Dexamethasone to prevent kidney scarring in acute pyelonephritis: a randomized clinical trial.

BACKGROUND: Urinary tract infection (UTI) is one of the most common bacterial infections in childhood and is associated with long-term complications. We aimed to assess the effect of adjuvant dexamethasone treatment on reducing kidney scarring after acute pyelonephritis (APN) in children. METHODS: Multicenter, prospective, double-blind, placebo-controlled, randomized clinical trial (RCT) where children from 1 month to 14 years of age with proven APN were randomly assigned to receive a 3-day course of either an intravenous corticosteroid (dexamethasone 0.30 mg per kg/day) twice daily or placebo. The late technetium 99 m-dimercaptosuric acid scintigraphy (> 6 months after acute episode) was performed to assess kidney scar persistence. Kidney scarring risk factors (vesicoureteral reflux, kidney congenital anomalies, or urinary tract dilatation) were also assessed. RESULTS: Ninety-one participants completed the follow-up and were finally included (dexamethasone n = 49 and placebo n = 42). Both groups had similar baseline characteristics. Twenty participants showed persistent kidney scarring after > 6 months of follow-up without differences in incidence between groups (22% and 21% in the dexamethasone and placebo groups, p = 0.907). Renal damage severity in the early DMSA (ß = 0.648, p = 0.023) and procalcitonin values (ß = 0.065 p = 0.027) significantly modulated scar development. Vesicoureteral reflux grade showed a trend towards significance (ß = 0.545, p = 0.054), but dexamethasone treatment showed no effect. CONCLUSION: Dexamethasone showed no effect on reducing the risk of scar formation in children with APN. Hence, there is no evidence for an adjuvant corticosteroid treatment recommendation in children with APN. However, the study was limited by not achieving the predicted sample size and the expected scar formation. TRIAL REGISTRATION: Clinicaltrials.gov, NCT02034851. Registered in January 14, 2014. "A higher resolution version of the Graphical abstract is available as Supplementary information."

Incidental focal uptake in colorectal location on oncologic FDG PET and PET/CT studies: Histopathological findings and clinical significances / Captación focal incidental de 18F-FDG en colon en los estudios PET y PET/TAC: Hallazgos histopatológicos y significado clínico

Purpose: Unexpected focal colonic or rectal radiotracer activity is an usual finding in patients subjected to a PET study. The aim of this work has been to evaluate the clinical significance of this finding in the prediction of an existing colorectal malignancy. Material and methods: During the last three years, all patients studied with 18F-FDG PET/CT and PET for oncologic work-up purposes were prospectively surveyed for focal colorectal radiotracer activity. Colonoscopy was performed in all patients with this incidental finding in order to exclude colonic malignancy. CEA level, maximum standardized uptake value (SUVmax), CT findings, colonoscopy findings and histopathological results were prospectively analyzed in all patients. Results: A total of 2290 patients were evaluated, 158 of whom were studied with PET and the remainder with a hybrid PET/CT. Focal FDG colorectal activity was incidentally detected in 27 patients with no previous history of colorectal cancer. Colorectal adenocarcinoma was diagnosed in seven (25.9%) patients. A pre-cancerous lesion was found in eleven patients (40.7%). Eight patients (29.6%) had no macroscopic lesions. One patient was diagnosed with a benign lesion. Any focal activity found in the colon by 18F-FDG PET/CT examination predicts a probability greater than 50% of an underlying malignant or premalignant lesion in the histopathological analysis (logistic regression, p = 0.01), independently of the calculated SUVmax. Conclusion: According to the results of the present study, we recommend the performance of a colonoscopy and biopsy of any suspicious lesions, in all patients with unexpected focal FDG activity found in colon or rectum during a 18F-FDG PET/CT examination (AU)

