[Nuclear medicine and radiopharmaceuticals]. / Medicina nuclear y radiofármacos.

Nuclear Medicine is a medical specialty that allows modern diagnostics and treatments using radiopharmaceuticals original radiotracers (drugs linked to a radioactive isotope). In Europe, radiopharmaceuticals are considered a special group of drugs and thus their preparation and use are regulated by a set of policies that have been adopted by individual member countries. The radiopharmaceuticals used in diagnostic examinations are administered in very small doses. So, in general, they have no pharmacological action, side effects or serious adverse reactions. The biggest problem associated with their use are the alterations in their biodistribution that may cause diagnostic errors. Nuclear Medicine is growing considerably influenced by the appearance and development of new radiopharmaceuticals in both the diagnostic and therapeutic fields and primarily to the impact of new multimodality imaging techniques (SPECT-CT, PET-CT, PET-MRI, etc.). It's mandatory to know the limitations of these techniques, distribution and eventual physiological alterations of radiopharmaceuticals, contraindications and adverse reactions of radiological contrasts, and the possible interference of both.

[Determination of dose calibrator setting of the capintec CRC-35R for samarium-153]. / Determinación del factor de calibración para el samario-153 en el activímetro de dosis CRC-35R.

OBJECTIVE: The aim of this work is to determine the calibration factor for Sm-153 and evaluate the influence of the geometry in the activity measurements in order to administer accurately the activity to the patient. METHODS: The calibration factor for Sm-153 was determinated using the Sm-153 sources commonly used in clinical practice and the calibrator response in a known calibration setting. The geometry correction factor for the vial and the plastic syringe was calculated using the real activity indicated by the manufacturer and the activity measured in the vial and in the plastic syringe. RESULTS: The calibration factor obtained is 239 +/- 4 and the correction factor which takes in consideration the geometry is 0,87 +/- 0,07. The activity measured in the syringe is eighteen percent higher to activity measured in the vial. CONCLUSION: This method allows to measure accurately the activity of Sm-153 in vial and syringe applying this geometry correction factor to determine accurately the activity administered to the patient.

[Sentinel lymph node in tumors of the larynx: technique and results]. / El ganglio centinela en tumores de laringe: técnica y resultados obtenidos.

OBJECTIVES: To evaluate the applicability of sentinel node biopsy in NO carcinomas of the larynx. MATERIALS AND METHODS: We carried out a prospective study in 19 patients with carcinoma of the larynx NO. We peritumorally infiltrate with 1 mCi 99mTc-labeled nanocolloidal albumin via rigid endoscopy in general anaesthesia. Sentinel node detection is performed with a gamma sonda during lymph node detection. The histological results of the sentinel node are compared with the excised neck dissection specimen. RESULTS: Identification of sentinel node was successful in 17 patients (89.47%). In 11 patients the sentinel node was tumor negative reflecting the correct neck lymph node status (pNO). Three patients had metastases in the sentinel node. We observed three false- negative. The sensitivity of the technique was 50% (3/6) and the negative predictive value 78.6%. CONCLUSIONS: We think that more studies are needed to use the technique in the laryngeal cancer and that a correct selection of the patients is essential.

[Sentinel node in tumours of the lip and the oral cavity]. / Estudio del ganglio centinela en tumores de labio y cavidad oral.

OBJECTIVES: This study shows the results obtained by the application of the sentinel node (SN) in oral and lip cancer and performs a lymphatic map of these tumours. PATIENTS AND METHOD: We prospectively studied 14 patients with lip and oral tumours, all of them N0. We injected colloidal particles of serum albumin labeled with Tc-99 peritumoraly and we located the SN intraoperatively. The SN was then sent for anatomopathological study. RESULTS: Sentinel node was identified in all of the patients. In 11 of them the sentinel node was negative for metastases and correctly predicted the status of the neck. In 3 patients the sentinel node was the only node that contained metastases. There were no false negatives. The sensibility of the technique was 100%. CONCLUSIONS: The results showed that this technique is a feasible method for tumours in these locations and can avoid neck dissections in N0 patients.

