Impacto de la tomografía por emisión de positrones mediante 18-Fluoro-2-Desoxi-D-Glucosa (PET-FDG) en el manejo terapéutico de pacientes con recurrencia secundaria a cáncer de ovario / Impact of positron emission tomography with FDG-PET in treatment of patients with suspected recurrent ovarian cancer

Objetivo: La detección de la recurrencia secundaria a cáncer de ovario es un problema de importancia notoria, pudiendo mediante un diagnóstico correcto ofrecer alternativas útiles en el manejo de las pacientes. El objetivo de este estudio ha sido valorar el impacto terapéutico de la PET-FDG en la recurrencia por cáncer de ovario. Material y métodos: Se han incluido 43 enfermas con cáncer de ovario en las que se efectuó el estudio PET-FDG ante la sospecha diagnóstica de recidiva. Los resultados de la PET-FDG se confirmaron por histopatología y seguimiento clínico mayor de 12 meses. Se ha comparado el impacto en el manejo de las pacientes basado en los métodos convencionales de imagen, con el plan de tratamiento considerando los hallazgos de la PET-FDG, clasificando el impacto de la PET-FDG como alto, medio, bajo o no impacto. Los cambios en el manejo terapéutico de las enfermas, han sido clasificados como intermodalidad o intramodalidad. Resultados: El estudio PET-FDG obtuvo un impacto alto en el manejo terapéutico de 28 pacientes (65,1 %), un impacto medio en 2 pacientes (4,6 %), un impacto bajo en 9 pacientes (20,9 %), y no tuvo impacto en 4 enfermas (9,3 %). La PET-FDG indujo un cambio intermodalidad en 27 pacientes (62,8 %); un cambio intramodalidad en 3 pacientes (7 %); y finalmente en 13 enfermas (30,2 %), no produjo ningún cambio en el tratamiento. Conclusiones: La PET-FDG proporciona una información adicional con respecto a los métodos diagnósticos de imagen convencional, permitiendo efectuar cambios en el manejo terapéutico en la mayoría de las enfermas

Aim: Recurrent ovarian cancer is a major problem and an accurate diagnosis can often change patients' management. This study aimed to assess the impact on management of FDG-PET in recurrent ovarian cancer. Material and methods: Forty-three patients in whom FDG-PET scan was performed due to suspected recurrent ovarian cancer were included. FDG-PET results were confirmed by histopathology and clinical follow-up of at least 12 months. To assess impact on management the treatment plan based on conventional imaging methods was compared with the treatment plan based on inclusion of PET findings, classifying FDG-PET impact on management as high, medium, low or no impact. Management changes, when present, were classified as intermodality or intramodality. Results: FDG-PET had a high impact on therapeutic management in 28 patients (65.1 %), medium impact in 2 patients (4.6 %), low impact in 9 patients (20.9 %), and no impact in 4 patients (9.3 %). FDG-PET induced an intermodality change in management in 27 patients (62,8 %); intramodality changes were induced in 3 patients (7 %). Finally, it produced no treatment changes in 13 patients (30.2 %). Conclusion: FDG-PET supplied additional information when compared to conventional diagnostic procedures and allowed adequate management changes in most patients

[Impact of positron emission tomography with FDG-PET in treatment of patients with suspected recurrent ovarian cancer]. / Impacto de la tomografía por emisión de positrones mediante 18-Fluoro-2-Desoxi-D-Glucosa (PET-FDG) en el manejo terapéutico de pacientes con recurrencia secundaria a cáncer de ovario.

