highest level and with the maximum safety for the child.

Joint EANM/SIOPE/RAPNO practice guidelines/SNMMI procedure standards for imaging of paediatric gliomas using PET with radiolabelled amino acids and [18F]FDG: version 1.0.

Positron emission tomography (PET) has been widely used in paediatric oncology. 2-Deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) is the most commonly used radiopharmaceutical for PET imaging. For oncological brain imaging, different amino acid PET radiopharmaceuticals have been introduced in the last years. The purpose of this document is to provide imaging specialists and clinicians guidelines for indication, acquisition, and interpretation of [18F]FDG and radiolabelled amino acid PET in paediatric patients affected by brain gliomas. There is no high level of evidence for all recommendations suggested in this paper. These recommendations represent instead the consensus opinion of experienced leaders in the field. Further studies are needed to reach evidence-based recommendations for the applications of [18F]FDG and radiolabelled amino acid PET in paediatric neuro-oncology. These recommendations are not intended to be a substitute for national and international legal or regulatory provisions and should be considered in the context of good practice in nuclear medicine. The present guidelines/standards were developed collaboratively by the EANM and SNMMI with the European Society for Paediatric Oncology (SIOPE) Brain Tumour Group and the Response Assessment in Paediatric Neuro-Oncology (RAPNO) working group. They summarize also the views of the Neuroimaging and Oncology and Theranostics Committees of the EANM and reflect recommendations for which the EANM and other societies cannot be held responsible.

Fully integrated [18F]FDG PET/MR in large vessel vasculitis.

BACKGROUND: The aim of this study is to evaluate the usefulness of [18F] fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) in large vessels vasculitis (LVV) patients. METHODS: We performed an observational retrospective study based on our records. Images were acquired on a PET/MR scanner using [18F]FDG-PET whole body imaging. For each PET scan, a qualitative analysis and a semi-quantitative measure using the maximum of the standardized uptake value (SUVmax) were performed. SUVmax measurements normalized to the liver uptake were categorized using a grading scale. Vessel's wall thickness (WT) was measured at five fixed points (inferior margin of T5, T9, T12, L3, thickest area [max WT]). RESULTS: Twenty-three LVV patients were included, 56.5% giant cells arteritis, 34.8% Takayasu's arteritis and 8.7% isolated aortitis, all Caucasian, mostly females (82%). We considered 32 PET scans for the LVV group (from a minimum of one to a maximum of three scans per patient) mainly during follow-up (29/32 scans), and 23 PET scans from a control group of non-metastatic malignancies patients. We found higher SUVmax compared to controls, in all sites, irrespective of clinical disease activity. Mean WT resulted higher in patients than in controls but was not correlated to SUVmax. Mean WT positively correlated with age in both cohorts, inversely correlated to disease duration, while no correlation with SUVmax was observed. The concordance between clinically active disease and PET hypermetabolism was poor (Cohen' κ=0.33). CONCLUSIONS: PET/MR is a safe imaging technique capable of detecting inflammation in aortic wall. Low radiological exposure of PET/MR should be considered especially in young women receiving follow-up studies.

Subclinical enthesopathy of the midfoot: could it be a peculiar feature in early psoriatic arthritis?

OBJECTIVES: Bone scintigraphy (BS) is a sensitive tool that provides functional imaging to evaluate bone abnormalities in psoriatic arthritis (PsA). Our aims were to analyse the prevalence of increased BS uptake in the midfoot of PsA patients and to evaluate whether BS midfoot abnormalities could herald ultrasonography (US) and x-ray lesions in the same site. METHODS: Out of 88 consecutive BS performed in patients with early musculoskeletal symptoms (January-December 2010) and retrospectively analysed, 32 exams were carried out on subjects 3 months after being diagnosed with PsA. These patients were included in a retrospective study and analysed for BS feet uptake. Their baseline x-rays of the feet were also retrieved. Five years after BS (January-December 2015) all 32 PsA patients underwent clinical evaluation, x-rays and US of the feet. Frequency and percentage of each imaging abnormality of the midfoot were analysed. Clinical, functional and laboratory indexes were collected and correlations between clinical and imaging parameters were studied. RESULTS: Of all 32 PsA patients, 21 (65.6%) had an increased BS uptake in the midfoot, without any baseline x-ray abnormalities. After 5 years, the x-rays and US were able to detect ≥1 lesion in the midfoot of 14/32 (43.8%) and 28/32 (87.5%) patients, respectively. A high prevalence of enthesophytes in all 64 midfeet was shown by both x-rays (40.6%) and US (81.6%). We found a higher prevalence of structural lesions in the subgroup with BS positive midfoot compared with BS negative patients: x-rays [10/21 (47.6%) vs. 4/11 (36.4%); p=0.04] and US [19/21 (90.5%) vs. 8/11 (72.7%); p=0.04]. CONCLUSIONS: Midfoot involvement is frequent in PsA. BS increased uptake in the midfoot seems to be an early sign of the disease.

