False Positive in [ 99m Tc]Tc-DPD Scintigraphy for Cardiac Amyloidosis Due to Intravenous Iron Administration.

ABSTRACT: [ 99m Tc]Tc-DPD (3,3-diphosphono-1,2-propanodicarboxylic acid) scintigraphy is an essential tool for diagnosing transthyretin amyloid cardiac amyloidosis. An 86-year-old woman suffering from heart failure with preserved ejection fraction underwent [ 99m Tc]Tc-DPD scintigraphy and a SPECT/CT for suspected transthyretin amyloid cardiac amyloidosis. The scan showed intracardiac and liver uptake. As the patient had taken intravenous iron on the morning of the scan, we decided to repeat the scan, but this time, it showed no uptake in the heart or the liver. Accordingly, we concluded the first result was a false positive due to drug interaction.

Gammagrafía hepatobiliar con SPECT/TC en el diagnóstico de una fístula biliopleural posquirúrgica / Hepatobiliary scintigraphy with SPECT/CT IN the diagnosis of postsurgical biliopleural fistula

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Partial PEGylation of superparamagnetic iron oxide nanoparticles thinly coated with amine-silane as a source of ultrastable tunable nanosystems for biomedical applications.

The development of superparamagnetic iron oxide nanoparticle (SPION)-based diagnostic and therapeutic nanosystems holds a promise of revolutionizing biomedicine, helping to solve important unmet clinical needs. Such potential will only be fulfilled if appropriate methods for SPION production and for their subsequent tailoring to specific applications are established, something that remains challenging. Here, we report a simple and low cost method to fabricate structurally and colloidally ultrastable, water soluble SPIONs. We used thermal decomposition to produce SPIONs of the highest quality, which were then thinly coated with an amine-silane derivative by ligand exchange, conferring hydrophilicity and great structural stability on the nanoparticles. Subsequent partial covalent occupancy of surface amine groups with polyethyleneglycol (PEG) was carried out to give them excellent colloidal stability, whilst still leaving reactive anchoring points for further functionalization. The correct composition and physicochemical properties of our PEGylated SPIONs and their precursors were confirmed using a broad range of analytical techniques, and we also demonstrated the biocompatible character of the resulting nanoparticles, as well as their suitability as T2 MRI contrast agents in vivo. Finally, using a near infra-red fluorophore, we also confirmed that these SPIONs are amenable to further tuning, to adapt them to a wide range of applications or to optimize their performance in particular settings. In summary, our work provides a novel and robust method for the production of SPIONs that can be used as a tunable platform for the development of smart diagnostic and therapeutic nanosystems.

Concordancia analítica de la tiroglobulina estimulada con tirotropina recombinante humana y tras privación hormonal previa a la terapia con 131I en pacientes con cáncer diferenciado de tiroides / Concordance between thyroglobulin determinations after diagnostic recombinant human TSH stimulation and after hormone withdrawal prior to131I therapy in patients with differentiated thyroid cancer

Objetivos: Comparar los resultados de tiroglobulina obtenidos ante estimulación con tirotropina recombinante humana (rhTSH) con fines diagnósticos y tras privación hormonal previa a la terapia con 131I. Pacientes y método: Se evaluó a 31 pacientes en seguimiento por cáncer diferenciado de tiroides (CDT) a los que se indicó dosis terapéutica de 131I. Fueron sometidos de forma consecutiva a ambos protocolos de estimulación, y el tratamiento con radioyodo distó 1-2 meses del procedimiento diagnóstico con rhTSH. Se realizaron determinaciones analíticas de TSH, tiroglobulina (Tg) y anticuerpos anti-Tg por métodos inmunométricos. Resultados: Las medianas de Tg obtenidas tras rhTSH y privación fueron de 1,10 y 1,80 ng/ml, respectivamente. Analizados como positivos o negativos, dichos valores mostraron un índice kappa de concordancia de 0,633. Los casos discordantes mostraron una mayor elevación de Tg en estímulo con rhTSH (3 casos) y sólo en 1 caso se obtuvo un resultado negativo con estimulación con rhTSH que luego se positivizó en la dosis ablativa. Conclusiones: El estímulo con rhTSH consigue elevaciones diagnósticas de TSH en todos los casos aplicados. Los valores de Tg obtenidos con ambos estímulos muestran un grado de concordancia elevado (AU)

Objectives: To compare the results of thyroglobulin (Tg) determination after diagnostic recombinant human thyroid-stimulating hormone (rhTSH) stimulation and after hormone withdrawal prior to 131I therapy. Patients and method: Thirty-one patients followed-up for differentiated thyroid cancer were evaluated. In all patients 131I therapy was indicated. All patients underwent both stimulation methods, with an interval of 1-2 months between diagnostic rhTSH administration and radioiodine therapy. Laboratory determinations of TSH, Tg and Tg antibodies were carried out by immunometric methods. Results: Median Tg values obtained after rhTSH stimulation and hormone withdrawal were 1.10 and 1.80 ng/ml, respectively. Considered as positive or negative, these values showed a kappa value of 0.633. Discordant cases showed greater elevation after rhTSH stimulation (3 patients). Only one patient showed a negative result after rhTSH stimulation, which was then positive after the ablative dose. Conclusions: Stimulus with rhTSH achieved diagnostic elevations of TSH in all patients. Tg levels after both stimulation methods showed a high degree of agreement (AU)