AIM: Recurrent ovarian cancer is a major problem and an accurate diagnosis can often change patients' management. This study aimed to assess the impact on management of FDG-PET in recurrent ovarian cancer. MATERIAL AND METHODS: Forty-three patients in whom FDG-PET scan was performed due to suspected recurrent ovarian cancer were included. FDG-PET results were confirmed by histopathology and clinical follow-up of at least 12 months. To assess impact on management the treatment plan based on conventional imaging methods was compared with the treatment plan based on inclusion of PET findings, classifying FDG-PET impact on management as high, medium, low or no impact. Management changes, when present, were classified as intermodality or intramodality. RESULTS: FDG-PET had a high impact on therapeutic management in 28 patients (65.1 %), medium impact in 2 patients (4.6 %), low impact in 9 patients (20.9 %), and no impact in 4 patients (9.3 %). FDG-PET induced an intermodality change in management in 27 patients (62,8 %); intramodality changes were induced in 3 patients (7 %). Finally, it produced no treatment changes in 13 patients (30.2 %). CONCLUSION: FDG-PET supplied additional information when compared to conventional diagnostic procedures and allowed adequate management changes in most patients.

[Positron emission tomography using 18-FDG-PET in radiologically indeterminate pulmonary lesions]. / Tomografía por emisión de positrones mediante PET-18FDG en lesiones pulmonares radiológicamente indeterminadas.

OBJECTIVE: Fluorine-18 deoxyglucose Positron Emission Tomography (FDG-PET) is a non-invasive technique that offers the possibility to define if the radiologically indetermined pulmonary lesions are benign or malignant with high positive and negative predictive values. Considering the indexed literature we can observe that there are few original studies performed with the diagnostic possibilities of our means. For this reason, our main objective is to evaluate the diagnostic accuracy of positron emission tomography in sixty-seven radiologically indetermined pulmonary nodular lesions. MATERIAL AND METHOD: Retrospectively, we evaluated the diagnostic ability of FDG-PET globally (by means of visual and semiquantitative analysis) and partially (only considering the Standardized Uptake Value (SUV)), in sixty-seven patients confirmed by pathology or clinical and radiological monitoring, in a time interval superior to one year. RESULTS: Globally, FDG-PET had a sensitivity (S) of 92%, specificity (SP) of 86.6%, positive predictive value (PPV) of 89.4%, negative predictive value (NPV) of 89.6% and diagnostic accuracy (DA) of 89%. The best results were obtained for an SUV equal or superior to 2.5. With this value, the clinical efficacy parameters were: S 0.92, SP 0.90, PPV 0.92, NPV 0.90 and DA 0.91. CONCLUSIONS: We can characterize most of the radiologically indetermined pulmonary lesions by FDG-PET. The additional use of SUV facilitates an increase in the positive predictive value and specificity of FDG-PET.

Tomografía por emisión de positrones mediante PET-18FDG en lesiones pulmonares radiológicamente indeterminadas / Positron emission tomography with 18fdg-pet in the radiologically indeterminated pulmonary lesions

Objetivo: La Tomografía por Emisión de Positrones con 18-fluoro-2desoxi-D-glucosa (PET-FDG) es una técnica no-invasiva, que nos ofrece la posibilidad de caracterizar la benignidad o malignidad de las lesiones pulmonares (NPS) radiológicamente indeterminadas, con un elevado valor predictivo negativo y positivo. Observando las publicaciones indexadas podemos apreciar que son escasas las realizadas con las posibilidades diagnósticas de PET-FDG. Por eso, nuestro objetivo es analizar la exactitud diagnóstica (ED), de la PET en nuestra experiencia con 67 pacientes con lesiones nodulares radiológicamente indeterminadas. Material y método: retrospectivamente, se ha valorado la aportación diagnóstica de la PET, de forma global (mediante análisis visual y semicuantitativo) y parcial (considerando únicamente el valor del SUV), en 67 pacientes con NPS radiológicamente indeterminado, efectuando la comprobación diagnóstica por anatomía patológica o seguimiento clínico-radiológico de duración superior a un año. Resultados: Globalmente, la PET-FDG obtuvo una sensibilidad (S) del 92 por ciento, una especificidad (E) del 86,6 por ciento, un valor predictivo positivo (VPP) del 89.4 por ciento, un valor predictivo negativo (VPN) del 89,6 por ciento y una exactitud diagnóstica (ED) del 89 por ciento. Los mejores resultados se obtuvieron para un SUV (Standardized Uptake Value) igual o superior a 2,5, con una S de 92 por ciento, E de 90 por ciento, VPP 92 por ciento, VPN 90 por ciento y ED 91 por ciento. Conclusiones: Podemos caracterizar la mayoría de las lesiones pulmonares indeterminadas mediante la PET-FDG. El uso adicional del SUV posibilita aumentar el valor predictivo positivo y la especificidad de la técnica PET (AU)