PET/MRI in prostate cancer: a systematic review and meta-analysis.

AIM: In recent years, the clinical availability of scanners for integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) has enabled the practical potential of multimodal, combined metabolic-receptor, anatomical, and functional imaging to be explored. The present systematic review and meta-analysis summarize the diagnostic information provided by PET/MRI in patients with prostate cancer (PCa). MATERIALS AND METHODS: A literature search was conducted in three different databases. The terms used were "choline" or "prostate-specific membrane antigen - PSMA" AND "prostate cancer" or "prostate" AND "PET/MRI" or "PET MRI" or "PET-MRI" or "positron emission tomography/magnetic resonance imaging." All relevant records identified were combined, and the full texts were retrieved. Reports were excluded if (1) they did not consider hybrid PET/MRI; or (2) the sample size was < 10 patients; or (3) the raw data were not enough to enable the completion of a 2 × 2 contingency table. RESULTS: Fifty articles were eligible for systematic review, and 23 for meta-analysis. The pooled data concerned 2104 patients. Initial disease staging was the main indication for PET/MRI in 24 studies. Radiolabeled PSMA was the tracer most frequently used. In primary tumors, the pooled sensitivity for the patient-based analysis was 94.9%. At restaging, the pooled detection rate was 80.9% and was higher for radiolabeled PSMA than for choline (81.8% and 77.3%, respectively). CONCLUSIONS: PET/MRI proved highly sensitive in detecting primary PCa, with a high detection rate for recurrent disease, particularly when radiolabeled PSMA was used.

Oral steroids for reducing kidney scarring in young children with febrile urinary tract infections: the contribution of Bayesian analysis to a randomized trial not reaching its intended sample size.

BACKGROUND: This study aimed to evaluate the effect of oral dexamethasone in reducing kidney scars in infants with a first febrile urinary tract infection (UTI). METHODS: Children aged between 2 and 24 months with their first presumed UTI, at high risk for kidney scarring based on procalcitonin levels (≥1 ng/mL), were randomly assigned to receive dexamethasone in addition to routine care or routine care only. Kidney scars were identified by kidney scan at 6 months after initial UTI. Projections of enrollment and follow-up completion showed that the intended sample size could not be reached before funding and time to complete the study ran out. An amendment to the protocol was approved to conduct a Bayesian analysis. RESULTS: We randomized 48 children, of whom 42 had a UTI and 18 had outcome kidney scans (instead of 128 planned). Kidney scars were found in 0/7 and 2/11 patients in the treatment and control groups respectively. The probability that dexamethasone could prevent kidney scarring was 99% in the setting of an informative prior probability distribution (which fully incorporated in the final inference the information on treatment effect provided by previous studies) and 98% in the low-informative scenario (which discounted the prior literature information by 50%). The probabilities that dexamethasone could reduce kidney scar formation by up to 20% were 61% and 53% in the informative and low-informative scenario, respectively. CONCLUSIONS: Dexamethasone is highly likely to reduce kidney scarring, with a more than 50% probability to reduce kidney scars by up to 20%. TRIAL REGISTRATION NUMBER: EudraCT number: 2013-000388-10; registered in 2013 (prospectively registered) A higher resolution version of the Graphical abstract is available as Supplementary information.

