Rendimiento de la PET/TC con 11C-colina en el seguimiento del cáncer de próstata / Effectiveness of 11C-choline PET/CT in prostate cancer surveillance

Objetivo Analizar el rendimiento diagnóstico de la PET/TC con 11C-colina en el seguimiento del cáncer de próstata (CaP), especialmente en pacientes con antígeno prostático específico (PSA)>1ng/ml. Material y métodos Se evaluaron retrospectivamente 329 exploraciones PET/TC con 11C-colina de 191 pacientes (68,2±7,2 años) con CaP con recaída bioquímica o en seguimiento (PSA en el momento de la PET/TC: 13,0±84,2ng/ml). El tratamiento inicial fue prostatectomía radical en 81 pacientes y otros tratamientos (radioterapia, quimioterapia, hormonoterapia) en 110. La PET/TC se adquirió 20min después de la inyección de 555-740MBq de 11C-colina. El seguimiento mínimo fue superior a 12 meses. Resultados Doscientas diecinueve (66,6%) de las 329 exploraciones PET/TC fueron positivas. El porcentaje de positivos fue significativamente mayor en los pacientes con otro tratamiento inicial diferente a la prostatectomía radical (85,6 frente a 43,6%, respectivamente). Ciento treinta PET/TC (59,4%) mostraron recidiva local, 48 (21,9%) a distancia y 41 (18,7%) local más a distancia. El abordaje terapéutico inicial se modificó en 139 casos (63,5%). De las 81 PET/TC con 11C-colina realizadas con PSA<1ng/ml, 23 (28,4%) fueron positivas. El abordaje terapéutico inicial se modificó en 9 (11,1%). Tres de 63 pacientes (4,8%) fallecieron por CaP. Conclusiones La PET/TC con 11C-colina demostró su eficacia en el seguimiento y la reestadificación del CaP, incluso en pacientes con PSA sérico<1ng/ml. El rendimiento diagnóstico fue diferente según el tratamiento inicial al que fueron sometidos los pacientes, siendo mayor en aquellos tratados inicialmente con otros tratamientos distintos de la PR prostatectomía radical (AU)

Aim Our aim was to analyse the performance of 11C-choline PET/CT in prostate cancer (PCa) surveillance, especially in patients with prostate specific antigen (PSA)<1ng/ml. Material and methods Three hundred and twenty-nine 11C-choline PET/CT examinations from 191 patients (68.2±7.2 years) submitted for PCa surveillance or biochemical recurrence were retrospectively evaluated (PSA at study was 13.0±84.2ng/ml). Main initial treatment was radical prostatectomy in 81 patients, and other treatments (radiotherapy, chemotherapy, hormonotherapy) in 110. PET/CT was acquired 20min after injection of 555-740MBq of 11C-choline. Minimum follow-up was 12 months. Results Two hundred and nineteen (66.6%) out of the 329 PET/CT examinations were positive. The percentage of positive examinations was significantly higher in patients with other initial treatment than radical prostatectomy compared to patients with radical prostatectomy (85.6 vs. 43.6%, respectively). One hundred and thirty PET/CT (59.4%) showed local recurrence, 48 (21.9%) distant recurrence, and 41 (18.7%) local plus distant recurrence. Initial therapeutic approach was changed in 139 cases (63.5%). In the subgroup of 81 11C-choline PET/CT scans performed with PSA<1ng/ml, 23 (28.4%) showed a positive result. Initial therapeutic approach was changed in 9 (11.1%). Three (4.8%) out of 63 patients died as per PCa. Conclusions 11C-choline PET/CT demonstrated its effectiveness in PCa surveillance and restaging, even in patients with serum PSA<1ng/ml. The diagnostic performance was different depending on the initial treatment, been higher in patients with non-surgical treatment (AU)

Effectiveness of 11C-choline PET/CT in prostate cancer surveillance.

