Tratamiento con 177LU-DOTATATE en tumores neuroendocrinos. Estudio preliminar / 177Lu-DOTATATE treatment in neuroendocrine tumours. A preliminary study

La terapia con péptidos análogos de la somatostatina marcados con radionúclidos es un nuevo tratamiento prometedor para tratar tumores neuroendocrinos. El objetivo del presente estudio preliminar es presentar nuestra experiencia en la terapia con 177Lu-DOTATATE y evaluar la tolerabilidad y la eficacia a corto plazo en pacientes con tumores que expresan receptores para la somatostatina. Se han tratado 7 pacientes con tumores neuroendocrinos metastásicos, cada uno con 4 dosis de 177Lu-DOTATATE y se ha evaluado su respuesta al tratamiento en forma de respuesta bioquímica (marcadores tumorales y analítica), según métodos de imagen (gammagrafía de receptores de somatostatina, tomografía computarizada y resonancia magnética) y respuesta funcional y de calidad de vida (mediante la Escala de actividad de Karnofsky). Se ha evaluado también la toxicidad del tratamiento. Los resultados obtenidos han sido los siguientes: respuesta bioquímica: el 60% de los pacientes mostraron una normalización de sus niveles de marcadores tumorales, mientras que en el 40% disminuyeron de manera significativa; respuesta en técnicas de imagen: el 85,7% presentaron una respuesta parcial, mientras que el 14,3% mostraron enfermedad estable; mejoría de la calidad de vida: el 100% de los pacientes mostraron una mejoría significativa en la calidad de vida con un incremento de la Escala de actividad de Karnofsky, y en cuanto a la toxicidad: ningún paciente presentó toxicidad aguda o crónica, y el 42,8% de los pacientes presentaron toxicidad subaguda hematológica transitoria. A pesar de tratarse de un estudio preliminar podemos afirmar que el tratamiento con 177Lu-DOTATATE es un tratamiento seguro, con pocos efectos adversos y que consigue una respuesta objetiva en la mayoría de los pacientes (AU)

Therapy with radiolabelled somatostatin analogue peptides is a promising new therapy to treat neuroendocrine tumours. The aim of this preliminary study is to present our experience with 177Lu-DOTATATE therapy, and evaluate tolerability and short-term efficacy in patients with tumours expressing somatostatin receptors. A total of 7 patients with metastatic neuroendocrine tumours were treated, each with 4 doses of 177Lu-DOTATATE. The treatment response was evaluated in the form of biochemical response (tumour markers), imaging methods (somatostatin receptor scintigraphy, computed tomography, and magnetic resonance), and functional and quality of life responses using the Karnofsky performance status scale. Treatment toxicity was also evaluated. The results obtained were as follows: Biochemical response: 60% of patients showed tumour marker levels returning to normal, while they decreased significantly in the remaining 40%. Imaging response: 85.7% had a partial response, while 14.3% showed stable disease. All (100%) patients showed a significant improvement in quality of life, with increased Karnofsky scale scores. No patient had acute or chronic toxicity, and subacute transient haematological toxicity was observed in 42.8% of patients. Despite being a preliminary study, it was found that treatment with 177Lu-DOTATATE is a safe treatment with few side effects, and an objective response was achieved in most patients (AU)

Evaluation of PET texture features with heterogeneous phantoms: complementarity and effect of motion and segmentation method.