Transcutaneous near-infrared spectroscopy (NIRS) for monitoring kidney and liver allograft perfusion.

BACKGROUND: The use of transcutaneous near-infrared spectroscopy (NIRS) for monitoring the perfusion of kidney and liver allografts has been proposed in the last years. This device might detect an early decrease in allograft oxygenation allowing prompt detection of vascular complications. METHODS: A systematic review of the literature about the use of transcutaneous NIRS in monitoring allograft perfusion was performed according to the PRISMA guidelines. RESULTS: The authors screened 1313 papers. The search yielded five pertinent articles. Three of them reported the experience of NIRS in kidney transplantation and the other two dealt with its use in liver transplantation, for a total of 55 paediatric patients and 121 adults. In the studies concerning kidney transplantation, NIRS measurements were significantly related to serum creatinine, estimated glomerular filtration rate (eGFR), urinary neutrophil gelatinase-associated lipocalin (u-NGAL), serum lactate, resistive index assessed by Doppler-ultrasonography and systolic blood pressure. The two studies dealing with liver transplantation found a significant decrease in liver regional oxygenation, assessed by NIRS, before the occurrence of vascular complications. CONCLUSIONS: Preliminary studies have related NIRS monitoring to kidney and liver allograft perfusion, both in adults and children. Further investigation is needed to establish the normal range of NIRS values and the factors influencing NIRS monitoring.

Volumetric histograms-based analysis of apparent diffusion coefficients and standard uptake values for the assessment of pediatric sarcoma at staging: preliminary results of a PET/MRI study.

PURPOSE: To assess the relationship between apparent diffusion coefficients (ADC) and standard uptake values (SUV) of pediatric sarcomas at staging by using volumetric histograms analyses. METHODS: Children with histologically proven sarcoma, referring to our tertiary center for a whole-body 18F-FDG PET/MRI for staging and including diffusion weighted imaging in the MRI protocol were investigated. Firstly, turbo inversion recovery magnitude (TIRM) and PET images were resliced and resampled according to the ADC maps. Regions of interests were drawn along tumor margins on TIRM images and then copied on PET and ADC datasets. Pixel-based SUVs and ADCs were collected from the entire volume of each lesion. Mean, median, skewness, and kurtosis of SUVs and ADCs values were computed, and the Pearson correlation coefficient was then applied (for the entire population and for histological subgroups with more than five patients). RESULTS: Thirteen patients met the inclusion criteria (six females; mean age 8.31 ± 6.03 years). Histology revealed nine rhabdomyosarcomas, three Ewing sarcomas, and one chondroblastic osteosarcoma. A significant negative correlation between ADCs' and SUVs' mean (rmean = - 0.501, P < 0.001), median (rmedian = - 0.519, P < 0,001), and skewness (rskewness = - 0.550, P < 0.001) emerged for the entire population and for rhabdomyosarcomas (rmean = - 0.541, P = 0.001, rmedian = - 0.597, P < 0.001, rskewness = - 0.568, P < 0.001), whereas a significant positive correlation was found for kurtosis (rkurtosis = 0.346, P < 0.001, and rkurtosis = 0.348, P < 0.001 for the entire population and for rhabdomyosarcomas, respectively). CONCLUSION: Our preliminary results demonstrate that, using volumetric histograms, simultaneously collected SUVs and ADCs are dependent biomarkers in pediatric FDG-avid sarcomas. Further studies, on a larger population, are necessary to confirm this evidence and assess its clinical implications.

18F-FDG PET/MRI for Rectal Cancer TNM Restaging After Preoperative Chemoradiotherapy: Initial Experience.