[Diagnostic accuracy of semiquantitative analysis of positron emission tomography in radiologically indeterminate lung lesions]. / Exactitud diagnóstica del análisis semicuantitativo de la tomografía por emisión de positrones en lesiones pulmonares radiológicamente indeterminadas.

OBJECTIVE: The objective of this work was to assess the Standardized Uptake Value (SUV) in the differential diagnosis of radiologically indeterminate lung lesions by means of ROC curves. MATERIAL AND METHOD: Forty seven patients were studied by Positron Emission Tomography with 18-fluorine-2-desoxy-D-glucose (FDG PET) analyzing the value of maximum SUV. The patients were classified into three groups. Group 1 = patients without previous neoplasia (WPN) + patients with previous neoplasia (PN). Group 2 = WPN. Group 3 = PN. RESULTS: The ROC curves showed a high diagnostic accuracy in the three groups, with area under the curve (AUC) values of 0.96, 0.98 and 0.91 respectively. The typical error was 0.03, 0.02 and 0.08. The maximum SUV cutoffs with the best diagnostic accuracy for the three groups were: 2.6; 3 and 2.4, with an accuracy (A) of 93.6%, 97% and 92.3%, respectively. Analyzing all the patients globally (group 1), we obtained one false positive result in a patient with hamartoma (max SUV = 2.8) and two false negative results in one patient with lung metastases from malignant fibrohistiocytoma (max SUV = 0.7) and in another patient with lung metastases from unknown origin adenocarcinoma (max SUV = 1.9). CONCLUSIONS: FDG PET permits differentiation with a very high diagnostic accuracy of benign and malignant lung lesions using the maximum SUV. The differences observed between the different groups are due to the different disease prevalence, obtaining a lower negative predictive value of max SUV in patients with previous neoplasia.

Exactitud diagnóstica del análisis semicuantitativo de la tomografía por emisión de positrones en lesiones pulmonares radiológicamente indeterminadas / Semiquantitative analysis of diagnostic accuracy of positron emission tomography in radiologically indeterminated lung lesions

Objetivo: El objetivo de este trabajo ha sido estudiar el valor del 'Standardized Uptake Value' (SUV) en el diagnóstico diferencial de lesiones pulmonares radiológicamente indeterminadas mediante CURVAS ROC. Material y método: Se han estudiado mediante tomografía por emisión de positrones con 18-fluoro-2-desoxi-Dglucosa (PET- FDG) un total de 47 pacientes analizando el valor del SUV máximo. Los enfermos han sido agrupados de la siguiente forma: grupo 1 = pacientes sin antecedentes de neoplasia (PSAN) + pacientes con antecedentes de neoplasia (PCAN); grupo 2 = PSAN; grupo 3 = PCAN. Resultados: En los tres grupos analizados las CURVAS ROC muestran unos valores del Área Bajo la Curva (ABC) para los grupos 1, 2 y 3, de: 0,96, 0,98 y 0,91. Los puntos de corte de mayor exactitud diagnóstica fueron para el grupo 1, 2, y 3 de: 2,6; 3 y 2,4, con una exactitud diagnóstica (ED) del 93,6 per cent, 97 per cent y 92,3 per cent, respectivamente. Analizando globalmente todos los pacientes (grupo 1), sólo hemos obtenido un resultado falso positivo en un paciente con un hamartoma (SUV de 2,8) y dos resultados falsos negativos en dos casos de metástasis pulmonares secundarias a: fibrohistiocitoma maligno (SUV 0,7) y adenocarcinoma de origen desconocido (SUV 1,9). Conclusiones: La FDG-PET permite diferenciar lesiones pulmonares benignas de malignas mediante la obtención del SUV con una elevada exactitud diagnóstica. Las diferencias observadas entre los grupos analizados se atribuyen a la diferente prevalencia de enfermedad, identificándose en los enfermos con antecedentes de neoplasia primaria un menor valor predictivo negativo del SUV (AU)

Early diagnosis of recurrent breast cancer with FDG-PET in patients with progressive elevation of serum tumor markers.

