El método Pilates es eficaz en el tratamiento para el abordaje terapéutico del dolor lumbar crónico. Una revisión sistemática / The Pilates method is effective in the treatment for the therapeutic approach of the chronic low back pain. A systematic review / O método Pilates é eficaz no tratamento para a abordagem terapêutica da dor lombar crônica. Uma revisão sistemática

OBJETIVOS: Revisar la literatura más actual para comprobar la efectividad del método Pilates en el dolor lumbar crónico respecto a su efectividad, duración y dosimetría. MÉTODOS: Se realiza una búsqueda bibliográfica de ensayos clínicos publicados en los últimos cinco años en las bases de datos de Medline, Scopus y PEDro. De 257 estudios hallados, diez son seleccionados atendiendo a los criterios de inclusión y exclusión, siendo posteriormente evaluados en base a la calidad metodológica mediante la escala PEDro. RESULTADOS: El método Pilates reduce la sintomatología asociada al dolor lumbar crónico a corto plazo, no siendo superior a otros programas activos. Su aplicación en máquinas parece ser más efectiva. Actualmente, no existe consenso respecto a su dosimetría y su efectividad a largo plazo. CONCLUSIONES: El método Pilates puede ser efectivo a corto plazo para el abordaje terapéutico del dolor lumbar crónico, sin embargo, no ha demostrado ser superior a otros programas de ejercicios activos

OBJECTIVES: To review the most current literature to verify the effectiveness of the Pilates method for the approach of the chronic low back pain regarding to its effectiveness, its duration and its dosimetry. METHODS: A bibliography search of clinical trials published in the last five years was carried out using the databases of Medline, Scopus and PEDro. Of the 257 studies found, ten were selected according to the inclusion and exclusion criteria, and then assessed based on the methodological quality through the PEDro scale. RESULTS: The Pilates method reduces the symptoms associated with the chronic low back pain in the short term, it is not better than other active programs. Its application in machines seems to be more effective. Currently, there is no consensus regarding to its dosimetry and its effectiveness in the long term. CONCLUSIONS: The Pilates method can be effective in the short term for the therapeutic approach of the chronic low back pain. In contrast, the effectiveness of the Pilates method has not shown to be better than other active exercise programs

OBJETIVOS: Revisar a literatura mais atual para verificar a eficácia do método Pilates na dor lombar crônica quanto à sua eficácia, duração e dosimetria. MÉTODOS: É realizada uma pesquisa bibliográfica de ensaios clínicos publicados nos últimos cinco anos nas bases de dados Medline, Scopus e PEDro. Dos 257 estudos encontrados, dez foram selecionados com base nos critérios de inclusão e exclusão, sendo posteriormente avaliados com base na qualidade metodológica por meio da escala PEDro. RESULTADOS: O método Pilates reduz os sintomas associados à lombalgia crônica em curto prazo, não sendo superior a outros programas ativos. Sua aplicação em máquinas parece ser mais eficaz. Atualmente, não há consenso sobre sua dosimetria e sua eficácia em longo prazo. CONCLUSÕES: O método Pilates pode ser eficaz em curto prazo na abordagem terapêutica da lombalgia crônica, porém, não se mostrou superior a outros programas de exercícios ativos

Estudio prospectivo comparativo de dos métodos de cálculo individual de la actividad de 131I en el tratamiento del hipertiroidismo / A prospective comparative study of two methods of individual calculation of 131I activity in the treatment of hyperthyroidism

OBJETIVO: El radioyodo (131I) constituye una modalidad establecida de tratamiento definitivo del hipertiroidismo. A pesar de la vasta experiencia existente, persisten varios aspectos por clarificar, como qué tipo de dosis emplear, ¿fijas o calculadas? El objetivo del estudio fue determinar si se podría mejorar la eficacia de este tratamiento implementando un método simple de cálculo dosimétrico que incluyera la estimación ecográfica del volumen tiroideo y una medida única de captación de 131I (24h). MÉTODOS: Diseñamos un estudio prospectivo de no inferioridad comparando entre dos modalidades de cálculo de la actividad de radioyodo: el método de dosis «semifijas» (A) y el de dosis «calculadas» (B). El primero consistió en escaladas de actividad (peldaños de 185MBq) teniendo en cuenta: etiología del hipertiroidismo, captación de 131I y objetivo terapéutico. El segundo se basó en el concepto de «compromiso dosimétrico», considerando como únicos factores la captación y el volumen tiroideos, empleando una vida media estándar de 5,5días. La dosis absorbida diana fue 150Gy, aunque tras un análisis preliminar (100 primeros casos) se aumentó a 200Gy en los bocios difusos tóxicos (BDT). RESULTADOS: Se incluyeron 212 pacientes. El métodoB resultó al menos igual de eficaz en cuanto al resultado final y funcional, con tendencia a más éxitos y menos hipotiroidismo. Además, las actividades administradas fueron significativamente menores. CONCLUSIÓN: En la terapia con radioyodo del hipertiroidismo se pudo implementar un método dosimétrico sencillo que proporcionó resultados al menos iguales a los de un método basado en dosis fijas, con actividades administradas inferiores

