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.

[Thymic uptake of 18FFDG following radioiodine ablation therapy]. / Captación de 18F-FDG en timo tras terapia ablativa de restos tiroideos con 131I.

We report the case of a 47 year-old woman with a history of non-Hodgkin's lymphoma. During the course of her disease, we performed various (18F)FDG PET/CT that identified several significant incidental findings. First, we incidentally identified a hypermetabolic nodule in the left thyroid lobe, whose final diagnosis was differentiated thyroid carcinoma. Second, metabolic activity was visualized in the thymus secondary to ablative treatment with radioiodine. This uptake disappeared in subsequent studies. Several papers have reported thymic rebound following chemotherapy but we have found only one case report of (18F)FDG uptake after radioiodine treatment. On the other hand, this case is of interest because it supports the benefit of studying the hypermetabolic thyroid nodules incidentally detected on the PET/CT performed for other reasons.

[Utility of diuretic renography in the detection of an enteroureteral fistula]. / Utilidad del renograma diurético en la detección de una fístula enteroureteral.

After a 2-year-old male with left impairment underwent surgery for a left vesicoureteral stenosis, his renal function was followed up by means of dynamic renal scintigraphy with 99mTc-DTPA. Incidental radiotracer accumulation was observed in left hemiabdomen tracing the descending and sigmoid colon. A vesico-colonic fistula was suspected. However, ultrasonography and cystography studies showed no presence of a vesico-enteric fistula. Because the patient persisted without symptoms, an expectant approach was adopted. One year later, he began to suffer watery diarrhoea episodes. 99mTc-DTPA renography was again performed to re-evaluated renal function and explore presence of urinary-enteric fistula. Diuretic renography demonstrated the presence of a vesical leak to sigmoid gut, which was confirmed by recovery of fecal matter from the patient. Both isotopic renograms evidenced the presence of uretero-sigmoid fistula, an uncommon postsurgical that was not detected by cystography, ultrasonography or RMN. The patient subsequently underwent surgery for fistula repair.