Wet chemical synthesis of TGA capped Ag2S nanoparticles and their use for fluorescence imaging and temperature sensing in living cells.

In this work, we describe a simple wet chemical route for preparing silver sulfide nanoparticles (Ag2S) encapsulated with thioglycolic acid (TGA). By using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDS) microanalysis, transmission electron microscopy (TEM), and dynamic light scattering (DLS), we have found that these nanoparticles were enrobed by TGA molecules and they have an Ag/S ratio nearly equal to 2.2 and a nearly spherical shape with two average size populations. Photoluminescence (PL) spectroscopy has shown that these nanoparticles are highly luminescent, photostable and photobleaching resistant and they emit in the first biologic window with a band peaking in the NIR region at 915 nm. We have demonstrated through a 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay protocol and using U-87 MG human living cells that these nanoparticles are biocompatible with a viability ratio higher than 80% for a concentration equal to 100 µg mL-1. By investigating the effect of pH, ionic strength and thermal quenching on the PL emission, we have shown that these nanoparticles provide a convenient stable tool to measure temperature in the biological range with a relative thermal sensitivity higher than 5% per °C and they may be used as suitable fluorescent probes for living cell imaging and intracellular temperature mapping.

[Evaluation of efficacy and clinical impact of 18F-FDG-PET in the diagnosis of recurrent medullary thyroid cancer with increased calcitonin and negative imaging test]. / Evaluación de la eficacia y del impacto clínico de la PET-18F-FDG en el diagnóstico de recurrencia del carcinoma medular de tiroides con calcitonina elevada y pruebas de imagen negativas.

AIM: To evaluate the efficacy and clinical impact of the FDG-PET in the diagnosis of suspicion of recurrence of medullary thyroid cancer (MTC) in patients with elevated serum calcitonin and negative imaging test. MATERIAL AND METHODS: We performed a retrospective study of 31 consecutive cases from february 2001 to october 2007 of 17 women and 14 men, mean age 56.2 years (range: 26-88), with anatomical-pathology diagnosis of medullary thyroid cancer and suspicion of recurrence due to abnormal elevation of calcitonin and negative imaging tests. All of the patients underwent whole body FDG-PET scan with a dedicated PET or PET-CT 60 minutes after intravenous injection of 333-434 MBq of (18)F-FDG. Results were confirmed by pathology study in 45.2% of the patients and by clinical follow-up with a mean of 4 years (range: 16 m-8 years) RESULTS: Sensitivity was 88%, specificity 84.6%, positive predictive value 88%, negative predictive value 84.6% and diagnostic accuracy 87%. The results of the FDG PET modified the therapeutic strategy in 14 cases (45.2%). A comparison was made of the mean values of calcitonin using the Student's "t" test between positive PET studies for the disease and negative ones. No significant differences were found (P=.3). CONCLUSIONS: In patients with MTC and suspected recurrence with elevated calcitonin and negative imaging test, the FDG is the best test for the diagnosis of occult recurrence in MTC with elevated calcitonin and negative imaging techniques with elevated clinical impact. It facilitates the therapeutic management of the patients with MTC recurrence, and should be included in the diagnosis algorithm in these patients.

Evaluación de la eficacia y del impacto clínico de la PET- 18F-FDG en el diagnóstico de recurrencia del carcinoma medular de tiroides con calcitonina elevada y pruebas de imagen negativas / Evaluation of efficacy and clinical impact of 18F-FDG-PET in the diagnosis of recurrent medullary thyroid cancer with increased calcitonin and negative imaging test