OBJECTIVE: Radioiodine (131I) is an established modality of definitive treatment of hyperthyroidism. In spite of the vast experience available, there are still several aspects to be clarified, such as whether fixed or calculated doses should be used. The aim of this study was to assess whether efficacy of this treatment could be improved by implementing a simple dosimetric calculation method including ultrasonographic estimation of thyroid volume and a single measurement of 24-hour 131I thyroid uptake. METHODS: A prospective non-inferiority study was designed to compare two procedures to calculate radioiodine activity: the «semi-fixed» dose method (A), and the «calculated» dose method (B). The first consisted of activity escalation (185MBq steps) based on etiology of hyperthyroidism, 131I uptake, and treatment objective. The second method was based on the «dosimetric compromise» concept, considering 24-hour uptake and thyroid volume as the only factors and using a standard half-life of 5.5 days. The target absorbed dose was 150Gy, but after a preliminary analysis (first 100 cases) it was increased to 200Gy in diffuse toxic goiters (DTGs). RESULTS: A total of 212 patients were included. MethodB was at least as effective in terms of final and functional outcome, with a trend to more success and less hypothyroidism. In addition, activities administered were significantly lower. CONCLUSION: In radioiodine therapy of hyperthyroidism, a simple dosimetric method that provided results at least equal to those of a fixed dose-based method, with lower administered activities, could be implemented

Dosimetría en medicina nuclear terapéutica: ¿podemos hacerlo mejor? / Dosimetry in therapeutic nuclear medicine: can we do it better?

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Estado actual de la protección radiológica en procedimientos endourológicos en España / Current status of radiological protection in endourological procedures in Spain

Objetivo: Conocer el grado de formación en protección radiológica (PR) de los urólogos españoles que realizan técnicas endourológicas, así como analizar el empleo de medidas de control y protección frente a radiaciones ionizantes. Material y métodos: Encuesta realizada mediante la Plataforma de Investigación de Estudios Multicéntricos (PIEM) a los 1.894 asociados de la Asociación Española de Urología, entre abril y octubre de 2015. El cuestionario comprende 21 preguntas que interrogan sobre la actividad endourológica realizada, la formación en PR y el empleo de medidas protectoras y de dosimetría personal. Se obtuvo un 17% de respondedores, siendo finalmente válidas para análisis 238 encuestas. Resultados: El 63% de los encuestados no tenían ningún tipo de formación en PR, el 25% poseían acreditación de primer nivel y únicamente un 12% de segundo nivel. El empleo de dosimetría de solapa, muñeca y cristalino era realizada por un 57, 27 y 2% de los urólogos, respectivamente. El uso de medidas de protección frente a radiaciones resultó ser insuficiente. El 53% de los urólogos con mayor riesgo de exposición no tenían ninguna formación en PR, un 30% no usaban dosímetro de solapa y un 40% no empleaban ni delantal ni collar tiroideo durante los procedimientos endourológicos. Conclusiones: La formación en PR, el control de dosis y el empleo de medidas de protección frente a radiaciones ionizantes es insuficiente, incluso en aquellos profesionales más expuestos a radiaciones. Es fundamental corregir estas graves deficiencias en PR tanto a nivel individual como de servicios de urología, sociedades científicas y autoridades sanitarias

Objective: To discover the extent of training in radiological protection (RP) of Spanish urologists who perform endourological procedures, and to analyse the use of on ionising radiation control and protection measures. Material and methods: A survey conducted through the Plataforma de Investigación de Estudios Multicéntricos (PIEM) (Multicentre Study Research Platform) on the 1,894 associates of the Spanish Association of Urology, between April and October 2015. The questionnaire comprised 21 questions on endourological activity undertaken, RP training, and the use of protective measures, and personal dosimetry. Seventeen percent responded, and 238 surveys were eventually validated for study. Results: Sixty-three percent of the respondents had received no type of RP training, 25% had first level accreditation, and only 12% second level. Fifty-seven percent, 27%, and 2% of the urologists used flap, wrist and crystalline dosimetry respectively. Use of radiation protection measures was insufficient. Fifty-three percent of the urologists at greatest risk of exposure had had no training in RP, 30% did not use flap dosimetry, and 40% used neither an apron or thyroid collar during the endourological procedures. Conclusions: RP training, dosis monitoring, and the use of ionising radiation protective measures are insufficient, even by practitioners most exposed to radiation. It is essential that these serious shortcomings in RP are corrected, at the level of the individual, in urology departments, scientific societies, and the health authorities

Magnitudes y unidades para dosimetría del personal ocupacionalmente expuesto en radiodiagnóstico e intervencionismo / Quantities and units for dosimetry of occupationally exposed personnel in diagnostic and interventional radiology

Resumen:Existen diversos documentos y recomendaciones internacionales sobre nombres, conceptos, definiciones y campos de aplicación para diversas magnitudes y unidades utilizadas para monitorear los niveles de radiación ionizante a los que son expuestos los trabajadores durante los procedimientos de Radiodiagnóstico e Intervencionismo. Sin embargo, la legislación nacional, al igual que para la dosimetría de los pacientes, no se encuentra actualizada en este sentido y no contempla en sus documentos un glosario actualizado que permita encontrar en forma rápida y precisa este tipo de información. Por lo anterior, este trabajo de revisión corresponde a un segundo documento guía, complementario a nuestro trabajo publicado en 2015 titulado "Magnitudes y unidades para dosimetría a pacientes en radiodiagnóstico e intervencionismo", que describe de manera didáctica y en un lenguaje sencillo para los profesionales de la salud y áreas afines, las principales magnitudes y unidades que se deben conocer y utilizar en la dosimetría ocupacional de los trabajadores que participan en procedimientos de Radiodiagnóstico e Intervencionismo.