BACKGROUND: The aim of this work is to assess the diagnostic value of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG), in the early detection of tumour recurrence in already treated breast cancer patients in apparent complete remission and with a progressive elevation of tumour markers CEA and/or CA 15.3 without any other clinical or instrumental signs of relapses. METHODS: The author studied 45 women (mean age 58+/-12, range 35-80 years) with histological diagnosis of breast cancer who underwent a tumour marker-guided whole body FDG-PET. All patients were in remission, without any other clinical or instrumental signs of relapses, except for the progressive elevation of CA 15.3 and/or CEA, tested during the follow-up. FDG-PET results were controlled by pathology when histological sampling was possible, by other conventional imaging modalities (US, X-rays, CT, MRI) and/or by clinical follow-up up to 12 months at least. RESULTS: FDG-PET findings were evaluated in 38 patients: 27 resulted positive. Among these 27 PET positive patients 24 were true positive and 3 false positive. Tumour marker guided FDG-PET was also able to discover 3 unknown neoplasms not visualized by other modalities. PET revealed 54 sites of intense focal FDG uptake. The anatomical distribution of these sites was 19 skeleton, 18 lymph node basins, 5 liver, 5 pelvic region, 1 lung, 1 pericardium, 1 pleura, 1 contralateral breast, 2 peritoneum and 1 thyroid bed. Forty-eight of these 54 sites of FDG accumulation were confirmed to be metastases. FDG-PET resulted negative in 11 patients and only in 2 of them the other diagnostic modalities were able to discover metastatic lesions; we had 9 true negative and 2 false positive RESULTS. On the basis of our investigation the performances of tumour marker guided FDG-PET per patient are as follows: sensitivity 92% (24/26), specificity 75% (9/12), positive predictive value 89% (24/27), negative predictive value 82% (9/11), accuracy 87% (33/38). CONCLUSIONS: This study demonstrated the clinical utility of tumour marker-guided PET in the follow-up of breast cancer patients. This diagnostic approach allowed to modify the clinical management in those patients in whom a tumor relapse or unexpected primary neoplasm was discovered.

PET/RMN en paciente con hidrocefalia y metástasis cerebrales tratadas con radiocirugía / PET/RMN in patients with hydrocephalia and brain metastases treated with radiosurgery

Propósito: Las metástasis cerebrales constituyen el tipo más común de tumor cerebral en adultos, causando un incremento de morbilidad y mortalidad en pacientes con cáncer. En la actualidad el tratamiento electivo en la mayoría de los casos es la radiocirugía.• Material y métodos: Presentamos la valoración de la respuesta a la radiocirugía mediante tomografía por emisión de positrones (PET) y resonancia magnética nuclear (RMN) en un paciente con hidrocefalia y metástasis cerebrales (circunstancia excepcional en la práctica asistencial diaria). • Resultados: Ambas exploraciones PET-FDG y RMN identificaron las lesiones metastásicas cerebrales, detectándose mediante PET la afectación multiorgánica del carcinoma de pulmón. La respuesta a la radiocirugía, en este caso la viabilidad tumoral persistente, fue valorada correctamente por PET- FDG. • Conclusiones: Creemos que es necesario una utilización conjunta de la PET y de la RMN como método óptimo y complementarios para estimar con mayor exactitud el grado de respuesta a la radiocirugía en el tratamiento de las metástasis cerebrales. (AU)

Lesión hepática indeterminada por RMN: aportación de la PET-FDG / Undetermined MRI hepatic lesion: contribution of PET-FDG