A major source of error in quantitative PET/CT scans of lung cancer tumors is respiratory motion. Regarding the variability of PET texture features (TF), the impact of respiratory motion has not been properly studied with experimental phantoms. The primary aim of this work was to evaluate the current use of PET texture analysis for heterogeneity characterization in lesions affected by respiratory motion. Twenty-eight heterogeneous lesions were simulated by a mixture of alginate and 18 F-fluoro-2-deoxy-D-glucose (FDG). Sixteen respiratory patterns were applied. Firstly, the TF response for different heterogeneous phantoms and its robustness with respect to the segmentation method were calculated. Secondly, the variability for TF derived from PET image with (gated, G-) and without (ungated, U-) motion compensation was analyzed. Finally, TF complementarity was assessed. In the comparison of TF derived from the ideal contour with respect to TF derived from 40%-threshold and adaptive-threshold PET contours, 7/8 TF showed strong linear correlation (LC) (p < 0.001, r > 0.75), despite a significant volume underestimation. Independence of lesion movement (LC in 100% of the combined pairs of movements, p < 0.05) was obtained for 1/8 TF with U-image (width of the volume-activity histogram, WH) and 4/8 TF with G-image (WH and energy (ENG), local-homogeneity (LH) and entropy (ENT), derived from the co-ocurrence matrix). Their variability in terms of the coefficient of variance ([Formula: see text]) resulted in [Formula: see text](WH) = 0.18 on the U-image and [Formula: see text](WH) = 0.24, [Formula: see text](ENG) = 0.15, [Formula: see text](LH) = 0.07 and [Formula: see text](ENT) = 0.06 on the G-image. Apart from WH (r > 0.9, p < 0.001), not one of these TF has shown LC with C max. Complementarity was observed for the TF pairs: ENG-LH, CONT (contrast)-ENT and LH-ENT. In conclusion, the effect of respiratory motion should be taken into account when the heterogeneity of lung cancer is quantified on PET/CT images. Despite inaccurate volume delineation, TF derived from 40% and COA contours could be reliable for their prognostic use. The TF that exhibited simultaneous added value and independence of lesion movement were ENG and ENT computed from the G-image. Their use is therefore recommended for heterogeneity quantification of lesions affected by respiratory motion.

177Lu-DOTATATE treatment in neuroendocrine tumours. A preliminary study. / Tratamiento con 177LU-DOTATATE en tumores neuroendocrinos. Estudio preliminar.

Therapy with radiolabelled somatostatin analogue peptides is a promising new therapy to treat neuroendocrine tumours. The aim of this preliminary study is to present our experience with 177Lu-DOTATATE therapy, and evaluate tolerability and short-term efficacy in patients with tumours expressing somatostatin receptors. A total of 7 patients with metastatic neuroendocrine tumours were treated, each with 4 doses of 177Lu-DOTATATE. The treatment response was evaluated in the form of biochemical response (tumour markers), imaging methods (somatostatin receptor scintigraphy, computed tomography, and magnetic resonance), and functional and quality of life responses using the Karnofsky performance status scale. Treatment toxicity was also evaluated. The results obtained were as follows: Biochemical response: 60% of patients showed tumour marker levels returning to normal, while they decreased significantly in the remaining 40%. Imaging response: 85.7% had a partial response, while 14.3% showed stable disease. All (100%) patients showed a significant improvement in quality of life, with increased Karnofsky scale scores. No patient had acute or chronic toxicity, and subacute transient haematological toxicity was observed in 42.8% of patients. Despite being a preliminary study, it was found that treatment with 177Lu-DOTATATE is a safe treatment with few side effects, and an objective response was achieved in most patients.

El rastreo oseo isotópico en la fibromialgia reumática / Oseo fibromyalgia syndrome

Existen muy pocos estudios que relacionen la Fibromialgia reumática (FR) con el Rastreo Óseo Isotópico (RO). El objetivo de este trabajo es evaluar el valor del RO en el diagnóstico de la FR e intentar encontrar un patrón óseo gammagráfico que permita el diagnóstico de esta patología, al igual que sucede con otras enfermedades osteoarticulares reumáticas, ayudando también así en el diagnóstico diferencial con éstas. Se han estudiado 19 mujeres (edad 24-69 años). 14 de ellas presentaban diagnóstico clínico de FR y 5 sospecha clínica. A todas ellas se les realizó un gran número de pruebas diagnósticas: analíticas sanguíneas, Radiología convencional, Electrocardiogramas, Electroencefalogramas, Electromiografia, Ecografía, Tomografía computerizada, Resonancia magnética y RO. En todos los RO se observaron incrementos anormales de captación de intensidad variable, de localización difusa o puntual y a nivel poliarticular, además de los hallazgos ya conocidos por la patología osteoarticular concomitante de las pacientes. No se observó la presencia de fase vascular positiva en ningún caso a pesar de ser zonas dolorosas en la exploración clínica. No se observó relación entre la localización e intensidad de captación del radiofármaco y la presencia clínica de dolor.Pensamos que los pacientes con FR podrían presentar un patrón gammagráfico variable en cuanto a localización e intensidad de captación, de tipo poliarticular en fase tardía.