Abstract: There are many documents and international recommendations offer names, concepts, definitions and fields of application for various quantities and units used to monitor the exposure levels of ionising radiation to which workers are exposed during the diagnostic and interventional radiology procedures. However, as in the case of patient dosimetry, national legislation is not up-to-date in this area and nowhere does it establish an up-to-date glossary that would facilitate rapid and precise location of this kind of information. In light of the foregoing, this review paper presents a second guidance document, complementary to our published article in 2015 titled "Quantities and units used in patient dosimetry in radiodiagnostic and intervencional procedures", which describes the principal quantities and units that must be known and used in occupational dosimetry for workers participating in diagnostic and interventional radiology procedures, in a didactical manner and using simple language for professionals in health and similar areas.

PET/TAC: bases físicas, instrumentación y avances / PET/CT: underlying physics, instrumentation, and advances

Desde su introducción, el objetivo principal de un PET/TAC fue proporcionar estudios de alta calidad clínica tanto de PET como de TAC, y presentarlos a los médicos nucleares y radiólogos como una imagen fusionada y perfectamente alineada. El uso de las imágenes de PET y TAC fusionadas se convirtió en muy poco tiempo en rutina clínica, lo que demuestra el gran potencial que tienen estos equipos híbridos. Gracias a este éxito, los fabricantes se han centrado en diseñar sistemas PET y TAC de alto rendimiento y prestaciones, en lugar de ver al TAC en una función más reducida como la de mero corrector de la atenuación para PET. Desde el primer sistema PET/TAC comercial en 2001, tanto la componente PET como la TAC han mejorado enormemente. En el caso del PET, cristales centelleadores más rápidos y con alto poder de frenado como el LYSO han posibilitado la construcción de dispositivos con una mayor sensibilidad, con reducción en el número de coincidencias no deseadas y el uso de la técnica de tiempo de vuelo (TOF, Time of Flight). Todos estos avances llevan a un aumento de la detección de lesiones, especialmente en situaciones con fondo muy ruidoso. Los métodos de reconstrucción iterativos junto con las correcciones implementadas durante la reconstrucción y el uso de la función de dispersión de punto han proporcionado mejoras en la calidad de la imagen. Paralelamente, se han producido mejoras significativas en la instrumentación del TAC, y se puede considerar que los TAC de 64 y 128 filas de detectores han sido incorporados a los PET/TAC actuales. Con ello se pueden obtener imágenes anatómicas de alta calidad diagnóstica en unos pocos segundos y estas se usan tanto para la corrección de atenuación del PET como para proporcionar información diagnóstica. Además, en la actualidad casi todos los escáneres PET/TAC cuentan con su sistema de modulación de la dosis en función de la región escaneada que se imparte al paciente por estudio de TAC. En este artículo se revisarán las bases físicas del PET y del TAC por separado, se describirán las modificaciones realizadas en la instrumentación y los protocolos estándar de un sistema conjunto PET/TAC y se finalizará destacando los avances más importantes de este sistema híbrido (AU)

Since it was first introduced, the main goal of PET/CT has been to provide both PET and CT images with high clinical quality and to present them to radiologists and specialists in nuclear medicine as a fused, perfectly aligned image. The use of fused PET and CT images quickly became routine in clinical practice, showing the great potential of these hybrid scanners. Thanks to this success, manufacturers have gone beyond considering CT as a mere attenuation corrector for PET, concentrating instead on design high performance PET and CT scanners with more interesting features. Since the first commercial PET/CT scanner became available in 2001, both the PET component and the CT component have improved immensely. In the case of PET, faster scintillation crystals with high stopping power such as LYSO crystals have enabled more sensitive devices to be built, making it possible to reduce the number of undesired coincidence events and to use time of flight (TOF) techniques. All these advances have improved lesion detection, especially in situations with very noisy backgrounds. Iterative reconstruction methods, together with the corrections carried out during the reconstruction and the use of the point-spread function, have improved image quality. In parallel, CT instrumentation has also improved significantly, and 64- and 128-row detectors have been incorporated into the most modern PET/CT scanners. This makes it possible to obtain high quality diagnostic anatomic images in a few seconds that both enable the correction of PET attenuation and provide information for diagnosis. Furthermore, nowadays nearly all PET/CT scanners have a system that modulates the dose of radiation that the patient is exposed to in the CT study in function of the region scanned. This article reviews the underlying physics of PET and CT imaging separately, describes the changes in the instrumentation and standard protocols in a combined PET/CT system, and finally points out the most important advances in this hybrid imaging modality (AU)

Dosimetric predictors of acute hematologic toxicity during concurrent intensity-modulated radiotherapy and chemotherapy for anal cancer