Objetivo. Evaluar la eficacia y el impacto clínico de la PET-FDG en el diagnóstico de sospecha de recurrencia de carcinoma medular de tiroides (CMT), en pacientes con calcitonina elevada y pruebas de imagen negativas. Material y métodos. Estudiamos retrospectivamente a 31 pacientes consecutivos de febrero de 2001 a octubre de 2007; 17 mujeres y 14 hombres con una edad media de 56,2 años (rango: 26-88), diagnóstico anatomopatológico de carcinoma medular de tiroides y sospecha de recurrencia por elevación patológica de calcitonina y pruebas de imagen negativas. A todos los pacientes se les realizó PET/PET-TAC corporal 60min post-inyección intravenosa de 333-434 MBq de 18F-FDG. Los resultados se confirmaron mediante anatomía patológica en el 45,2% de los pacientes y por seguimiento clínico/radiológico en el 54,8% durante un período de seguimiento medio de 4 años (rango: 16 m-8 años). Resultados. Se obtuvo una sensibilidad del 88%, especificidad del 84,6%, valor predictivo positivo del 88%, valor predictivo negativo del 84,6% y exactitud diagnóstica del 87%. Los resultados de la PET-FDG modificaron la actitud terapéutica en 14 casos (45,2%). Se compararon las medias de los valores de calcitonina entre PET positivos para enfermedad y negativos, mediante la prueba de la «t» de Student no encontrando diferencia significativa (p=0,3). Conclusiones. La PET-18F-FDG es la prueba idónea para el diagnóstico de recurrencia oculta en CMT con calcitonina elevada y técnicas de imagen negativas, con elevado impacto clínico facilitando el manejo terapéutico de los pacientes con recurrencia de CMT, debiendo ser incluida en el algoritmo diagnóstico de estos pacientes(AU)

Aim. To evaluate the efficacy and clinical impact of the FDG-PET in the diagnosis of suspicion of recurrence of medullary thyroid cancer (MTC) in patients with elevated serum calcitonin and negative imaging test. Material and methods. We performed a retrospective study of 31 consecutive cases from february 2001 to october 2007 of 17 women and 14 men, mean age 56.2 years (range: 26-88), with anatomical-pathology diagnosis of medullary thyroid cancer and suspicion of recurrence due to abnormal elevation of calcitonin and negative imaging tests. All of the patients underwent whole body FDG-PET scan with a dedicated PET or PET-CT 60minutes after intravenous injection of 333-434 MBq of 18F-FDG. Results were confirmed by pathology study in 45.2% of the patients and by clinical follow-up with a mean of 4 years (range: 16 m-8 years). Results. Sensitivity was 88%, specificity 84.6%, positive predictive value 88%, negative predictive value 84.6% and diagnostic accuracy 87%. The results of the FDG PET modified the therapeutic strategy in 14 cases (45.2%). A comparison was made of the mean values of calcitonin using the Student's «t» test between positive PET studies for the disease and negative ones. No significant differences were found (P=.3). Conclusions. In patients with MTC and suspected recurrence with elevated calcitonin and negative imaging test, the FDG is the best test for the diagnosis of occult recurrence in MTC with elevated calcitonin and negative imaging techniques with elevated clinical impact. It facilitates the therapeutic management of the patients with MTC recurrence, and should be included in the diagnosis algorithm in these patients(AU)

Intoxicaciones intencionadas y accidentales de fauna silvestre y doméstica en España: diferencias entre Comunidades Autónomas / Intentional and accidental poisoning of wild and domestic animals in Spain: differences between regions

En este estudio se han analizado 1.157 casos sospechosos de intoxicación de fauna silvestre y doméstica en el medio natural (1.800 animales y 340 cebos) procedentes de diversas Comunidades Autónomas (CCAA) españolas durante el periodo 2004-2010. Se ha detectado un 41,2% de casos positivos (40,8% de animales y 52,6% de cebos). En los carnívoros domésticos la detección del tóxico llegó al 71,4%, lo que indica su utilidad como centinelas del uso de veneno en el medio natural. El 78,3% de los animales que fueron positivos a los análisis toxicológicos han sido considerados como intoxicaciones intencionadas. Las aves rapaces diurnas fueron el grupo más afectado por las intoxicaciones (43,6% del total de animales positivos), seguido de los mamíferos carnívoros (27,1%). Los tóxicos más frecuentemente detectados fueron insecticidas anticolinesterásicos (cebos/animales: 80,4%/65,8%), seguidos de rodenticidas anticoagulantes (5%/19,6%), estricnina (2,2%/6,5%) y arsénico (4,5%/2,3%). De las diferencias observadas entre CCAA destaca la preponderancia en el uso de estricnina en Asturias, rodenticidas anticoagulantes en Castilla y León, insecticidas organofosforados en Aragón, insecticidas carbamatos en Castilla-La Mancha y Madrid, y la aparición de otros venenos, como alfa-cloralosa o barbitúricos, en Cataluña. En resumen, el 82,3% de las intoxicaciones intencionadas fueron debidas a anticolinesterásicos y el 85,5% de las accidentales a rodenticidas anticoagulantes. En futuras regulaciones de plaguicidas y biocidas se debería tener en cuenta el riesgo del uso ilegal en la preparación de cebos envenenados que comporta la comercialización de formulados con alta riqueza de ingredientes activos con baja DL50 (AU)

