PET/CT of COVID-19 as an Organizing Pneumonia.

An 85-year-old woman with history of melanoma is referred for a follow-up F-FDG PET/CT. F-FDG PET/CT scan showed bilateral and peripheral ground-glass opacities in upper and lower pulmonary lobes surrounded by consolidations of crescent shape with increased FDG uptake, findings compatible with organizing pneumonia. Following further inquiry, the patient reported low-grade fever, sore throat, and fatigue for the past 6 days. Because of the ongoing COVID-19 pandemic, the patient was tested for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), which resulted positive.

Effectiveness of serological markers of eosinophil activity in monitoring eosinophilic esophagitis.

BACKGROUND: it is necessary to find serological markers accessible in clinical practice to prevent the need to perform repeated endoscopies. OBJECTIVE: to assess the efficacy of eosinophil activity markers in monitoring eosinophilic esophagitis (EoE). MATERIAL AND METHODS: thirty patients were included prospectively, all under dietary treatment -diets excluding 6 foods, and allergy test based diet (skin prick test and specific IgE). The variables assessed were demographic parameters, eosinophil cationic protein (ECP) levels (µg/mL), total IgE (KU/L), peripheral blood eosinophils (PBE) (U/mm³), and the maximum peak of eosinophils/hpf in esophageal biopsies. The variation found between these figures was assessed in line with response to dietary treatment. RESULTS: thirty patients (66.7% males; mean age 33.43 years) were included in the study, 22 responders and 8 non-responders. Ninety percent presented a personal history of atopy. No significant decrease was detected in serum total IgE and ECP after diet in responder and nonresponders. However, the PBE decreased significantly in responders but not in nonresponders, PBE in responders (pre-diet. 397.27 vs. post-diet 276.81, p = 0.024) and non-responders PBE (pre-diet. 460 vs. post-diet 317.5, p = 0.23). CONCLUSION: serum total IgE and ECP do not act as markers for EoE activity. However PBE may play a role in this regard, bearing in mind that this parameter may be influenced by concomitant atopic conditions.

[Usefulness of (18)F-fluorodeoxyglucose-positron emission tomography-computerized tomography in the identification of the primary tumor in patients with cancer of unknown origin]. / Utilidad de la tomografía por emisión de positrones con (18)F-fluorodesoxiglucosa-tomografía computarizada en la identificación del tumor primario en pacientes con cáncer de origen desconocido.

BACKGROUND AND OBJECTIVE: We determined the utility of the (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)-computerized tomography (CT) in the localization of the primary tumor in patients with tumor of unknown origin (TUO). PATIENTS AND METHOD: (18)F-FDG PET-CT scans, performed between November 2006 and November 2010, in search for the primary tumor in patients with TUO, were retrospectively evaluated. Patients underwent a standard PET-CT, 50-60minutes after intravenous injection of 296-370MBq (18)F-FDG. PET-CT studies were assessed as pathological, with/without identification of the primary tumour and no pathological. Final diagnosis was established by histological confirmation and/or clinical/radiologic follow-up longer than 6 months. RESULTS: We studied 74 patients (59 males, 15 females), with ages ranging from 41-89 years. In 38 (51%) patients the PET-CT assessed the correct origin of the primary tumour. In 8 cases, a histological confirmation in the primary lesion was obtained. In 4 patients the PET-CT showed a false positive result. CONCLUSION: PET-CT scanning identified 51% of the primary sites in our sample of patients.

Value of 4-dimensional 18F-FDG PET/CT in the classification of pulmonary lesions.

UNLABELLED: Our aim was to evaluate the effect of 4-dimensional (4D) (18)F-FDG PET/CT in the detection of pulmonary lesions. METHODS: Fifty-seven pulmonary lesions were prospectively assessed in 37 patients (26 men and 11 women) with a mean age of 66.3 y. Twenty-nine of these patients had a history of neoplasm. All patients underwent 3-dimensional (3D) total-body PET/CT and 4D thoracic PET/CT (synchronized with respiratory movement). Maximum standardized uptake value (SUVmax) was obtained for each lesion in both studies. For the 4D studies, we selected the SUVmax in the respiratory period with the highest uptake ("best bin") and the average value over all bins ("average gated"). SUVmax percentage difference between 3D and 4D PET/CT and the relationship of this value to the diameter and location of the lesions were calculated. Statistical parameters were calculated for 3D and 4D PET/CT. RESULTS: Fifty-four of 57 lesions showed an increase of SUVmax in the 4D study with respect to the 3D study. The mean SUVmax was 3.1 in the 3D study. 4D PET/CT studies showed a mean SUVmax of 4.5 for the best-bin study and 3.9 for the average gated study. The percentage difference in mean SUVmax between 3D and 4D studies (best bin and averaged gated) was 72.9% and 48.8%, respectively. The smaller the lesion, the greater was the SUVmax percentage difference (P < 0.05). However, no statistical differences dependent on the location of the lesions were observed. Final diagnosis showed that 37 lesions were malignant. The sensitivity, specificity, positive predictive value, and negative predictive value were 37.8%, 95%, 93%, and 45%, respectively, for 3D studies and 70.3%, 70%, 81.2%, and 56%, respectively, for 4D best-bin studies. CONCLUSION: Characterization of malignant lung lesions was better with 4D PET/CT than with standard PET/CT.

Impact of radioguided occult lesion localization on the correct excision of malignant breast lesions: effect of histology and tumor size.

AIM: To evaluate the impact of radioguided occult lesion localization (ROLL) in the correct location and excision of malignant breast lesions, and analyze if these results are affected by the histology and tumor size. MATERIALS AND METHODS: A total of 105 patients with occult breast lesions were studied. The mean age was 55 years. An intralesional dose of 18.5 MBq of 99mTc-labeled macroaggregated human albumin (AMA) was administered using stereotaxic mammography or ultrasound. Surgical resection was carried out with the help of a gammadetector probe. In the histological study, disease-free margin was defined by a distance between the tumor lesion and the surgical margin of more than 1 mm. The possible influence of tumor histology and lesion diameter with respect to free/affected margins was analyzed. RESULTS: Correct radiotracer placement was achieved in 100/105 of the cases (95.2%). In the remaining 5 cases (4.8%), radiotracer placement was incorrect, with 2 of them being malignant lesions that were found by macroscopic inspection, and the other 3 having benign pathology. Among the malignant lesions (44 cases), correct placement of the radiotracer was achieved in 42 cases (95.5%). Of these 42 malignant lesions, in which the ROLL was correctly performed, free surgical margins were obtained in 24 cases (57.1%), while the other 18 (42.9%) had infiltrated surgical margins. The most common histological type among the malignant lesions was invasive ductal carcinoma (71.4%). The histological types with an increased frequency of infiltration of surgical margins were invasive and microinvasive cancer (94.4%). All the affected margins were in lesions greater than 10 mm, and the highest incidence was in those between 20 and 30 mm (55.5%). CONCLUSION: In our experience, the advantages of the ROLL technique are a precise localization of malignant breast lesions (95.5%) and an increased probability of a complete excision with free margins in more than one half of them. Nevertheless, special consideration should be taken when dealing with invasive and microinvasive cancers and in those exceeding 10 mm because of their higher incidence of infiltrated margins.