Purpose. This study aimed at investigating whether the irradiated volume of pelvic bone marrow (PBM) and specific subsites may predict the occurrence of acute hematologic toxicity (HT) in anal cancer patients undergoing concurrent chemo-radiation. Methods. 50 patients, submitted to IMRT and concurrent chemotherapy, were analyzed. Several bony structures were defined on planning-CT: PBM and lumbar-sacral (LSBM), lower pelvis (LPBM) and iliac (IBM) bone marrow. On dose-volume histograms, dosimetric parameters were taken. Endpoints included white blood-cell-count (WBC), absolute-neutrophil-count (ANC), hemoglobin (Hb) and platelet nadirs and acute hematologic toxicity (HT) according to RTOG scoring scale. Generalized linear modeling was used to find correlations between dosimetric variables and blood cell nadirs, while logistic regression analysis was used to test correlation with ≥G3 HT. Receiver Operating Characteristic (ROC) curve analysis was used to evaluate the optimal cut-off points for predictive dosimetric variables with the Youden method. Results. Maximum detected acute HT comprised 38 % of ≥G3 leukopenia and 32 % of ≥G3 neutropenia. Grade 2 anemia was observed in 4 % of patients and ≥G3 thrombocytopenia in 10 %. On multivariate analysis a higher PBM-V20 was associated with lower WBC nadir. Increased LSBM-V40 was correlated with a higher likelihood to develop ≥G3 HT. A cut-off point at 41 % for LSBM-V40 was found. Patients with LSBM-V40 ≥41 % were more likely to develop ≥G3 HT (55.3 vs. 32.4 %; p < 0.01). Conclusions. Increased low-dose to pelvic bony structures significantly predicted for WBC decrease. Medium-high dose to specific osseous subsites was associated with a higher probability of HT. LSBM-V40 was a strong predictor of ≥G3 HT. A threshold at 41 % for LSBM-V40 could be used to limit HT (AU)

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Análisis monoinstitucional del impacto en control local de la braquiterapia intersticial de alta tasa en fracción única de 7 Gy / A single-institution analysis of the effect on local control of high-dose rate brachytherapy boost in a single 7 Gy fraction

Objetivo. Evaluar el impacto de la sobreimpresión con fracción única de braquiterapia de alta tasa en estadios iniciales del cáncer de mama en términos de control local, supervivencia global y toxicidad. Pacientes y métodos. Tras un tratamiento conservador, 137 pacientes, con una edad media de 57 años, recibieron sobreimpresión con braquiterapia de alta tasa en fracción única de 7 Gy entre enero de 2002 y diciembre de 2012. Recibieron quimioterapia el 70% y hormonoterapia el 67%. Resultados. Con un seguimiento medio de casi 8 años, la supervivencia global a los 5 y 10 años fue de 89,5 y 87,7%, respectivamente, con una supervivencia libre de recaída local a los 5 años del 99,3%. Los factores favorecedores de recaída local fueron el tamaño tumoral, la presencia de carcinoma in situ, un margen próximo y un grado iii. La toxicidad aguda fue poco frecuente y de rápida resolución. La fibrosis moderada fue el efecto secundario tardío predominante. Conclusiones. La sobreimpresión con braquiterapia intersticial en fracción única de 7 Gy en estadios iniciales del cáncer de mama es una técnica bien tolerada, con toxicidades tardías aceptables, que permite un excelente control local tumoral acortando el tiempo de tratamiento (AU)

Objective. To evaluate the impact of single fraction boost high-dose rate brachytherapy for breast cancer in early stages in terms of local control, overall survival and toxicity. Patients and methods. After conservative treatment 137 patients, mean age was 57 years, received high-dose rate brachytherapy boost in only fraction of 7 Gy between January 2002 and December 2012. Chemotherapy was used in 70% of the patients and hormone treatment in 67%. Results. At a mean follow-up 90 months, at 5 and 10 years the overall survival was 89.5 and 87.7%, respectively, and local recurrence free survival was 99.3% at 5 years. The risk factors for local recurrence were tumor size, carcinoma in situ, involved margins and grade iii. Acute toxicity was rare and rapid resolution. Moderate fibrosis was the most common late effect. Conclusions. High-dose rate brachytherapy boost in only fraction of 7 Gy to the tumour bed in early stage breast cancer is well tolerated with long term aceptable toxicities and improved local tumor control with a short duration of treatment (AU)

The effect of slice thickness on target and organs at risk volumes, dosimetric coverage and radiobiological impact in IMRT planning

Purpose: Dose-volume histogram (DVH) has become an important tool for evaluation of radiation outcome as reflected from many clinical protocols. While dosimetric accuracy in treatment planning system (TPS) is well quantified, the variability in volume estimation is uncertain due to reconstruction algorithm that is investigated in this study. In addition, the impact of dose distribution and tumor control probability (TCP) were also investigated with CT slice thickness for IMRT planning. Materials and methods: A water phantom containing various objects with accurately known volume ranging from 1 to 100 cm3 was scanned with 1, 2, 3, 5, and 10 mm slice thickness. The CT data sets were sent to Eclipse TPS for contour delineation and volume estimation. The data were compared with known volume for the estimation of error in the volume of each structure. IMRT Plans were generated on phantom containing four objects with different slice thickness (1–5 mm) to calculate TCP. ICRU-83- recommended dose points such as D2%, D50%, D98%, as well as homogeneity and conformity index were also calculated. Results: The variability of volumes with CT slice thickness was significant especially for small volume structures. A maximum error of 92 % was noticed for 1 cm3 volume of object with 10 mm slice thickness, whereas it was *19 % for 1 mm slice thickness. For 2 and 3 cm3 objects, the maximum error of 99 % was noticed with 10 mm slice thickness and *60 % with 5 mm. The differences are smaller for larger volumes with a cutoff at about 20 cm3. The calculated volume of the objects is a function of reconstruction algorithm and slice thickness. The PTV mean dose and TCP decreased with increasing slice thickness. Maximum variation of *5 % was noticed in mean dose and *2 % in TCP with change in slice thickness from 1 to 5 mm. The relative decrease in target volume receiving 95 % of the prescribed dose is *5 % with change in slice thickness from 1 to 5 mm. The homogeneity index increases up to 163 % and conformity index decreases by 4 % between 1 and 5 mm slice thickness, producing highly inhomogeneous and least conformal treatment plan. Conclusions: Estimation of a volume is dependent on CT slice thickness and the contouring algorithm in a TPS. During commissioning of TPS and for all clinical protocols, evaluation of volume should be included to provide the limit of accuracy in DVH from TPS, especially for small objects. A smaller slice thickness provides superior dosimetry with improved TCP. Thus, the smallest possible slice thickness should be used for IMRT planning, especially when smaller structures are present (AU)