Propósito: En los pacientes oncológicos, es de extrema importancia descartar un origen secundario de las lesiones hepáticas indeterminadas por Resonancia Magnética Nuclear (RMN) mediante Tomografía por Emisión de Positrones con 18-fluoro-2-desoxi-D-glucosa (PET-FDG). La PET-FDG permite diferenciar con mayor exactitud diagnóstica la etiología de estas lesiones, así como detectar la existencia de recurrencia extrahepática.• Material y métodos: Presentamos el caso clínico de un paciente con antecedentes de melanoma y carcinoma de próstata remitido para valoración por PET-FDG de una lesión hepática indeterminada por RMN e inaccesible a PAAF.• Resultados: La PET-FDG identificó una lesión hepática hipermetabólica sugerente de malignidad, efectuándose una exéresis quirúrgica que confirmó la existencia de metástasis secundaria a melanoma.• Conclusiones: Creemos que la PET-FDG puede aportar una información diagnóstica complementaria de gran valor, colaborando en la re-estadificación de este tipo de pacientes, así como en la definición de una terapia con intención curativa o paliativa de la enfermedad. (AU)

PET- FDG en cáncer oculto primario de mama / Positron emission tomography with fluorine-18-fluorodeoxyglucose in occult primary breast carcinoma

La tomografía por emisión de positrones es una técnica de eficacia comprobada en la detección de la afección locoregional y a distancia del cáncer de mama. Presentamos el caso de dos pacientes con afección axilar secundaria a cáncer oculto de mama, en los que la tomografía por emisión de positrones con 18-fluoro-2-desoxi-D-glucosa (PET-FDG) permitió identificar la localización del tumor primario y por tanto efectuar un tratamiento quirúrgico posterior. Analizamos, además, la utilidad de la PET-FDG y de los métodos de imagen convencionales en el diagnóstico de esta entidad (AU)

[Neuroimaging in epilepsy. Advances in SPECT and PET in epilepsy]. / Neuroimagen en epilepsia. Avances en SPECT y PET en epilepsia.

INTRODUCTION: The incorporation of neuroimaging techniques into the protocol for localization of epileptogenous foci has considerably reduced the need for use of intracranial electrodes. DEVELOPMENT: SPECT and PET are most useful in cases of epilepsy with no cerebral morphological anomalies, in which there are therefore no changes which shown on MR. Cerebral SPECT with perfused tracers, such as 99mTc-HMPAO, 123I-MP or 99mTc-ECD, permit the study of patients during interictal and perictal phases. In the latter case, although the procedure is complex, one may observe an increase in cerebral blood flow in the epileptogenous focus in 90% of the patients. PET with FDG allows interictal study of patients, and shows reduced metabolism in the epileptogenic region. By comparison with video-EEG there are S = 84% and SP = 86% in temporal lobe epilepsy. The diagnostic efficiency of these two techniques is rather less in the localization of extratemporal foci and in multifocal epilepsies, although it is always better than with other diagnostic techniques. They have also been shown to be useful in the prognosis of functional recovery after surgery. CONCLUSION: The possibility of studying neuroreceptors may be of great use in the investigation of the etiopathogenesis of epilepsy, and thus lead to improvement in the clinical and therapeutic management of patients. With SPECT, 123I-Iomacenil and 123I-lododexetimide are used. With PET and 11C-Carfentanyl opiate receptors have been studied. With 11C-Fluomacenil one may study the cerebral distribution of the benzodiazepine receptors.