Objetivo: La actividad focal incidental de FDG en colon o recto es un hallazgo usual en pacientes sometidos a una PET. El objetivo de este trabajo es evaluar el significado clínico que tiene este hallazgo en la predicción de la existencia de una lesión colorectal maligna. Material y métodos: Durante los últimos tres años todos los pacientes estudiados mediante PET/CT con 18F con fines oncológicos fueron valorados de forma prospectiva en busca de actividad focal colónica o rectal. Se realizó colonoscopia a todos los pacientes con este hallazgo, para excluir enfermedad maligna. Tanto los hallazgos de la colonoscopia, como los niveles de CEA, SUVmáx, hallazgos TAC y los resultados histopatológicos fueron prospectivamente analizados en todos ellos. Resultados: Un total de 2290 pacientes fueron evaluados, 158 de ellos fueron estudiados con PET y el resto con un equipo híbrido PET/TAC. En 27 de ellos se halló actividad focal de FDG sospechosa en colon o recto. En siete (25,9%) pacientes se diagnóstico adenocarcinoma colorectal. En 11 pacientes (40,7%) se halló una lesión precancerosa. Ocho pacientes (29,6%) no presentaron ninguna lesión macroscópicamente apreciable en la colonoscopia. Un paciente fue diagnosticado de una lesión benigna. Cualquier actividad focal de FDG predice una probabilidad mayor del 50% de corresponder a una lesión premaligna o maligna en el análisis histopatológico (regresión logística, p=0,01), independientemente del SUVmáx. Conclusión: De acuerdo con los resultados del presente estudio recomendamos la realización de una colonoscopia y biopsia de cualquier lesión sospechosa en todos los pacientes en los que se observe actividad focal de FDG en colon o recto en los estudios PET/TAC (AU)

Incidental focal uptake in colorectal location on oncologic ¹8FDG PET and PET/CT studies: histopathological findings and clinical significances.

PURPOSE: Unexpected focal colonic or rectal radiotracer activity is an usual finding in patients subjected to a PET study. The aim of this work has been to evaluate the clinical significance of this finding in the prediction of an existing colorectal malignancy. MATERIAL AND METHODS: During the last three years, all patients studied with (18)F-FDG PET/CT and PET for oncologic work-up purposes were prospectively surveyed for focal colorectal radiotracer activity. Colonoscopy was performed in all patients with this incidental finding in order to exclude colonic malignancy. CEA level, maximum standardized uptake value (SUVmax), CT findings, colonoscopy findings and histopathological results were prospectively analyzed in all patients. RESULTS: A total of 2290 patients were evaluated, 158 of whom were studied with PET and the remainder with a hybrid PET/CT. Focal FDG colorectal activity was incidentally detected in 27 patients with no previous history of colorectal cancer. Colorectal adenocarcinoma was diagnosed in seven (25.9%) patients. A pre-cancerous lesion was found in eleven patients (40.7%). Eight patients (29.6%) had no macroscopic lesions. One patient was diagnosed with a benign lesion. Any focal activity found in the colon by (18)F-FDG PET/CT examination predicts a probability greater than 50% of an underlying malignant or premalignant lesion in the histopathological analysis (logistic regression, p=0.01), independently of the calculated SUVmax. CONCLUSION: According to the results of the present study, we recommend the performance of a colonoscopy and biopsy of any suspicious lesions, in all patients with unexpected focal FDG activity found in colon or rectum during a (18)F-FDG PET/CT examination.

Focal splenic FDG uptake in a patient with Kala-Azar (visceral leishmaniasis).

We present a woman with a history of Gaucher disease and secondary portal hypertension. She went to hospital for treatment of resistant fever without apparent cause. A conventional study of fever of unknown origin did not show any pathology. For this reason, she was referred to our department for a PET/CT, which did not demonstrate a cause for the fever. Two months after, she was admitted again in hospital for fever recurrence. A new PET/CT showed FDG avid hypodense splenic lesions, suspicious for infection. Splenectomy was performed and histopathologic analysis demonstrated intracellular organisms compatible with Leishmania.

Assessment of rhabdoid brain tumor by F-18 FDG PET, C-11 methionine PET and MRI.

A 28-year-old man with headache, nausea, and decreased vision had a left parieto-occipital tumor demonstrated by MRI. Postradical resection and histology showed a solid mass containing rhabdoid cells, 10% positive for Ki-67. After completing chemotherapy and radiotherapy treatment, follow-up MRI revealed possible tumoral recurrence. Cerebral F-18 FDG PET revealed no pathologic uptake, and C-11 methionine PET showed a pathologic low uptake. These findings suggested recurrence of a mild-grade aggressiveness tumor, which was confirmed by a second neurosurgical resection.

Left ventricular end-diastolic volume is decreased at maximal exercise in athletes with marked repolarisation abnormalities: a continuous radionuclide monitoring study.