AIM: Our aim was to analyse the performance of [11C]choline PET/CT in prostate cancer (PCa) surveillance, especially in patients with prostate specific antigen (PSA) < 1 ng/mL. MATERIAL AND METHODS: Three hundred and twenty-nine [11C]choline PET/CT examinations from 191 patients (68.2 ±â€¯7.2 years) submitted for PCa surveillance or biochemical recurrence were retrospectively evaluated. PSA at study was 13.0 ±â€¯84.2 ng/mL. Main initial treatment was radical prostatectomy (RP) in 81 patients, and other treatments (radiotherapy, chemotherapy, hormonotherapy) in 110. PET/CT was acquired 20' after injection of 555-740 MBq of [11C]choline. Minimum follow-up was 12 months. RESULTS: Two hundred and nineteen (66.6%) out of the 329 PET/CT examinations were positive. The percentage of positive examinations was significantly higher in patients with other initial treatment than RP compared to patients with RP (85.6% vs. 43.6%, respectively). One hundred and thirty PET/CT (59.4%) showed local recurrence, 48 (21.9%) distant recurrence, and 41 (18.7%) local plus distant recurrence. Initial therapeutic approach was changed in 139 cases (63.5%). In the subgroup of 81 [11C]choline PET/CT scans performed with PSA < 1 ng/mL, 23 (28.4%) showed a positive result. Initial therapeutic approach was changed in 9 (11.1%). Three (4.8%) out of 63 patients died as per PCa. CONCLUSION: [11C]choline PET/CT demonstrated its effectiveness in PCa surveillance and restaging, even in patients with serum PSA < 1 ng/mL. The diagnostic performance was different depending on the initial treatment, been higher in patients with non-surgical treatment.

18F-FDG PET/CT in cardiovascular infection and inflammation.

The diagnosis of cardiovascular infection and inflammation by [18F]FDG PET/CT in Nuclear Cardiology is of growing interest, because with respect to echocardiography this technique has improved the certainty in the diagnosis of infective endocarditis in patients with prosthetic valves, the increasing number of patients with implantable cardiac devices because of the progressive ageing of the population, as well as in patients with suspected large vessel vasculitis. All are serious clinical situations which require correct diagnosis and appropriate treatment as soon as possible, because they can cause severe complications, high mortality and also increased health care costs. We review the use of [18F]FDG PET/CT in cardiovascular infection and inflammation, including the clinical point of view and the contribution of other image modalities. We focus on the appropriate methodology for this exploration, patient preparation, image acquisition and correct interpretation and the quantification possibilities, defining the specific characteristics of the diagnosis in patients with prosthetic valves, implantable cardiac devices and large vessel vasculitis in the initial diagnosis as well as during follow-up to assess treatment response. We analyze the possible causes of false positive and false negative results and emphasize the special value of a multidisciplinary team for optimal management of these patients.

Preparación, radiomarcaje con 99mTc y 67Ga y estudios de biodistribución de nanopartículas de albúmina con recubrimientos poliméricos / Preparation, radiolabeling with 99mTc and 67Ga and biodistribution studies of albumin nanoparticles covered with polymers