Value of radionuclide oesophageal transit in studies of functional dysphagia.

Radionuclide oesophageal transit time was evaluated in 70 individuals, divided into three groups: normal individuals, patients with non-organic dysphagia and patients with primary oesophageal motility disorders treated with per-endoscopic forced pneumatic dilatation. In all of them the oesophageal transit time of a bolus of water with 18.5 MBq (500 microCi) of 99Tmc sulphur colloid was assessed, as was the percentage of residual activity of the bolus in the oesophagus. There was a significant difference in these parameters between the control group and the group with non-organic dysphagia, the diagnostic capacity of this test being 93% sensitivity, 100% specificity, 100% positive predictive value and 90% negative predictive value, which suggests its inclusion in diagnostic protocols of dysphagias. In patients with primary oesophageal motility disorders, a significant decrease in values of residual activity has been observed after treatment with per-endoscopic forced pneumatic dilatation.

[Radioisotopic synoviorthesis in rheumatoid arthritis. A study of 108 cases]. / La sinoviortesis radioisotópica en la artritis reumatoide. Estudio de 108 casos.

There are several therapeutic alternatives in the local treatment of rheumatoid arthritis (RA): intraarticular corticosteroids, chemical synoviorthesis, surgical synovectomy and synoviorthesis with radioisotopes. We present the results of an observational study on radioisotopic synoviorthesis carried out in the Valencian health care area from January 1989 to May 1997 which included 108 synoviortheses performed in 51 patients. This study aimed to assess the efficacy and safety of radiosynoviorthesis in the treatment of RA which had not responded to conventional treatment. Good and moderate results were obtained in 76.2% of the cases, there being significant differences in the efficacy of synoviorthesis in patients with and without advanced radiographic alterations. There were few side effects (3.7%). We conclude that radiosynoviortesis is a useful and safe therapeutic tool in RA that does not respond to conventional treatment, that it is more effective in large joints with little cartilaginous deterioration and that its repeated use does not decrease the expected therapeutic effect.

[Scintigraphy with labelled leukocytes in acute pancreatitis. Preliminary results]. / Gammagrafía con leucocitos marcados en la pancreatitis aguda. Resultados preliminares.

This study aims to evaluate the contribution of the 99mTc-HMPAO labelled leukocyte in the prognostic assessment of patients with acute pancreatitis. We have compared the usual methods of prognostic evaluation (computed tomography CT and the Ranson clinical score scale) with the scintigraphic findings in 23 consecutive patients with a clinical diagnosis of mild or severe acute pancreatitis. All 6 patients with severe pancreatitis showed an uptake which was mostly mild. 9/17 patients with mild pancreatitis showed uptake, which also frequently had a low intensity. When the severity index of CT was compared with the leukocyte results, the only patient with a high severity index showed a grade 3 uptake. However, in over 50% of the patients with a low severity index, uptake, generally having a low intensity, was found. When the uptake degree was compared with the Ranson score level, we observed a predominance of mild uptake in both patients with mild and severe pancreatitis. Considering these results, we believe that the lack of uptake in the leukocyte study in a patient with acute pancreatitis can be interpreted as a good prognosis sign. The significance of the finding of uptake in the pancreatic area is uncertain and studies should be performed in larger sized samples.