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Dosimetría individualizada para pacientes de cáncer diferenciado de tiroides basada en tasa de dosis externa. Optimización del número de medidas / Individualised dosimetry in patients with differentiated thyroid cancer based on external dose-rate. Optimisation of the number of measurements

Objetivos. Comparar los resultados de la dosimetría individual en pacientes de cáncer diferenciado de tiroides tratados con 131I en nuestro centro con los límites dosimétricos establecidos y con resultados obtenidos en estudios publicados. Analizar el número óptimo de medidas a realizar para reducir el impacto de la dosimetría en el bienestar del paciente y, en segundo término, en la carga de trabajo del personal sanitario. Material y métodos. Se realiza la dosimetría a 29 pacientes del Servicio de Medicina Nuclear del Hospital Universitario y Politécnico La Fe, afectados de cáncer diferenciado de tiroides y tratados con actividades de entre 1,02 y 5,51 GBq (promedio de 2,68 GBq) de 131I. Para ello se utiliza el protocolo de la Sociedad Española de Física Médica (SEFM) basado en medidas de tasa de dosis externa ajustadas a una curva biexponencial, de acuerdo con un modelo de dos compartimentos. Para cada paciente se realizan distintas dosimetrías tomando diferentes selecciones de las medidas disponibles a fin de buscar el número óptimo. Resultados. Los resultados están muy por debajo de los límites dosimétricos y son coherentes con los obtenidos en otros centros. El número de medidas puede reducirse de 5, como propone el protocolo de la SEFM, a 4 sin pérdida de precisión significativa. Una mayor reducción de medidas puede justificarse en casos particulares. Conclusiones. Los valores obtenidos para las magnitudes dosimétricas quedan muy por debajo de los límites establecidos. Se puede asumir la reducción de medidas a costa de un aumento de la incertidumbre moderado beneficiando del paciente (AU)

Objectives. To compare the results of individual dosimetry in differentiated thyroid cancer patients treated with 131I at our centre with the established limits and dosimetry results of published studies. Analysis of the optimal number of measurements necessary to reduce the impact of dosimetry for the comfort of the patient and, secondly, on the workload of health workers. Material and methods. Dosimetry was performed in the Nuclear Medicine Department of the University and Polytechnic Hospital La Fe, on 29 patients suffering from differentiated thyroid cancer and treated with activities between 1.02 and 5.51 GBq (mean 2.68 GBq) of 131I. The Spanish Society of Medical Physics (SEFM) protocol was used, based on measurements of external dose rate adjusted to a bi-exponential curve according to a two compartment model. Different dosimetries were performed on each patient, taking different selections of the available measurements in order to find the optimal number. Results. Results are well below the dosimetry limits, and are consistent with those obtained in other centres. The number of measurements can be reduced from 5, as proposed in the SEFM protocol, to 4 without significant loss of accuracy. Further reducing measures may be justified in individual cases. Conclusions. The values obtained for the dosimetry quantities are significantly below the established limits. A reduction in measurements can be assumed at the cost of a moderate increase in uncertainty, benefiting the patient (AU)

131I treatment in Differentiated Thyroid Cancer and End-Stage Renal Disease / Tratamiento con 131I en pacientes con cáncer diferenciado de tiroides e insuficiencia renal terminal

Purpose. Radioiodine (RAI) is a cornerstone in the treatment of Differentiated Thyroid Cancer (DTC). In patients on haemodialysis due to End-Stage Renal Disease (ESRD), it must be used cautiously, considering the renal clearance of this radionuclide. Also, the safety of the procedure and subsequent long-term outcome is still not well defined. In 2001, we described a dosimetric method and short-term results in three patients, with a good safety profile. We hypothesize that our method is safe in a long-term scenario without compromising the prognosis of both renal and thyroid disease. Material and methods. Descriptive-retrospective study. A systematic search was carried out using our clinical database from 2000 to 2014. Inclusion criteria: DTC and radioiodine treatment while on haemodialysis. Exclusion criteria: peritoneal dialysis. Results. Final sample n = 9 patients (n = 5 males), age 48 years (median age 51 years males, 67 years female group); n = 8 papillary thyroid cancer, n = 1 follicular thyroid cancer; n = 5 lymph node invasion; n = 1 metastatic disease. Median RAI dose administered on haemodialysis 100 mCi. 7.5 years after radioiodine treatment on haemodialysis, n = 7 deemed free of thyroid disease, n = 1 persistent non-localised disease. No complications related to the procedure or other target organs were registered. After 3.25 years, n = 4 patients underwent successful renal transplantation; n = 4 patients did not meet transplantation criteria due to other conditions unrelated to the thyroid disease or its treatment. One patient died due to ischemic cardiomyopathy (free of thyroid disease). Conclusions. Radioiodine treatment during haemodialysis is a long-term, safe procedure without worsening prognosis of either renal or thyroid disease (AU)