OBJETIVO: Optimizar el radiomarcaje con 99mTc y 67Ga de nanopartículas de albúmina recubiertas con 4 polímeros sintéticos distintos y evaluar su estabilidad in vivo e in vitro, así como su biodistribución in vivo tras su administración intravenosa. MATERIAL Y MÉTODOS: Las nanopartículas se prepararon empleando albúmina y albúmina modificada con NOTA mediante el método de desolvatación y se recubrieron con 4 polímeros distintos; HPMC, GMN2, GPM2 y GTM2. Se purificaron, liofilizaron y caracterizaron. El marcaje con 99mTc se realizó con 74MBq de pertecnetato [99mTc] sódico previamente reducido con una disolución ácida de cloruro de estaño a diferentes concentraciones (0,003; 0,005; 0,007; 0,01; 0,05 y 0,1mg/ml), a distintos tiempos (5, 10, 15, 30 y 60min) y temperaturas (temperatura ambiente, 40°C y 60°C). El marcaje con 67Ga se llevó a cabo mediante incubación de las nanopartículas con 37MBq de cloruro de 67Ga (obtenido a partir de citrato de 67Ga comercial) a distintos tiempos (10 y 30min) y temperaturas (temperatura ambiente, 30°C y 60°C) y posterior purificación con microconcentradores. La pureza radioquímica de ambos marcajes se evaluó mediante TLC. Se llevaron a cabo estudios de estabilidad de las nanopartículas marcadas en suero fisiológico y plasma sanguíneo. Los estudios de biodistribución de las nanopartículas recubiertas con el polímero GPM2 se llevaron a cabo en ratas Wistar tras la administración intravenosa de las nanopartículas. Se realizaron animales control con pertecnetato [99mTc] sódico y cloruro de 67Ga. Posteriormente, los animales fueron sacrificados y se midió la actividad de los órganos en un contador gamma. RESULTADOS: El marcaje con 99mTc se llevó a cabo de forma óptima con una concentración de estaño de 0,007mg/ml para las nanopartículas GPM2 y de 0,005mg/ml para el resto de formulaciones, con un tiempo de marcaje de 10min y a temperatura ambiente. En el caso del 67Ga el marcaje se optimizó a 30°C de temperatura y 30min de incubación. En ambos casos, la pureza radioquímica obtenida fue superior al 97%. Las nanopartículas presentaron una elevada estabilidad in vitro pasadas las 48h del marcaje (70% las nanopartículas marcadas con 99mTc y 90% las marcadas con 67Ga). Los estudios de biodistribución de las nanopartículas [99mTc]-GPM2 y [67Ga]-NOTA-GPM2 mostraron una elevada acumulación de actividad en el hígado tanto a las 2h como a las 24h de la administración intravenosa. CONCLUSIÓN: El procedimiento de marcaje con 99mTc y 67Ga de nanopartículas de albúmina y albúmina modificada con NOTA permite la obtención de nanopartículas con elevados rendimientos de marcaje y una adecuada estabilidad in vitro, permitiendo su utilización para la realización de estudios in vivo

OBJECTIVE: To optimize radiolabeling with 99mTc and 67Ga of albumin nanoparticles coated with 4 differents synthetic polymers and to evaluate their stability in vivo and in vitro, as well as their biodistribution in vivo after intravenous administration. MATERIAL AND METHODS: The nanoparticles were prepared using albumin and NOTA-modified albumin by the desolvation method and coated with 4 different polymers; HPMC, GMN2, GPM2 and GTM2. They were purified, lyophilized and characterized. Radiolabelling with 99mTc was perfomed with 74 MBq of 99mTc sodium pertechnetate, previously reduced with and acid solution of tin chloride at different concentrations (0.003, 0.005, 0.007, 0.01, 0.05 and 0.1mg/ml) and at different times (5, 10, 15, 30 and 60minutes) and temperatures (room temperature, 40°C and 60°C). Radiolabelling with 67Ga was perfomed by incubation of the nanoparticles with 37 MBq of 67Gallium chloride (obtained from commercial gallium-67 citrate) at different times (10 and 30minutes) and temperatures (room temperature, 30°C and 60°C), and posterior purification with microconcentrators. The radiochemical purity was evaluated by TLC. Stability studies of radiolabeled nanoparticles in physiological serum and blood plasma were perfomed. Biodistribution studies of nanoparticles coated with GPM2 polymer were carried out in Wistar rats after intravenous administration of the nanoparticles. Control animals were carried out with 99mTc sodium pertechnetate and 67Ga chloride. To do so, the animals were killed and activity in organs was measured in a gamma counter. RESULTS: 99mTc labeling was carried out optimally with a tin concentration of 0.007mg/ ml for the GPM2 nanoparticles and 0.005mg / ml for the rest of the formulations, with a radiolabelling time of 10minutes at room temperature. In the case of 67Ga the label was optimized at 30° C temperature and 30minutes of incubation. In both cases the radiochemical purity obtained was greater than 97%. The nanoparticles showed high stability in vitro after 48hours of labeling (70% nanoparticles labeled with 99mTc and 90% those labeled with 67Ga). Biodistribution studies of nanoparticles 99mTc -GPM2 and 67Ga -NOTA-GPM2 showed a high accumulation of activity in the liver at 2 and 24hours after intravenous administration. CONCLUSION: The labeling procedure with 99mTc and 67Ga of albumin and albumin modified with NOTA nanoparticles allows obtaining nanoparticles with high labeling yields and adequate in vitro stability, allowing their use for in vivo studies