PURPOSE: Although marked repolarisation abnormalities (MRAs) are considered innocuous in trained athletes, their functional significance awaits clarification. The aim of this study was to further evaluate the pathophysiological implications of such MRAs. METHODS: We compared left ventricular (LV) functional response to exhausting exercise in 39 male athletes with (n=22) or without (n=17) MRAs and with no structural cardiac abnormalities, by means of a portable radionuclide monitoring system (Vest, Capintec, Inc., Ramsey, NJ). MRAs were defined by the presence of negative T waves > or =2 mm in three or more rest ECG leads. The Vest data were averaged for 30 s and analysed at baseline and at different heart rate (HR) values (50%, 75%, 85%, 95% and 100% of peak HR), as well as at 2, 5 and 10 min of recovery. RESULTS: There were no significant differences in the effect of exhausting exercise between athletes with and athletes without MRAs. However, there was a significant difference in the trend in end-diastolic volume (EDV) during exercise depending upon the group of athletes considered (p=0.05). EDV differed significantly between the two groups of athletes at peak HR (p=0.031). EDV in athletes with MRAs was lower than that in athletes without MRAs (102%+/-7% vs 107%+/-8%, p=0.034). CONCLUSION: EDV is decreased at peak HR in athletes with MRAs. Such high HR values are infrequently achieved or maintained during sporting activities; therefore, in the absence of structural heart disease, MRAs should not preclude physical training and competitive availability.

Challenging the neuronal MIBG uptake by pharmacological intervention: effect of a single dose of oral amitriptyline on regional cardiac MIBG uptake.

PURPOSE: Imaging with metaiodobenzylguanidine (MIBG) is used for the assessment of neuronal dysfunction in various cardiovascular disorders. Although valuable information is obtained by resting MIBG imaging, it is conceivable that competitive interference with the re-uptake mechanism would exaggerate MIBG defects and might unmask subclinical neuronal dysfunction. Tricyclic antidepressants, such as amitriptyline, have been reported to significantly increase cardiac MIBG washout and inhibit uptake into presynaptic neurons. This study was undertaken to assess whether a single oral dose of amitriptyline could influence cardiac MIBG distribution. METHODS: Six patients (aged 62-81 years; four males, two females) who had demonstrated a normal cardiac MIBG scan during work-up for movement disorders were studied. The patients underwent a second 123I-MIBG study after oral administration of 25 mg amitriptyline within 1 week. Single-photon emission computed tomography images were acquired at 4 h to assess the regional distribution of MIBG, after generation of polar maps and employing a 20-segment model. Mean percentage of peak activity was calculated for each segment at rest and after amitriptyline administration. RESULTS: After amitriptyline administration, there was a decrease in regional MIBG uptake in 10+/-4 segments per patient [62/120 segments (52%): 37 segments with a 5-10% decrease, 25 segments with a >10% decrease]. This change was statistically significant in lateral (P=0.003), apical (P<0.0001) and inferior (P=0.03) regions. CONCLUSION: A single oral dose of amitriptyline can induce changes in the uptake and retention of cardiac MIBG, indicating the feasibility of use of pharmacological intervention in cardiac neurotransmission imaging.

99mTc-depreotide scintigraphy of bone lesions in patients with lung cancer.

PURPOSE: Scintigraphy with 99mTc-depreotide, a somatostatin analogue-technetium ligand, has been used for evaluation of various malignant neoplasms, including lung cancer. The diagnosis of bone metastases in patients with lung cancer is not always definitive with current imaging methods. Visualisation of somatostatin receptors (SSTRs) in bone lesions, when the primary tumour exhibits such receptors, could be helpful in characterising them as metastatic. The aim of this study was to assess the value of 99mTc-depreotide in differentiating between benign and malignant bone lesions in patients with lung cancer. METHODS: The study population comprised 20 patients (17 males and three females, mean age 63 years) with proven lung cancer in whom bone lesions had been detected by conventional imaging methods. All patients underwent 99mTc-hydroxydiethylene diphosphonate and 99mTc-depreotide scintigraphy within 2 weeks. Bone lesions were classified as benign or malignant on the basis of clinical, imaging and/or histological criteria. RESULTS: 99mTc-depreotide uptake in the primary tumour was seen in 19 of the 20 patients. Conventional imaging methods detected 55 bone lesions, 31 of which were classified as malignant. Twenty-eight (90%) of these lesions showed 99mTc-depreotide uptake, suggesting bone metastases, while three did not. Twenty-four bone lesions were classified as benign by conventional imaging methods, and none of them showed 99mTc-depreotide uptake. In addition, 99mTc-depreotide demonstrated extra-osseous lesions in six patients. CONCLUSION: In patients with lung cancer and bone lesions, 99mTc-depreotide scintigraphy uptake in the bone lesions supports the diagnosis of malignancy, in particular if the primary lung tumour also exhibits SSTRs. Furthermore, whole-body 99mTc-depreotide scintigraphy may disclose extra-osseous disease.