Description of the methodology for dosimetric quantification in treatments with 177Lu-DOTATATE. / Descripción de la metodología para la cuantificación dosimétrica en tratamientos con 177Lu-DOTATATE.

Implementation of dosimetry calculations in the daily practice of Nuclear Medicine Departments is, at this time, a controversial issue, partly due to the lack of a standardized methodology that is accepted by all interested parties (patients, nuclear medicine physicians and medical physicists). However, since the publication of RD 601/2019 there is a legal obligation to implement it, despite the fact that it is a complex and high resource consumption procedure. The aim of this article is to review the theoretical bases of in vivo dosimetry in treatments with 177Lu-DOTATATE. The exposed methodology is the one proposed by the MIRD Committee (Medical Internal Radiation Dose) of the SNMMI (Society of Nuclear Medicine & Molecular Imaging). According to this method, the absorbed dose is obtained as the product of 2factors: the time-integrated activity of the radiopharmaceutical present in a source region and a geometrical factor S. This approach, which a priori seems simple, in practice requires several SPECT/CT acquisitions, several measurements of the whole body activity and taking several blood samples, as well as hours of image processing and computation. The systematic implementation of these calculations, in all the patients we treat, will allow us to obtain homogeneous data to correlate the absorbed doses in the lesions with the biological effect of the treatment. The final purpose of the dosimetry calculations is to be able to maximize the therapeutic effect in the lesions, controlling the radiotoxicity in the organs at risk.

PET/CT with 18F-Fluordesoxyglucose in patients with suspected endovascular prosthesis infection. / PET/TC con 18F-Fluordesoxiglucosa en pacientes con sospecha de infección de prótesis endovasculares.

OBJECTIVE: Infection of large vessel prostheses is a rare but critical complication. The aim of this work is to assess the impact of PET/CT with 18F-Fluordesoxyglucose (PET-FDG) on the diagnosis of infection in our environment. MATERIAL AND METHODS: Thirty-five patients (38 scans) were evaluated for suspected prosthetic infection. A qualitative analysis was performed taking into account the distribution of the radiopharmaceutical, categorizing the studies as positive or negative for infection. Those with focal or multifocal deposits along the vascular prosthesis were considered positive, and negative if a homogeneous and diffuse distribution over the whole prosthesis was observed, or a total absence of uptake. A semi-quantitative analysis was performed using SUVmax and average SUV values, and a metabolic index was calculated (SUVmax of the graft / average SUV of the normal vascular pool). RESULTS: The PET-FDG study was positive in 20 patients, with a diagnostic accuracy of 84%. The 38 PET-FDG scans performed showed positive capture patterns (focal in 6, multifocal in 15, diffuse in 4) and negative pattern in the remaining 13. The sensitivity, specificity, positive and negative predictive values obtained for the PET-FDG were 95%, 89%, 90% and 94%, and for the AngioTC study 50%, 73%, 73% and 50%, respectively. The area values under the ROC curve were as follows: for the AngioTC 0.642 (not significant), and for the SUVmax values of 0.925 (p<0.005), average SUV of 0.922 (p<0.005) and for the metabolic index of 0.917 (p<0.005). CONCLUSIONS: The PET-FDG proves to be a tool with high diagnostic accuracy in the infection of vascular prosthesis, both visual analysis according to patterns and semi-quantitative.

[Bone scintigraphy with 99mTc-MDP in a patient with acute lymphoblastic leukemia initially diagnosed of Still's disease]. / Gammagrafía ósea con 99mTc-MDP en un paciente con leucemia aguda linfoblástica diagnosticado inicialmente de enfermedad de Still.

We present a 43-year-old male, who was admitted with the diagnosis of Adult-onset Still's disease, after several months of arthralgias, febricula and loss of weight. Chest x-ray, abdominal ultrasonography, chest, abdomen and pelvic CT scan and bone scintigraphy were performed. Scintigraphic findings oriented to the performance of a bone marrow biopsy with diagnosis of acute lymphoblastic leukemia.

Gammagrafía ósea con 99mTc-MDP en un paciente con leucemia aguda linfoblástica diagnosticado inicialmente de enfermedad de Still / Bone scintigraphy with 99mTc-MDP in a patient with acute lymphoblastic leukemia initially diagnosed of Still’s disease

Presentamos el caso de un varón de 43 años, que ingresa con el diagnóstico de enfermedad de Still, tras varios meses aquejado de artralgias, febrícula y pérdida de peso. Se realizan radiografía de tórax, ecografía abdominal, TC de tórax, abdomen y pelvis con contraste y gammagrafía ósea. Los hallazgos gammagráficos orientan hacia la realización de punción de médula ósea con el diagnóstico de leucemia linfoblástica aguda

We present a 43-year-old male, who was admitted with the diagnosis of Adult-onset Still's disease, after several months of arthralgias, febricula and loss of weight. Chest x-ray, abdominal ultrasonography, chest, abdomen and pelvic CT scan and bone scintigraphy were performed. Scintigraphic findings oriented to the performance of a bone marrow biopsy with diagnosis of acute lymphoblastic leukemia

Estructura cognitiva de los médicos de familia en formación sobre la relación médico-paciente / The thought structure of family doctors in training concerning the doctor-patient relationship

Objetivos. Conocer y comparar la estructura cognitiva de los residentes de MFyC sobre la relación médico-paciente. Diseño. Descriptivo, cualitativo. Emplazamiento. Atención primaria. Participantes. Diez residentes de primer año seleccionados por muestreo intencional. Mediciones. Entrevista de Piaget modificada por Pinies, evaluada con la técnica del análisis proposicional de conceptos y mapas conceptuales. Se definen 5 áreas temáticas sobre la relación médico-paciente: importancia y repercusiones, características y requisitos, modelo de relación, comportamiento del paciente y comportamiento del médico. Resultados. Los conceptos no están suficientemente elaborados. La importancia de la relación médicopaciente es reconocida, pero no todas sus repercusiones. El requisito deseable de ésta más citado es la confianza del paciente. Los entrevistados apuestan por una relación en la que el paciente es pasivo aunque son conscientes del peligro del interrogatorio dirigido. La personalidad del paciente es el determinante de su comportamiento más citado, pero se comentan otros como creencias y expectativas. La decisión de consultar no se ve solamente como producto de los síntomas. Entre los mecanismos de defensa la negación es el más reconocido. Se señala el papel de los sentimientos del médico pero no cómo neutralizarlos; tampoco se resalta la formación. Conclusiones. Existe una insuficiente apreciación de la importancia práctica de la relación médicopaciente. Es mayoritario un modelo de relación directiva y sin una orientación biopsicosocial. La formación en esta área es prioritaria, aunque su necesidad no sea percibida. Se debe investigar qué tipos de conocimientos refleja la estructura cognitiva y su papel en el comportamiento del profesional (AU)