Detección de meningioma en un paciente con deterioro cognitivo leve evaluado mediante 11C-PIB y 18F-FDG PET/TC / Detection of meningioma in a patient with mild cognitive impairment assessed by 11C-PIB and 18F-FDG PET/CT

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Preparation, radiolabeling with 99mTc and 67Ga and biodistribution studies of albumin nanoparticles covered with polymers. / Preparación, radiomarcaje con 99mTc y 67Ga y estudios de biodistribución de nanopartículas de albúmina con recubrimientos poliméricos.

OBJECTIVE: To optimize radiolabeling with 99mTc and 67Ga of albumin nanoparticles coated with 4 differents synthetic polymers and to evaluate their stability in vivo and in vitro, as well as their biodistribution in vivo after intravenous administration. MATERIAL AND METHODS: The nanoparticles were prepared using albumin and NOTA-modified albumin by the desolvation method and coated with 4 different polymers; HPMC, GMN2, GPM2 and GTM2. They were purified, lyophilized and characterized. Radiolabelling with 99mTc was perfomed with 74 MBq of 99mTc sodium pertechnetate, previously reduced with and acid solution of tin chloride at different concentrations (0.003, 0.005, 0.007, 0.01, 0.05 and 0.1mg/ml) and at different times (5, 10, 15, 30 and 60minutes) and temperatures (room temperature, 40°C and 60°C). Radiolabelling with 67Ga was perfomed by incubation of the nanoparticles with 37 MBq of 67Gallium chloride (obtained from commercial gallium-67 citrate) at different times (10 and 30minutes) and temperatures (room temperature, 30°C and 60°C), and posterior purification with microconcentrators. The radiochemical purity was evaluated by TLC. Stability studies of radiolabeled nanoparticles in physiological serum and blood plasma were perfomed. Biodistribution studies of nanoparticles coated with GPM2 polymer were carried out in Wistar rats after intravenous administration of the nanoparticles. Control animals were carried out with 99mTc sodium pertechnetate and 67Ga chloride. To do so, the animals were killed and activity in organs was measured in a gamma counter. RESULTS: 99mTc labeling was carried out optimally with a tin concentration of 0.007mg/ ml for the GPM2 nanoparticles and 0.005mg / ml for the rest of the formulations, with a radiolabelling time of 10minutes at room temperature. In the case of 67Ga the label was optimized at 30° C temperature and 30minutes of incubation. In both cases the radiochemical purity obtained was greater than 97%. The nanoparticles showed high stability in vitro after 48hours of labeling (70% nanoparticles labeled with 99mTc and 90% those labeled with 67Ga). Biodistribution studies of nanoparticles 99mTc -GPM2 and 67Ga -NOTA-GPM2 showed a high accumulation of activity in the liver at 2 and 24hours after intravenous administration. CONCLUSION: The labeling procedure with 99mTc and 67Ga of albumin and albumin modified with NOTA nanoparticles allows obtaining nanoparticles with high labeling yields and adequate in vitro stability, allowing their use for in vivo studies.