Avances en SPECT y PET en epilepsia / Advances in spect and pet in epilepsy

Introducción. La incorporación de las técnicas de neuroimagen al protocolo de localización de los focos epileptógenos ha disminuido de forma considerable la necesidad de utilizar electrodos intracraneales. Desarrollo. La SPECT y PET alcanzan su máxima utilidad en aquellos casos en que las epilepsias no cursan con anomalías morfológicas cerebrales y que, por tanto, no son visibles con RM. La SPECT cerebral con trazadores de perfusión, como 99m Tc-HMPAO, 123 I-IMP o 99m Tc-ECD, permite estudiar a los pacientes en fase interictal y perictal; en este último caso, aunque la metodología es complicada, se puede observar aumento de flujo sanguíneo cerebral en el foco epileptógeno en un 90 por ciento de los pacientes. La PET con FDG permite el estudio interictal de los pacientes, demostrando disminución del metabolismo en la región epileptógena. En comparación con el vídeo-EEG presenta una S= 84 por ciento yE= 86 por ciento en las epilepsias del lóbulo temporal. El rendimiento diagnóstico de ambas técnicas es algo menor en la localización de focos extratemporales y de epilepsias multifocales, aunque siempre mayorque con otras técnicas diagnósticas. También han demostrado tener valor pronóstico en el examen de la recuperación funcional tras la cirugía. Conclusiones. La posibilidad de estudiar neurorreceptorespuede ser de gran utilidad en la investigación de la etiopatogenia de la epilepsia, condicionando así un mejor manejo clínico y terapéutico de los pacientes. Con la SPECT se utiliza el 123 I-Iomacenil y la123 I-Iododexetimida.Con la PET y el 11C-Carfentanilse han estudiado los receptores opiáceos. Con el 11C-Fluomacenil puede estudiarse la distribución cerebral de los receptores benzodiacepínicos (AU)

[PET-FDG in thyroid cancer with high thyroglobulin levels and negative 131-I scan. A case report]. / La PET-FDG en el cáncer de tiroides ante niveles altos de tiroglobulina y rastro 131-I negativo. A Propósito de un caso.

The value of whole body PET-FDG in the evaluation of metastases has been demonstrated in a wide variety of tumors. In this report, we present the case of a patient with antecedent of papillary thyroid carcinoma, who was operated twelve years ago, and submitted to an ablative dose of residual thyroid tissue through 131I, being the levels of thyroglobulin normals. After twelve years of evolution, the patient refers bag pain and respiratory trouble, appearing in the CT image suspicious of metastases in right pulmonary base. The levels of thyroglobulin were shown increased, being the 131I scan negative. A whole body PET-FDG study was performed in order to exclude metastases of his malignant process, showed multiple high FDG uptake focus in brain, cerebellum, neck, chest, lymphatic nodes and bone, suggestive of dedifferentiated disease These findings were confirmed subsequently in the clinic evolution. Therefore, whole-body PET-FDG is a complementary diagnostic technique for study patients with CDT (Thyroid Differentiated Carcinoma) with 131I scan negative and rising thyroglobulin levels.

[The role of PET-FDG in questionable diagnosis of relapse in the presence of radionecrosis of brain tumors]. / Papel de la PET-FDG ante la duda diagnóstica de recidiva frente a radionecrosis en tumores cerebrales.

INTRODUCTION: Although CT and MR are sensitive techniques for the detection of cerebral tumours, both have limitations in distinguishing between tumour relapse (TR) and post-treatment radionecrosis (RN). PATIENTS AND METHODS: In this study we have determined the usefulness of metabolic imaging with PET-FDG in such situations. We assessed 70 patients with CNS tumours (22 low grade astrocytomas, 25 high grade astrocytomas, 3 oligodendrogliomas, 13 metastatic tumours and 7 other tumours. All had been treated with radiotherapy and other treatments such as radiosurgery, chemotherapy or different types of surgery, and presented clinical pictures which made it necessary to decide the differential diagnosis of relapse or radionecrosis. RESULTS: In the PET-FDG study visual and semiquantitative analysis was done by SUV (Standardized Update Value). Confirmation of the findings was obtained in 44 cases (24 TR and 20 RN). MR was doubtful or inconclusive in most cases, whilst with PET correct diagnosis was made in all cases. CONCLUSIONS: Metabolic imaging with PET-FGD is better than anatomostructural imaging techniques for differential diagnosis between tumour relapse and radionecrosis in CNS tumours which have been treated. Prospective studies are necessary for evaluation of SUV as a factor for prognosis of survival.