Medicina nuclear y radiofármacos / Nuclear medicine and radiopharmaceuticals

La medicina nuclear es una moderna especialidad médica que permite realizar diagnósticos y tratamientos mediante la utilización de radiofármacos o radiotrazadores (fármacos unidos a un isótopo radioactivo). En Europa los radiofármacos se consideran un grupo especial de medicamentos y, por tanto, su preparación y su uso están regulados por un conjunto de directivas que han sido adoptadas por los distintos países miembros. Los radiofármacos que se emplean en las exploraciones diagnósticas se administran en dosis muy pequeñas por lo que, en general, no tienen ninguna acción farmacológica, ni efectos secundarios, ni reacciones adversas graves. El mayor problema asociado a su utilización son las alteraciones de su biodistribución, lo cual puede condicionar errores diagnósticos. La medicina nuclear está experimentando un notable crecimiento condicionado por la aparición y desarrollo de nuevos radiofármacos, tanto en el campo diagnóstico como en el terapéutico, y fundamentalmente por el impacto de las nuevas técnicas de imagen multimodalidad (SPECT-TC, PET-TC, PET-RM, etc.). Es necesario conocer las limitaciones de estas técnicas, la distribución fisiológica y las posibles alteraciones de los radiofármacos, las contraindicaciones y las reacciones adversas de los contrastes radiológicos, así como la posible interferencia de ambos (AU)

Nuclear Medicine is a medical specialty that allows modern diagnostics and treatments using radiopharmaceuticals original radiotracers (drugs linked to a radioactive isotope). In Europe, radiopharmaceuticals are considered a special group of drugs and thus their preparation and use are regulated by a set of policies that have been adopted by individual member countries. The radiopharmaceuticals used in diagnostic examinations are administered in very small doses. So, in general, they have no pharmacological action, side effects or serious adverse reactions. The biggest problem associated with their use are the alterations in their biodistribution that may cause diagnostic errors. Nuclear Medicine is growing considerably influenced by the appearance and development of new radiopharmaceuticals in both the diagnostic and therapeutic fields and primarily to the impact of new multimodality imaging techniques (SPECT-CT, PET-CT, PET-MRI, etc.). It's mandatory to know the limitations of these techniques, distribution and eventual physiological alterations of radiopharmaceuticals, contraindications and adverse reactions of radiological contrasts, and the possible interference of both (AU)

Determinación del factor de calibración para el samario-153 en el activímetro de dosis CRC®-35R / Determination of dose calibrator setting of the capintec CRC®-35R for samarium-153

Determination of dose calibrator setting of the capintec CRC®-35R for samarium-153 Objetivo. Determinar el factor de calibración del activímetro para el radionucleido samario-153 (153Sm) y estudiar la influencia de la geometría en la medida de la actividad, de forma que se pueda determinar con exactitud la actividad administrada al paciente.Material y métodos. El factor de calibración del actinímetro para el 153Sm se determinó a partir del valor medio de la respuesta del detector en un canal de factor de calibración conocido, utilizando fuentes de 153Sm de uso clínico. El factor de corrección según geometría se calculó a partir del valor de actividad real indicada por el fabricante y las medidas de actividad realizadas en vial y jeringa. Resultados. El factor de calibración obtenido es de 239 ± 4. El factor de corrección que tiene en cuenta la geometría es de 0,87 ± 0,07. La actividad medida en jeringa es un 18 % superior a la medida en vial. Conclusiones. El método empleado permite medir correctamente la actividad de 153Sm, tanto en vial como en jeringa para dosificar con exactitud la actividad de Samario [153Sm] lexidronam administrada al paciente

Objetive. The aim of this work is to determine the calibration factor for Sm-153 and evaluate the influenceof the geometry in the activity measurements in order to administer accurately the activity to the patient.Methods. The calibration factor for Sm-153 was determinated using the Sm-153 sources commonly used in clinical practice and the calibrator response in a known calibration setting. The geometry correction factor for the vial and the plastic syringe was calculated using the real activity indicated by the manufacturer and the activity measured in the vial and in the plastic syringe.Results. The calibration factor obtained is 239 ± 4 and the correction factor which takes in consideration the geometry is 0,87 ± 0,07. The activity measured in the syringe is eighteen percent higher to activity measured in the vial. Conclusion. This method allows to measure accurately the activity of Sm-153 in vial and syringe applying this geometry correction factor to determine accurately the activity administered to the patient (AU)

El ganglio centinela en tumores de laringe: técnica y resultados obtenidos / Sentinel lymph node in tumors of the larynx: technique and results