Inesperada metástasis mamaria de melanoma cutáneo en PET/TC con 18F-FDG / Unexpected breast metastasis from cutaneous melanoma on 18F-FDG PET/CT

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Aportación de la PET/TC con 11C-colina en la recidiva bioquímica del cáncer de próstata con antígeno específico prostático sérico inferior a 1 ng/ml / Contribution of 11C-Choline PET/CT in prostate carcinoma biochemical relapse with serum PSA level below 1 ng/ml

Objetivo. La PET/TC con 11C-colina ha mostrado buenos resultados en la reestadificación del cáncer de próstata (CP) con antígeno específico prostático (PSA) elevado. Su uso con niveles bajos es controvertido. Nuestro objetivo fue evaluar la aportación de la 11C-colina PET/TC en pacientes con CP, recidiva bioquímica y PSA <1ng/ml. Material y método. Se evaluaron retrospectivamente 50 pacientes consecutivos (edad: 65,9±5,6 años) con recidiva bioquímica de CP y PSA <1ng/ml (media: 0,4±0,2). La PET/TC fue adquirida a los 20 min de la administración intravenosa de 555-740 MBq de 11C-colina. El seguimiento mínimo fue de 30 meses. Resultados. De los 50 pacientes, 21 (42%) mostraron una 11C-colina PET/TC anormal. En 7 (14%) se confirmó la afectación tumoral (4 en lecho prostático, 4 en ganglios pélvicos, 2 en ganglios mediastínicos y un tumor síncrono sigmoide) y se modificó en todos ellos el tratamiento inicialmente previsto. En 2 pacientes (4%) se confirmó enfermedad benigna (uno con sarcoidosis, otro con secuelas de TBC) y en 3 pacientes (6%) ausencia de enfermedad. En los otros 9 pacientes (18%) los hallazgos no fueron estudiados (7 en ganglios mediastínicos y 4 en pélvicos). La 11C-colina PET/TC fue normal en 29 pacientes (58%). Solo en 2 de ellos se confirmó recidiva a los 30 meses. Conclusión. La 11C-colina PET/TC demostró su utilidad en la recidiva bioquímica de CP y PSA <1 ng/ml en el 14% de los pacientes al mostrar enfermedad tumoral, lo que tuvo implicaciones terapéuticas. En un 4% se detectó enfermedad benigna. Una 11C-colina PET/TC normal se asoció a una tasa de recurrencia muy baja a los 30 meses

Objective. 11C-choline PET/CT has demonstrated good results in the restaging of prostate cancer (PCa) with high serum prostate specific antigen (PSA), but its use in patients with low serum PSA is controversial. Our aim was to evaluate the contribution of 11C-choline PET/CT in patients with PCa, biochemical relapse and PSA <1 ng/ml. Material and method. Fifty consecutive patients (mean age: 65.9±5.6 years) with biochemical relapse of PCa and serum PSA <1ng/ml were evaluated retrospectively. PET/CT was performed 20min after intravenous administration of 555-740 MBq of 11C-choline. Minimum follow up time was 30 months. Results. Twenty-one out of 50 patients (42%) had an abnormal 11C-choline PET/CT. In 7 out of 21 patients (14%) tumor was confirmed (4 in prostatic bed, 4 in pelvic lymph nodes, 2 in mediastinal lymph nodes and one synchronous sigmoid carcinoma), and in all cases the initial therapeutic planning was modified. In 2 patients (4%) subsequent tests diagnosed a benign disease (one sarcoidosis, one tuberculosis sequelae) and in 3 patients (6%) they ruled out pathology. The other 9 patients (18%) had no further assessment (7 mediastinal and 4 pelvic lymph nodes). Twenty-nine out of 50 patients (58%) had a normal PET/CT. At 30 months, follow up recurrence was confirmed only in 2 of these patients. Conclusions. 11C-choline PET/CT proved its usefulness in demonstrating tumor in 14% of patients with BR of PCa and serum PSA <1ng/ml, with therapeutic implications. In 4% of patients a benign condition was detected. A normal 11C-choline PET/CT was associated with a very low rate of recurrence at 30 months

Imagen de PET/TC con 18F-FDG en "casco de minero" de una metástasis solitaria del hueso frontal secundaria a adenocarcinoma rectal / "Miner's cap-like" solitary frontal bone metastasis from rectal adenocarcinoma on 18F-FDG PET/CT