El tratamiento con radioyodo (RAI) es fundamental en el tratamiento del carcinoma diferenciado de tiroides (DTC). En pacientes en hemodiálisis por enfermedad renal terminal (ESRD), debe usarse con cautela, considerando el aclaramiento renal de este radionúclido. Además, aún no está bien definida la seguridad y la evolución a largo plazo tras el procedimiento en estas circunstancias. En 2001, describimos un método dosimétrico con resultados a corto plazo en tres pacientes, con buen perfil de seguridad. Creemos que este método es seguro a largo plazo sin comprometer el pronóstico de la enfermedad renal o tiroidea. Métodos. Estudio descriptivo retrospectivo. Realizamos una búsqueda sistemática en base de datos clínica entre los años 2000-2014. Criterios de inclusión: Tratamiento ablativo con radioyodo en paciente en hemodiálisis. Se excluyó la diálisis peritoneal. Resultados. Muestra final n = 9 pacientes (n = 5 varones), edad 48 años (Mediana 51 en varones, 67 en mujeres); n = 8 carcinoma papilar, n = 1 folicular; n = 5 invasión ganglionar; n = 1 enfermedad metastásica. Mediana de actividad (RAI) administrada 100 mCi. 7.5 años tras el tratamiento, n = 7 se consideraron libres de enfermedad, y n = 1 con enfermedad persistente no localizada. No se registraron complicaciones relacionadas con el procedimiento. Tras 3.25 años, n = 4 se sometieron a trasplante renal; n = 4 no cumplieron criterios de trasplante por motivos no relacionados con la enfermedad tiroidea o el procedimiento. Un paciente falleció por cardiopatía isquémica (libre de enfermedad). Conclusiones. El tratamiento con radioyodo en hemodiálisis es seguro a largo plazo sin que empeore el pronóstico de la enfermedad renal o la tiroidea (AU)

Eficacia y complicaciones en el empleo de prótesis autoexpandibles de colon: análisis de un periodo de 15 años / Efficacy and complications in the use of self-expanding colonic stents: an analysis of 15 years’ experience

Objetivo. Analizar la eficacia y seguridad del procedimiento para colocar las prótesis autoexpandibles de colon. Evaluar los factores asociados a complicaciones. Realizar un análisis dosimétrico del procedimiento. Material y métodos. Realizamos un estudio descriptivo retrospectivo unicéntrico de 478 procedimientos para colocar prótesis metálicas autoexpandibles de colon. Se insertaron 423 prótesis de nitinol y 79 de acero inoxidable. Incluimos todas las obstrucciones de colon, 446 de etiología maligna y 8 de causa benigna. Excluimos los pacientes con perforación intestinal, hemorragia grave del colon, esperanza de vida corta y lesiones situadas a menos de 5 cm del ano. Analizamos el éxito técnico, éxito clínico, las complicaciones durante el seguimiento y recogimos los datos dosimétricos. Resultados. Se obtuvo éxito técnico en un 92,26% (n = 441), éxito clínico en un 78,45% (n = 375) y un porcentaje de complicaciones durante el seguimiento del 18,5%. Las prótesis de acero tuvieron más complicaciones (OR: 3,2; IC 95%: 1,8-5,7). El valor medio de producto dosis por área fue 35 Gy.cm2. El de tiempo de fluoroscopia (p = 0,001), producto dosis por área (p = 0,029) y kerma (p = 0,001) fueron mayores si el procedimiento fue realizado exclusivamente por fluoroscopia, en vez de conjuntamente por el endoscopista y el radiólogo intervencionista. Conclusión. El procedimiento para colocar prótesis autoexpandibles de colon es eficaz y seguro, con una tasa aceptable de complicaciones. Las dosis de radiación fueron bajas, con menos dosis y tiempos de fluoroscopia cuando el procedimiento se realizó de manera conjunta con el endoscopista (AU)

Objective. To analyze the efficacy and safety of the procedure for placing self-expanding stents in the colon. To evaluate the factors associated with complications. To analyze the dose of radiation delivered in the procedure. Material and methods. This was a retrospective descriptive study of 478 procedures done at a single center to place self-expanding metallic stents in the colon. A total of 423 nitinol stents and 79 stainless steel stents were placed. We included all colonic obstructions, of which 446 had malignant causes and 8 had benign causes. We excluded patients with intestinal perforation, severe colonic bleeding, short life expectancy, or lesions located less than 5 cm from the anus. We collected the dosimetric data and analyzed the technical success, clinical success, and complications during follow-up. Results. The procedure was a technical success in 92.26% of cases (n = 441) and a clinical success in 78.45% (n = 375); complications occurred during follow-up in 18.5% of cases. Complications occurred more frequently with the stainless steel stents than with the nitinol stents (OR: 3.2; 95% CI: 1.8-5.7). The mean value of the dose area product was 35 Gy*cm2. When instead of being done by the interventional radiologist working together with an endoscopist the procedure was done exclusively by the interventional radiologist, the time under fluoroscopy (p = 0.001), dose area product (p = 0.029), and kinetic energy released per unit mass (p = 0.001) were greater. Conclusion. The procedure for placing self-expanding colonic stents is efficacious and safe with an acceptable rate of complications. The doses of radiation delivered were low, and the radiation doses and time under fluoroscopy were lower when the procedure was done together with an endoscopist (AU)

Radioprotección en quirófanos de traumatología: ¿en qué situación estamos? / Radiation safety in orthopaedic operating theatres. what is the current situation?

