Calibración de PET/TC para adquisición de estudio de cuerpo estándar postratamiento con esferas de resina de ytrio-90 / PET/CT calibration for post-treatment standard body scan acquisition with yttrium-90 Resin Micro-SPHERES

Introducción Entre los objetivos en los tratamientos con esferas marcadas con ytrio-90 figura demostrar que se consigue la dosis tumoricida y que se evitan dosis hepatotóxicas, así como que no existe deposición extrahepática. Material y métodos Utilizamos diferentes cantidades de ytrio y un maniquí NEMA NU2-2007 para comprobar si el tomógrafo mantiene una respuesta que permita hacer cálculos dosimétricos reales. Resultados El tomógrafo Gemini responde de manera lineal en un rango amplio de actividades con una R2=0,9983. Conclusión La capacidad de detección del equipo PET nos permite realizar estudios de cuerpo estándar con finalidad dosimétrica con tiempos de 5min por BED, que además hacen posible verificar la ausencia de deposición extrahepática de cantidades significativas de esferas de ytrio-90 (AU)

Introduction Among the objectives in treatments with yttrium-90 spheres is to demonstrate that the tumoricidal dose is achieved and that hepatotoxic doses are avoided, as well as that there is no extrahepatic deposition. Material and methods We use different amounts of yttrium-90 resin micro-spheres and a NEMA NU2-2007 phantom to check if the scanner maintains a response that allows real dosimetric calculations. Results The Gemini tomograph responds linearly in a wide range of activities with R2=0.9983. Conclusion The detection capacity of the PET equipment allows us to carry out standard body studies with dosimetric purposes with times of five minutes per BED. It also make possible to verify the absence of extrahepatic deposition of significant amounts of yttrium 90 spheres (AU)

PET/CT calibration for post-treatment standard body scan acquisition with yttrium-90 resin micro-SPHERES.

INTRODUCTION: Among the objectives in treatments with yttrium-90 spheres, is to demonstrate that the tumoricidal dose is achieved and that hepatotoxic doses are avoided, as well as that there is no extrahepatic deposition. MATERIAL AND METHODS: We use different amounts of yttrium-90 resin micro-spheres and a NEMA NU2-2007 phantom to check if the scanner maintains a response that allows real dosimetric calculations. RESULTS: The Gemini tomograph responds linearly in a wide range of activities with R2 = 0.9983. CONCLUSION: The detection capacity of the PET equipment allows us to carry out standard body studies with dosimetric purposes with times of five minutes per bed. It also make possible to verify the absence of extrahepatic deposition of significant amounts of yttrium 90 spheres.

[Heterotopic ossification in SARS-CoV-2: Scintigraphic and radiological images]. / Osificación heterotópica en paciente con SARS-CoV-2: imágenes gammagráficas y radiológicas.

Patients with severe COVID-19 can develop painful range-of-motion restrictions of large joints due to heterotopic ossification. We present the case of a patient who developed hip pain after prolonged admission for severe COVID-19 pneumonia. Conventional radiography, computed tomography and bone scan showed extensive heterotopic ossification in the hips. It is probable that both local and systemic factors contribute to the development of heterotopic ossifications and it is necessary to rule out this entity when these patients reported joint pain. Early diagnosis is important to provide non-pharmacological interventions such as mild passive mobilization and anti-inflammatory medication and in refractory cases surgical resection of the ectopic bone is consider.

Infiltración infrecuente de plexos coroideos en linfoma; importancia de la inclusión del cerebro en la adquisición de 18F-FDG PET / Uncommon choroid plexus infiltration in lymphoma: importance of adding the skull to the 18F-FDG PET acquisition

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Tumor miofibroblástico inflamatorio. Hallazgos en la PET/TC con 18F-FDG / Inflammatory myofibroblastic tumor.18F-FDG PET/CT findings

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Utility of low dose (18)F-FDG PET-CT in patients with suspected colorectal carcinoma recurrence in conventional diagnostic methods.

OBJECTIVE: To evaluate the efficacy of (18)F-FDG PET-CT in the diagnosis of recurrence of colorectal cancer (CRC) in patients with elevated values of carcinoembryonic antigen (CEA) and/or signs of recurrence in the multidetector CT (MDCT), and to demonstrate that good results can be obtained applying the ALARA principles. MATERIAL AND METHODS: A retrospective study of 54 patients with suspected CRC, who underwent an (18)F-FDG PET-CT, administering a mean dose of 222 MBq (6 mCi) of (18)F-FDG, from 07/2007 to 01/2011 was carried out. Seven patients were excluded, thus studying 47 (27 males, 20 females, mean age 63 years). Recurrence was confirmed by histopathology study in 14 cases and by clinical evolution in 33. The patients were divided into 4 groups. A: patients with elevation of CEA and suspected recurrence in the MDCT. B: elevation of CEA, without suspicious lesions in the MDCT. C: normal levels of CEA and positive MDCT. D: normal levels of CEA and uncertain MDCT. RESULTS: We found sensitivity, specificity, PPV, NPV and overall accuracy of 91%, 69%, 89%, 75% and 85% respectively. For group A, we found 100% sensitivity, in group B, 75% sensitivity with 100% specificity%, for C, sensitivity was 89% with 71% specificity. Finally, in group D, sensitivity was 100% and specificity 60%, respectively. CONCLUSION: Applying a low dose, the (18)F-FDG PET-CT has high diagnostic performance in patients with suspicion of CRC, approaching in a higher grade the ALARA criteria.