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Patrones de retención de 11C-PIB en la sustancia blanca y en la sustancia gris cerebral de pacientes con hidrocefalia a presión normal idiopática. Un análisis visual / 11C-PIB retention patterns in white and grey cerebral matter in idiopathic normal pressure hydrocephalus patients. A visual analysis

Objetivo. El depósito cortical de amiloide, una seña de identidad de la enfermedad de Alzheimer, se ha observado en la hidrocefalia a presión normal (HPN). Nuestro objetivo fue comparar el patrón de retención de 11C-PIB PET/TC en pacientes con HPN y sujetos sanos. Material y métodos. Hemos comparado el patrón de retención de 11C-PIB en 13 casos de HPN seleccionados para cirugía derivativa con una población control normal. Las imágenes se analizaron visualmente y puntuaron de 1-4 (de ligera a muy alta retención de PIB) tanto en la sustancia gris como en la sustancia blanca (SB). La puntuación se analizó por separado en las regiones infra y supratentoriales de ambos grupos. Se emitió un informe clínico en términos de positivo, negativo o dudoso/equívoco. Resultados. Ocho 11C-PIB PET/TC se informaron como negativos, 3 positivos y 2 dudosos. Cinco de 13 pacientes mostraron al menos una región cortical con retención de PIB de intensidad mayor que la observada en el grupo control. En general, la retención de PIB en la SB de los pacientes con HPN tuvo puntuaciones menores que en el grupo control, mostrando una diferencia estadísticamente significativa en la SB infratentorial (92/104 vs. 54/56, p<0,05) y una tendencia a ser menor en las regiones supratentoriales (70/84 vs. 122/156; p=0,327), en particular en la región periventricular superior (25/28 vs. 40/52; p=0,134). Conclusiones. Los patrones de retención de 11C-PIB parecen ser diferentes en los pacientes con HPN comparados con sujetos normales. La retención de PIB en la SB de la HPN aparece menos intensa que en sujetos sanos y estos muestran un mayor grado de retención de PIB en las regiones corticales. Esto merece ser tomado en consideración (AU)

Objective. Cortical cerebral amyloid disease, a hallmark of Alzheimer's disease, has also been observed in idiopathic normal pressure hydrocephalus (iNPH). The aim of this study was to compare the 11C-PIB PET/CT retention pattern in iNPH patients and healthy subjects. Material and methods. A comparison was made of the 11C-PIB PET/CT retention pattern in 13 iNPH patients selected for surgical deviation, compared to a normal control population. Images were visually analyzed and scored for gray matter and white matter (WM) from 1 to 4 (slight to very high PIB retention). The scoring was analyzed in both groups separately for infra- and supra-tentorial regions. A comprehensive clinical report was presented in terms of positive, negative, or equivocal. Results. 11C-PIB PET/CT scan were reported as negative in 8, positive in 3, and equivocal in 2. Five of 13 patients showed at least one cortical area with PIB retention with an intensity higher than that observed in the control group. Overall, white matter (WM) PIB retention of iNPH scored lower than in the control group, showing a statistically significant difference in the infratentorial WM (92/104 vs 54/56; p<.05) and a tendency to be lower in the supratentorial regions (70/84 vs 122/156, p=.327), in particular in the upper periventricular region (25/28 vs 40/52; p=.134). Conclusions. The PIB retention pattern seems to be different in NPH, compared to normal subjects. PIB retention in WM of NPH appears less intense than in healthy subjects, and they show a higher degree of PIB retention in cortical regions. This deserves to be taken it into account (AU)

11C-PIB retention patterns in white and grey cerebral matter in idiopathic normal pressure hydrocephalus patients. A visual analysis. / Patrones de retención de 11C-PIB en la sustancia blanca y en la sustancia gris cerebral de pacientes con hidrocefalia a presión normal idiopática. Un análisis visual.