Objetivo. Analizar la exposición a radiaciones ionizantes por parte de dos cirujanos ortopédicos en su práctica diaria y revisar las principales recomendaciones nacionales e internacionales al respecto. Material y método. Se efectúo un estudio retrospectivo de la actividad quirúrgica con uso de fluoroscopia realizado por dos cirujanos ortopédicos en un año. Se calculó la radiación recibida basándose en mediciones por procesos publicados en la bilbliografía. Revisión bibliográfica de recomendaciones y normativas internacionales. Resultado. La radiación recibida en un año por los dos cirujanos ortopédicos no sobrepasó el límite de la legislación actual ni el de las nuevas recomendaciones europeas e internacionales. La exposición fue asimétrica, siendo las manos la zona más radiada. Las nuevas recomendaciones rebajan los niveles permitidos de radiación en ojos. Discusión. La estimación de radiación recibida hace necesario proteger y vigilar especialmente las manos y los ojos. Son necesarios conocimientos del funcionamiento del fluoroscopio y de las medidas de radioprotección (AU)

Objective. To analyse the exposure of two Orthopaedic Surgeons to ionizing radiations in their daily work, and to review the main national and international recommendations on this subject. Material and methods. A retrospective study was conducted on the surgical treatments that use fluoroscopy performed by two Orthopaedic Surgeons during a one year period. An evaluation was made of the radiation received, based on measurements of the processes published in the bibliography section. A literature review of international recommendations and regulations is also presented. Results. The radiation received by the two Orthopaedic Surgeons during one year did not exceed the limits of present-day legislation or the new European and international recommendations. The exposure was asymmetrical, with the hands being the most radiated part. The new recommendations reduce the permitted level of radiation on eyes. Discussion. The evaluation of the radiation received demonstrates the need for radiation protection, paying particular attention to the hands and eyes. Good knowledge of operating a fluoroscope and radiation safety measures are also essential (AU)

Estimativa dos valores de MSAD em procedimentos de tomografia computadorizada utilizando filmes radiocrômicos / Estimation of MSAD values in computed tomography scans using radiochromic films

OBJETIVO: Verificar a viabilidade de filmes radiocrômicos como um dosímetro alternativo para estimativa da dose média em cortes múltiplos a partir dos perfis de kerma.MATERIAIS E MÉTODOS: Os filmes foram distribuídos em cilindros posicionados no centro e nas regiões periféricas de um objeto simulador padrão de abdome utilizado para dosimetria em tomografia computadorizada.RESULTADOS: Os valores de dose média em cortes múltiplos calculados foram 13,6 ± 0,7, 13,5 ± 0,7 e 18,7 ± 1,0 mGy para os valores de passo (pitch) de 0,75, 1,00 e 1,50, respectivamente.CONCLUSÃO: Apesar de os resultados mostrarem valores menores que o nível de referência de radiodiagnóstico de 25 mGy estabelecido pela legislação brasileira para exames de abdome, eles sugerem que há espaço para otimização dos procedimentos e uma revisão do valor para o nível de referência de radiodiagnóstico brasileiro.

OBJECTIVE: To evaluate the feasibility of using radiochromic films as an alternative dosimeter to estimate the multiple scan average dose on the basis on kerma profiles.MATERIALS AND METHODS: The radiochromic films were distributed in cylinders positioned in the center and in four peripheral bores of a standard abdominal phantom utilized for computed tomography dosimetry.RESULTS: Values for multiple scan average dose values corresponded to 13.6 ± 0.7, 13.5 ± 0.7 and 18.7 ± 1.0 mGy for pitch of 0.75, 1.00 and 1.50, respectively.CONCLUSION: In spite of results showing lower values than the reference level for radiodiagnosis (25 mGy) established by the Brazilian regulations for abdominal studies, it is suggested that there is room to optimize procedures and review the reference level for radiodiagnosis in Brazil.

Estudo da dose nos exames de tomografia computadorizada abdominal em um equipamento de 6 cortes / Dosimetry in abdominal imaging by 6-slice computed tomography

OBJETIVO: Determinar a dose efetiva recebida nos exames de tomografia computadorizada abdominal e estudar a influência das características dos pacientes na dose recebida. MATERIAIS E MÉTODOS: Foram realizadas medições dos valores de dose com uma câmara de ionização em objetos simuladores, de forma a verificar se os valores obtidos estavam de acordo com os valores apresentados pelo equipamento de tomografia computadorizada e se estes não ultrapassavam os níveis de referência de dose recomendados. Posteriormente, foram medidos os valores de dose recebida pelos pacientes, com autonomia física, nos exames de tomografia computadorizada abdominal (n = 100) e a relação existente com as suas características antropométricas. Por último, foi simulada a dose nos órgãos por meio do método de Monte Carlo utilizando o software de simulação CT-Expo V 1.5, e estudado o efeito do controle automático de exposição nestes exames. RESULTADOS: As principiais características com influência direta na dose são a massa corporal, o perímetro abdominal e o índice de massa corporal do paciente, cuja relação é linear e positiva. CONCLUSÃO: A dose de radiação recebida nos exames abdominais depende de algumas características dos pacientes, sendo importante ajustar os parâmetros de aquisição às suas dimensões.