Technetium-99m tetrofosmin rest/stress myocardial SPET with a same-day 2-hour protocol: comparison with coronary angiography. A Spanish-Portuguese multicentre clinical trial.

Technetium-99m tetrofosmin (Myoview) has unique properties for myocardial perfusion imaging very early after injection of the tracer. We used a very short same-day rest/stress protocol, to be performed within 2 h and evaluated its diagnostic accuracy. The study included 144 patients from seven Spanish and four Portuguese centres with a diagnosis of uncomplicated coronary artery disease (CAD); 78 patients (54%) had no history of prior myocardial infarction. Patients were injected with /=50%) was achieved with a sensitivity of 64% for the left anterior descending artery, 49% for the left circumflex artery and 86% for the right coronary artery, and an accuracy of 71%, 72% and 73% respectively. Concordance of SPET and CA was 62% for single-vessel disease and 68% for multivessel disease. In conclusion, this Spanish-Portuguese multicentre clinical trial confirmed, in a considerable number of patients who underwent coronary angiography, the feasibility of 99mTc tetrofosmin (Myoview) rest/stress myocardial SPET using a very short protocol (2 h).

Drug therapy and cerebral perfusion in obsessive-compulsive disorder.

Cerebral perfusion in a previously untreated patient with obsessive-compulsive disorder was studied qualitatively and semi-quantitatively with SPECT before, and during and 6 wk after treatment with clomipramine. The patient's symptoms disappeared while on medication and relapsed after drug withdrawal. At baseline, there was an increased perfusion ratio in the bilateral orbitofrontal, anterior cingular, frontotemporal and right caudate regions. These alterations disappeared during drug therapy. After treatment discontinuation and symptomatic relapse, the same pattern of hyperactivity was found. Semiquantitative measurements after treatment withdrawal showed a return to perfusion values similar to those observed before treatment in subcortical structures. In cortical areas, this level was not completely achieved. Subtraction SPECT images showed perfusion changes at the orbitofrontal, caudate and thalamic levels.

[The usefulness of 99mTc-tetrofosmin in the diagnosis of pulmonary tumors. A preliminary assessment]. / Utilidad del 99mTc-tetrofosmin en el diagnóstico de tumoraciones pulmonares. Valoración preliminar.

We conducted a preliminary study of captation of the new radiopharmaceutical 99mTc-tetrofosmin in cases of primary carcinoma of the lung, analyzing the results of 5 cases studied before surgery with single photon emission tomography (SPECT) of the lung. The results obtained by imaging were compared with those from surgery. Tumor size ranged between 3.5 and 9 cm. In all cases the images showed that captation of the radiotracer by the neoplasm was satisfactory, leaving the area of the tumor clearly distinguishable from normal adjacent lung tissue and giving no signs of interference caused by absorption of 99mTc-tetrofosmin by contiguous structures (heart or liver). Based on these preliminary results we assert that SPECT of the lung using 99mTc-tetrofosmin may be useful in the clinical diagnosis of malignant lung tumors, although further research must determine to what extent the technique can be relied upon.

Cerebral perfusion, electrical activity and effects of serotonergic treatment in obsessive-compulsive disorder. A preliminary study.

An abnormally increased glucose metabolism has been described with positron emission tomography (PET) in frontal and caudate regions of obsessive-compulsive patients. Perfusion and electroencephalographic studies have been less conclusive. However, these techniques are, currently, more available than PET and, therefore, deserve further study because of their possible clinical applications. In this article, 13 obsessive-compulsive patients were studied with quantitative EEG and auditory and visual evoked potentials. Six of them were studied also with perfusion single photon emission tomography. A group of 4 patients was studied with both techniques before and after a serotonergic treatment. Increased global, beta, and theta electrical power together with an increased perfusion in frontal regions was observed. The patients also showed a delta power increase over right temporal and frontal regions, together with increased perfusion in the right basal ganglia region as well as a decreased amplitude of the P50 and N100 waves of the auditory evoked potentials over temporal electrodes; these alterations were reduced with treatment. These results are discussed in the context of current data about serotonergic neurotransmission.