OBJECTIVE: F-FDG-PET/MRI is a novel hybrid techinque that has been recently introduced in oncological imaging, showing promising results. The aim of this study is to assess the value of whole-body F-FDG-PET/MRI for predicting the pathological stage of locally advanced rectal cancer after preoperative chemoradiotherapy. DESIGN: This was a prospective observational study. SETTINGS: The study was conducted at a tertiary care hospital. PATIENTS: Thirty-six patients with locally advanced rectal cancer (25 male, median age 68.5 years) were prospectively assessed with PET/MRI and thoracoabdominal CT before and after preoperative chemoradiotherapy. Twenty-seven patients underwent low anterior or abdominoperineal resection. Nine patients with a complete clinical response underwent organ-preserving treatment (8 local excision and 1 watch-and-wait approach) with >1-year follow-up. MAIN OUTCOME MEASURES: One radiologist evaluated pelvic MRI and CT. A second radiologist and a nuclear medicine physician jointly assessed PET/MRI. The imaging was compared with histology or follow-up (ypT0 vs T ≥1 and ypN0 vs ypN+ categories). Metastases were confirmed with biopsy or a follow-up CT scan at least at 1 year after preoperative chemoradiotherapy. The sensitivity, specificity, and accuracy values of the imaging techniques were calculated using standard formulas. RESULTS: The accuracy for ypT staging was 89% and 92%, and the accuracy for ypN was 86% and 92% for MRI and PET/MRI. Compared with CT, PET/MRI correctly diagnosed 4 of 5 metastases, but it did not detect a lung metastatic nodule. In 11% of the patients, the PET/MRI changed the treatment strategy. LIMITATIONS: This study is limited by its small sample size. CONCLUSIONS: Although the whole-body PET/MRI was more accurate than the pelvic MRI alone for the prediction of tumor and node response to preoperative chemoradiotherapy, the technique performed worse than CT in detecting small lung metastasis. See Video Abstract at http://links.lww.com/DCR/B108. TOMOGRAFÍA POR EMISIÓN DE POSITRONES DE 18F- FLUORODEOXIGLUCOSA (FDG) / RESONANCIA MAGNÉTICA (TEP/RM) PARA ESTADIFICACIÓN TUMORAL TNM DE CÁNCER DEL RECTO DESPUÉS DE LA QUIMIORRADIOTERAPIA PREOPERATORIA - EXPERIENCIA INICIAL: Evaluar el valor de la tomografía por emisión de positrones de 18F-fluorodeoxiglucosa / resonancia magnética (TEP/RM) para predecir el estadio patológico del cáncer de recto localmente avanzado después de la quimiorradioterapia preoperatoria.Este fue un estudio prospectivo observacional.El estudio se realizó en un hospital de atención terciaria.Treinta y seis pacientes con cáncer rectal localmente avanzado (25 hombres, edad media de 68.5 años) fueron evaluados prospectivamente con TEP/RM y tomografía computarizada (TC) toraco-abdominal antes y después de la quimiorradioterapia preoperatoria. Veintisiete pacientes se sometieron a resección anterior baja o abdominoperineal. Nueve pacientes con una respuesta clínica completa se sometieron a un tratamiento de preservación de órganos (8 escisión local y 1 un enfoque de observar y esperar) con un seguimiento de> 1 año.Un radiólogo evaluó la RM pélvica y la TC. Un segundo radiólogo y un médico de medicina nuclear evaluaron conjuntamente TEP / RM. La imagen se comparó con la histología o el seguimiento (ypT0 vs T ≥1 y ypN0 vs ypN + categorías). Las metástasis se confirmaron con biopsia o una TC de seguimiento al menos 1 año después de la quimiorradioterapia preoperatoria. Los valores de sensibilidad, especificidad y precisión de las técnicas de imagen se calcularon utilizando fórmulas estándar.La precisión para la estadificación ypT fue del 89% y 92%, y la precisión para ypN fue del 86% y 92% para RM y TEP/RM respectivamente. En comparación con la TC, la TEP / RM diagnosticó correctamente 4 de 5 metástasis, pero no detectó un nódulo metastásico pulmonar. En el 11% de los pacientes, la TEP / RM cambió la estrategia de tratamiento.Este estudio está limitado por su pequeño tamaño de muestra.Si bien la TEP / RM de todo el cuerpo fue más precisa que la RM pélvica sola para la predicción de la respuesta tumoral y ganglionar a la quimiorradioterapia preoperatoria, la técnica funcionó peor que la TC para detectar metástasis pulmonares pequeños. Consulte Video Resumen en http://links.lww.com/DCR/B108.

FDG PET in response evaluation of bulky masses in paediatric Hodgkin's lymphoma (HL) patients enrolled in the Italian AIEOP-LH2004 trial.