OBJECTIVE: To determine the effective dose in abdominal computed tomography imaging and to study the influence of patients' characteristics on the received dose. MATERIALS AND METHODOS: Dose values measurements were performed with an ionization chamber on phantoms to check the agreement between dose values and those presented by the computed tomography apparatus, besides their compliance with the recommended reference dose levels. Later, values of dose received by physically able patients submitted to abdominal computed tomography (n = 100) were measured and correlated with their anthropometric characteristics. Finally, the dose to organs was simulated with the Monte Carlo method using the CT-Expo V 1.5 software, and the effect of automatic exposure control on such examinations. RESULTS: The main characteristics directly influencing the dose include the patients' body mass, abdominal perimeter and body mass index, whose correlation is linear and positive. CONCLUSION: The radiation dose received from abdominal CT scans depends on some patient's characteristics, and it is important to adjust the acquisition parameters to their dimensions.

Caracterização dosimétrica de feixes de fótons com detector de diamante / Dosimetric characterization of photon beams using a diamond detector

OBJETIVO: Este trabalho foi realizado com o objetivo de caracterizar o detector de diamante, bem como observar seu comportamento. MATERIAIS E MÉTODOS: As características dosimétricas de feixes de fótons de 6 MV de energia foram medidas utilizando o sistema automático de varredura MP3 da PTW com um detector de diamante e foram comparadas com medidas usando uma câmara de ionização 31010 da PTW. RESULTADOS: As características dosimétricas do detector de diamante foram observadas por meio de medidas de linearidade com a dose, dependência com a taxa de dose e distribuições de dose em profundidade, bem como perfis. CONCLUSÃO: Algumas medidas com diamante e câmara de ionização foram validadas com resultados publicados na literatura, o que demonstrou um bom comportamento do detector de diamante na comparação com a câmara de ionização, muito utilizada para dosimetria em radioterapia, evidenciando que o diamante é uma boa escolha de detector para dosimetria de campos pequenos.

OBJECTIVE: The present study was aimed at characterizing a diamond detector and observing its behavior. MATERIALS AND METHODS: The dosimetric characteristics of 6 MV photon beams were measured by utilizing an automatic PTW MP3 scanning system with a diamond detector, and compared with measurements performed with a PTW 31010 ion chamber. RESULTS: Measurements of dose linearity, dose rate dependence and depth dose distribution as well as dose profiles demonstrated the dosimetric characteristics of the diamond detector. CONCLUSION: Some measurements with diamond detector and ion chamber were validated with results published in the literature, demonstrating a good behavior of the diamond detector as compared with the ionization chamber that is widely utilized for dosimetry in radiotherapy, indicating that the diamond detector is a good choice for small field dosimetry.

Resultados de implante de semillas de iodo-125 con sistema de preplanificación en 250 pacientes con carcinoma de próstata / Results of 125-Iodine seed implant with preplanning system in 250 patients with prostate cancer

Objetivo: Revisar la experiencia con implantes permanentes de semillas de I-125 en carcinoma de próstata y el resultado a los 8 años de comenzar la técnica. Material y métodos: De 2002 a 2007 hemos realizado 250 implantes con braquiterapia de baja tasa con RapidStrand® y sistema de preplanificación. La edad media fue 68 años (49-78). El PSA medio fue 7,32 (2,31-14,6), 98% T1-T2a, 96% Gleason ≤ 6, 81% de bajo riesgo y 19% de riesgo intermedio (10 de estos últimos recibieron 46 Gy de radioterapia externa). Un 42% recibieron hormonoterapia. Resultados: Con seguimiento medio de 48 meses, 14 pacientes (5,7%) tuvieron recaída bioquímica (RB). En 11 pacientes (4,5%) con teórica RB el PSA descendió espontáneamente sin tratamiento. La supervivencia actuarial sin recaída bioquímica a 5 años fue del 91% (92% bajo riesgo, 86% riesgo intermedio); 92 vs 81% en pacientes con PSA < 10 vs > 10 (p < 0,05). Hubo complicaciones rectales G2 en el 0,6%, sondaje vesical en un 6,5%; el 60% conservaron la función sexual. El V100 medio fue del 89% y el D90 143 Gy. Conclusión: El resultado en carcinoma de próstata de bajo riesgo mediante semillas de Iodo-125es muy bueno con muy pocas complicaciones. Las elevaciones de PSA deberían ser controladas antes de dar tratamiento de rescate (AU)

Introduction: We review the experience with prostate carcinoma patients treated with permanent implants of 125-I seeds and the outcome eight years after the beginning of this technique. Material and methods: From 2002 to 2007 we have performed 250 implants with LDR brachytherapy with RapidStrand® and preplanning system. Mean age was 68 (49-78). Mean PSA was 7.32 (2.31 - 14.6). T1-T2a was the stage in 98%, and Gleason ≤ 6 in 96%. Low risk cases were 81% and intermediate risk 19% (ten of them received 46 Gy EBRT). Hormonal treatment was used in 42%. Results: With a mean follow-up of 48 months, 14 patients (5.7%) showed biochemical failure (BF). Eleven patients (4.5%) with theoretical BF were observed and PSA decreased without treatment. Actuarial PSA relapse-free survival at 5 years was 91%, (92% low risk, 86% intermediate cases), and 92% vs 81% with PSA <10 vs >10 (p < 0.05). Rectum complications were G2 in0 .6%. A urinary catheter was necessary in 6.5%. Sexual function was conserved in 60%. Mean V100 was 89% and D90 143 Gy. Conclusion: The outcome of patients with low risk prostate carcinoma treated with I-125 seed is very good with very low complications rate. Cases with PSA bounces should be controlled before starting a salvage treatment (AU)