OBJECTIVE: Cortical cerebral amyloid disease, a hallmark of Alzheimer's disease, has also been observed in idiopathic normal pressure hydrocephalus (iNPH). The aim of this study was to compare the 11C-PIB PET/CT retention pattern in iNPH patients and healthy subjects. MATERIAL AND METHODS: A comparison was made of the 11C-PIB PET/CT retention pattern in 13 iNPH patients selected for surgical deviation, compared to a normal control population. Images were visually analyzed and scored for gray matter and white matter (WM) from 1 to 4 (slight to very high PIB retention). The scoring was analyzed in both groups separately for infra- and supra-tentorial regions. A comprehensive clinical report was presented in terms of positive, negative, or equivocal. RESULTS: 11C-PIB PET/CT scan were reported as negative in 8, positive in 3, and equivocal in 2. Five of 13 patients showed at least one cortical area with PIB retention with an intensity higher than that observed in the control group. Overall, white matter (WM) PIB retention of iNPH scored lower than in the control group, showing a statistically significant difference in the infratentorial WM (92/104 vs 54/56; p<.05) and a tendency to be lower in the supratentorial regions (70/84 vs 122/156, p=.327), in particular in the upper periventricular region (25/28 vs 40/52; p=.134). CONCLUSIONS: The PIB retention pattern seems to be different in NPH, compared to normal subjects. PIB retention in WM of NPH appears less intense than in healthy subjects, and they show a higher degree of PIB retention in cortical regions. This deserves to be taken it into account.

Contribution of 11C-Choline PET/CT in prostate carcinoma biochemical relapse with serum PSA level below 1 ng/ml. / Aportación de la PET/TC con 11C-colina en la recidiva bioquímica del cáncer de próstata con antígeno específico prostático sérico inferior a 1 ng/ml.

OBJECTIVE: 11C-choline PET/CT has demonstrated good results in the restaging of prostate cancer (PCa) with high serum prostate specific antigen (PSA), but its use in patients with low serum PSA is controversial. Our aim was to evaluate the contribution of 11C-choline PET/CT in patients with PCa, biochemical relapse and PSA <1 ng/ml. MATERIAL AND METHOD: Fifty consecutive patients (mean age: 65.9±5.6 years) with biochemical relapse of PCa and serum PSA <1ng/ml were evaluated retrospectively. PET/CT was performed 20min after intravenous administration of 555-740 MBq of 11C-choline. Minimum follow up time was 30 months. RESULTS: Twenty-one out of 50 patients (42%) had an abnormal 11C-choline PET/CT. In 7 out of 21 patients (14%) tumor was confirmed (4 in prostatic bed, 4 in pelvic lymph nodes, 2 in mediastinal lymph nodes and one synchronous sigmoid carcinoma), and in all cases the initial therapeutic planning was modified. In 2 patients (4%) subsequent tests diagnosed a benign disease (one sarcoidosis, one tuberculosis sequelae) and in 3 patients (6%) they ruled out pathology. The other 9 patients (18%) had no further assessment (7 mediastinal and 4 pelvic lymph nodes). Twenty-nine out of 50 patients (58%) had a normal PET/CT. At 30 months, follow up recurrence was confirmed only in 2 of these patients. CONCLUSIONS: 11C-choline PET/CT proved its usefulness in demonstrating tumor in 14% of patients with BR of PCa and serum PSA <1ng/ml, with therapeutic implications. In 4% of patients a benign condition was detected. A normal 11C-choline PET/CT was associated with a very low rate of recurrence at 30 months.

Candida Esophagitis Incidentally Detected by 18F-FDG PET/CT in Metastatic Lung Adenocarcinoma.

The diagnostic significance of esophageal 18F-FDG uptake in oncologic patient is challenging. It may represent normal physiological uptake, inflammation, infection, or neoplasia. We present a patient with a recent diagnosis of non-small cell lung cancer stage IV and esophageal mild uptake on 18F-FDG PET/CT scan. Biopsy of esophageal mucosa demonstrated Candida esophagitis.