Objetivos: Determinar la aplicabilidad de la técnica del ganglio centinela (GC) en tumores N0 de laringe. Material y métodos: Realizamos un estudio prospectivo en 19 pacientes con tumores N0 de laringe. Infiltramos peritumoralmente 1mCi de nanocoloides de albúmina marcados con 99mTc con endoscopio rígido bajo anestesia general. Detectamos el GC intraoperatoriamente con una sondagamma durante el vaciamiento cervical. Los resultados histológicos del GC se comparan con los del vaciamiento cervical. Resultados: Identificamos el GC en 17 pacientes (89,47%). Once pacientes presentaron GC libres de tumor, reflejando correctamente el estatus del cuello (pN0). Tres pacientes presentaron metástasis en el GC l. Encontramos 3 falsos negativos. La sensibilidad de la técnica fue 50,0% (3/6) y el VPN de un 78,6%. Conclusiones: Pensamos que para que la técnica del GC sea aplicable en tumores de laringe se precisan de un mayor número de estudios, siendo fundamental la realización de un correcta selección de los pacientes

OBJECTIVES: To evaluate the applicability of sentinel node biopsy in NO carcinomas of the larynx. MATERIALS AND METHODS: We carried out a prospective study in 19 patients with carcinoma of the larynx NO. We peritumorally infiltrate with 1 mCi 99mTc-labeled nanocolloidal albumin via rigid endoscopy in general anaesthesia. Sentinel node detection is performed with a gamma sonda during lymph node detection. The histological results of the sentinel node are compared with the excised neck dissection specimen. RESULTS: Identification of sentinel node was successful in 17 patients (89.47%). In 11 patients the sentinel node was tumor negative reflecting the correct neck lymph node status (pNO). Three patients had metastases in the sentinel node. We observed three false- negative. The sensitivity of the technique was 50% (3/6) and the negative predictive value 78.6%. CONCLUSIONS: We think that more studies are needed to use the technique in the laryngeal cancer and that a correct selection of the patients is essential

Carcinoma bronquioloalveolar como causa potencial de falso negativo con PET-FDG / Bronchioloalveolar carcinoma as potencial cause of false negative with PET-FDG

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Estudio del ganglio centinela en tumores de labio y cavidad oral / Sentinel node in tumours of the lip and the oral cavity

Objetivos: Este estudio muestra los resultados obtenidos mediante la aplicación del ganglio centinela en tumores de labio y cavidad oral; elaboramos un mapa linfográfico de dichos tumores. Material y método: Estudiamos prospectivamente 14 pacientes con tumores de labio y cavidad oral N0 clínicos. Inyectamos de forma peritumoral, 1 mCi de nanocoloides de albúmina marcada con Tc99 preoperatoriamente, para posteriormente localizar el ganglio centinela. Una vez localizado éste, se envía separadamente del resto de cadenas ganglionares para su estudio anatomopatológico. Resultados: En todos los pacientes se identificó el ganglio centinela. En 11 casos el ganglio centinela fue negativo para metástasis prediciendo correctamente el estadio cervical. En 3 casos el ganglio centinela fue el único ganglio que contenía metástasis. No hubo ningún caso de falso negativo. La sensibilidad de la técnica fue del 100%. Conclusiones: Los resultados muestran esta técnica como un método fiable en esta localización que podría evitar los vaciamientos cervicales en pacientes N0 clínicos

Objectives: This study shows the results obtained by the application of the sentinel node (SN) in oral and lip cancer and performs a lymphatic map of these tumours. Patients and method: We prospectively studied 14 patients with lip and oral tumours, all of them N0. We injected colloidal particles of serum albumin labeled with Tc-99 peritumoraly and we located the SN intraoperatively. The SN was then sent for anatomopathological study. Results: Sentinel node was identified in all of the patients. In 11 of them the sentinel node was negative for metastases and correctly predicted the status of the neck. In 3 patients the sentinel node was the only node that contained metastases. There were no false negatives. The sensibility of the technique was 100%. Conclusions: The results showed that this technique is a feasible method for tumours in these locations and can avoid neck dissections in N0 patients