PURPOSE: We present the results of an investigation of the role of FDG PET in response evaluation of bulky masses in paediatric patients with Hodgkin's lymphoma (HL) enrolled in the Italian AIEOP-LH2004 trial. METHODS: We analysed data derived from 703 patients (388 male, 315 female; mean age 13 years) with HL and enrolled in 41 different Italian centres from March 2004 to September 2012, all treated with the AIEOP-LH2004 protocol. The cohort comprised 309 patients with a bulky mass, of whom 263 were evaluated with FDG PET at baseline and after four cycles of chemotherapy. Responses were determined according to combined functional and morphological criteria. Patients were followed up for a mean period of 43 months and for each child we calculated time-to-progression (TTP) and relapse rates considering clinical monitoring, and instrumental and histological data as the reference standard. Statistical analyses were performed for FDG PET and morphological responses with respect to TTP. Multivariate analysis was used to define independent predictive factors. RESULTS: Overall, response evaluation revealed 238 PET-negative patients (90.5%) and 25 PET-positive patients (9.5%), with a significant difference in TTP between these groups (mean TTP: 32.67 months for negative scans, 23.8 months for positive scans; p < 0.0001, log-rank test). In the same cohort, computed tomography showed a complete response (CR) in 85 patients (32.3%), progressive disease (PD) in 6 patients (2.3%), and a partial response (PR) in 165 patients (62.7%), with a significant difference in TTP between patients with CR and patients with PD (31.1 months and 7.9 months, respectively; p < 0.001, log-rank test). Similarly, there was a significant difference in relapse rates between PET-positive and PET-negative patients (p = 0000). In patients with PR, there was also a significant difference in TTP between PET-positive and PET-negative patients (24.6 months and 34.9 months, respectively; p < 0.0001). In the multivariate analysis with correction for multiple testing, only the PET result was an independent predictive factor in both the entire cohort of patients and the subgroup showing PR on CT (p < 0.01). CONCLUSION: After four cycles of chemotherapy, FDG PET response assessment in paediatric HL patients with a bulky mass is a good predictor of TTP and disease outcome. Moreover, in patients with a PR on CT, PET was able to differentiate those with a longer TTP. In paediatric HL patients with a bulky mass and in patients with a PR on CT, response on FDG PET was an independent predictive factor.

Whole-body low-dose CT recognizes two distinct patterns of lytic lesions in multiple myeloma patients with different disease metabolism at PET/MRI.

We evaluated differences in density and 18F-FDG PET/MRI features of lytic bone lesions (LBLs) identified by whole-body low-dose CT (WB-LDCT) in patients affected by newly diagnosed multiple myeloma (MM). In 18 MM patients, 135 unequivocal LBLs identified by WB-LDCT were characterized for inner density (negative or positive Hounsfield unit (HU)), where negative density (HU < 0) characterizes normal yellow marrow whereas positive HU correlates with tissue-like infiltrative pattern. The same LBLs were analyzed by 18F-FDG PET/DWI-MRI, registering DWI signal with ADC and SUV max values. According to HU, 35 lesions had a negative density (- 56.94 ± 31.87 HU) while 100 lesions presented positive density (44.87 ± 23.89 HU). In seven patients, only positive HU LBLs were demonstrated whereas in eight patients, both positive and negative HU LBLs were detected. Intriguingly, in three patients (16%), only negative HU LBLs were shown. At 18F-FDG PET/DWI-MRI analysis, negative HU LBLs presented low ADC values (360.69 ± 154.38 × 10-6 mm2/s) and low SUV max values (1.69 ± 0.56), consistent with fatty marrow, whereas positive HU LBLs showed an infiltrative pattern, characterized by higher ADC (mean 868.46 ± 207.67 × 10-6 mm2/s) and SUV max (mean 5.04 ± 1.94) values. Surprisingly, histology of negative HU LBLs documented infiltration by neoplastic plasma cells scattered among adipocytes. In conclusion, two different patterns of LBLs were detected by WB-LDCT in MM patients. Both types of lesions were indicative for active disease, although only positive HU LBL were captured by 18F-FDG PET/DWI-MRI imaging, indicating that WB-LDCT adds specific information.

A new integrated dual time-point amyloid PET/MRI data analysis method.

PURPOSE: In the initial evaluation of patients with suspected dementia and Alzheimer's disease, there is no consensus on how to perform semiquantification of amyloid in such a way that it: (1) facilitates visual qualitative interpretation, (2) takes the kinetic behaviour of the tracer into consideration particularly with regard to at least partially correcting for blood flow dependence, (3) analyses the amyloid load based on accurate parcellation of cortical and subcortical areas, (4) includes partial volume effect correction (PVEC), (5) includes MRI-derived topographical indexes, (6) enables application to PET/MRI images and PET/CT images with separately acquired MR images, and (7) allows automation. METHODS: A method with all of these characteristics was retrospectively tested in 86 subjects who underwent amyloid (18F-florbetaben) PET/MRI in a clinical setting (using images acquired 90-110 min after injection, 53 were classified visually as amyloid-negative and 33 as amyloid-positive). Early images after tracer administration were acquired between 0 and 10 min after injection, and later images were acquired between 90 and 110 min after injection. PVEC of the PET data was carried out using the geometric transfer matrix method. Parametric images and some regional output parameters, including two innovative "dual time-point" indexes, were obtained. RESULTS: Subjects classified visually as amyloid-positive showed a sparse tracer uptake in the primary sensory, motor and visual areas in accordance with the isocortical stage of the topographic distribution of the amyloid plaque (Braak stages V/VI). In patients classified visually as amyloid-negative, the method revealed detectable levels of tracer uptake in the basal portions of the frontal and temporal lobes, areas that are known to be sites of early deposition of amyloid plaques that probably represented early accumulation (Braak stage A) that is typical of normal ageing. There was a strong correlation between age and the indexes of the new dual time-point amyloid imaging method in amyloid-negative patients. CONCLUSIONS: The method can be considered a valuable tool in both routine clinical practice and in the research setting as it will standardize data regarding amyloid deposition. It could potentially also be used to identify early amyloid plaque deposition in younger subjects in whom treatment could theoretically be more effective.

Homonymous Hemianopsia Due to Posterior Cortical Atrophy.

A 63-year-old woman presented to her ophthalmologist complaining of reading difficulties for two years. Ophthalmological examination revealed a homonymous hemianopsia. Brain magnetic resonance imaging (MRI) scan was interpreted as normal, but positron emission tomography (PET) showed areas of posterior brain hypometabolism. This case highlights the high diagnostic suspicion that ophthalmologists should have regarding posterior cortical atrophy (including the visual variant of Alzheimer disease) in patients complaining of reading difficulties in the setting of a normal ophthalmic examination.

Renal transplantation in children weighing <15 kg: does concomitant lower urinary tract dysfunction influence the outcome?

BACKGROUND: We reviewed our experience with renal transplantation (RTx) in children weighing <15 kg to determine if the presence of lower urinary tract dysfunction (LUTD) influenced the outcome. METHODS: Between 1987 and 2012, 68 RTx were performed in patients weighing less than 15 kg, including 17 with associated LUTD and 51 without. We detailed the lower urinary tract management in these patients, and compared graft survival rates and estimated clearance 12 and 60 months after RTx between groups. RESULTS: None of the patients without LUTD required any lower urinary tract surgery vs 8 out of 17 (47 %) with LUTD (p = 0.0001). The latter included a temporary incontinent urinary diversion in 5 cases (29 %), namely 2 vesicostomies and 3 cutaneous ureterostomies. After comparable follow-ups, there was no difference in patient survival, graft survival, and glomerular filtration rates between groups. CONCLUSIONS: Provided that there is appropriate bladder management, a concomitant LUTD does not adversely influence the outcome of RTx in patients weighing less than 15 kg. However, 50 % of our patients required lower urinary tract reconstruction and, in 30 %, a temporary incontinent urinary diversion was placed at RTx, since lower urinary tract function could not be assessed reliably, the patient was not collaborative enough to be involved in a voiding program, and/or the RTx was prioritized.