In this study we have analyzed 1,157 suspected cases of poisoning of wild and domestic animals in the natural environment (1,800 animals and 340 baits) from different Spanish regions during the period 2004- 2010. We detected 41.2% of positive cases (40.8% of animals and 52.6% of baits). In domestic carnivores detection of toxic compounds reached 71.4%, indicating its usefulness as sentinels of the use of poison in the environment. In those animals positive for toxicological analysis, 78.3% have been considered as intentional poisonings. The diurnal raptors were most affected by poisoning (43.6% of positives), followed by carnivorous mammals (27.1%). The most frequently detected toxicants were anticholinesterase insecticides (baits/animals: 80.4%/65.8%), followed by anticoagulant rodenticides (5%/19.6%), strychnine (2.2%/6.5%) and arsenic (4.5%/2.3%). The differences observed between regions underlines the dominance in the use of strychnine in Asturias, anticoagulant rodenticides in Castilla y Leon, organophosphate insecticides in Aragon, carbamate insecticides in Castilla-La Mancha and Madrid, and the emergence of other poisons, such as alpha-chloralose or barbiturates, in Catalonia. In summary, 82.3% of intentional poisonings were due to anticholinesterase pesticides and 85.5% of accidental anticoagulant rodenticides. Future regulations of pesticides and biocides should take into account the risk of illegal use in the preparation of poisoned baits which involves the marketing of formulations with high richness of active ingredients with low LD50 (AU)

Tomografía por emisión de positrones con 18F-fluorodeoxy-glucosa en un caso de plasmocitoma solitario de paladar blando / 18F-FDG PET-CT in a case of solitary plasmacytoma of the soft palate

El plasmocitoma solitario es un tumor poco frecuente de células plasmáticas que ocasionalmente puede aparecer en la región de la cabeza y el cuello. Por su presentación inicial debe diferenciarse del mieloma múltiple. Describimos un caso de plasmocitoma solitario de paladar y analizamos el papel de la tomografía por emisión de positrones con 18F-fluorodeoxy-glucosa en su estadificación inicial(AU)

Solitary plasmacytoma is an uncommon tumor of plasma cells that can appear in the head and neck. It must be differentiated from multiple myeloma because of its initial presentation. A case of solitary plasmacytoma on the palate is presented. Furthermore, role of 18F-fluorodeoxyglucose Positron Emission Tomography (18F-FDG-PET) in its initial staging is analyzed(AU)

[18F-FDG PET-CT in a case of solitary plasmacytoma of the soft palate]. / Tomografía por emisión de positrones con ¹8F-fluorodeoxy-glucosa en un caso de plasmocitoma solitario de paladar blando.

Solitary plasmacytoma is an uncommon tumor of plasma cells that can appear in the head and neck. It must be differentiated from multiple myeloma because of its initial presentation. A case of solitary plasmacytoma on the palate is presented. Furthermore, role of ¹8F-fluorodeoxyglucose Positron Emission Tomography (¹8F-FDG-PET) in its initial staging is analyzed.

[Clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer]. / Impacto clínico de la PET-FDG en pacientes con sospecha de recurrencia de cáncer de ovario.

AIM: To evaluate the efficacy and clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer. METHODS: Between October 2001 and October 2006, we retrospectively studied 49 FDG-PET performed in 40 women (age: 52.4 +/- 12.2 years) with ovarian cancer, who had suspicion of recurrent disease by positive morphologic imaging tests (MIT) or increased tumour markers and negative MIT. All patients underwent whole body FDG-PET after the injection of 370-434 MBq of (18)FDG. The results were confirmed by histology in 31 cases, and by clinical-radiological follow-up in 18. RESULTS: Prevalence of disease was 79.6 %. We obtained a global sensitivity and positive predictive value of 87.2 % and 87.2 %, and an accuracy of 79.6 %. Results led to a change in the patient's management in 25 cases (51 %). Subgroup results were: Sensitivity of 81.8 % in patients with increased tumour markers and negative MIT, and 89.3 % in patients with operable malignant lesions. CONCLUSIONS: FDG-PET has high sensitivity and clinical impact in patients with suspicion of recurrent ovarian cancer. Better results were obtained in patients with increased tumour markers and negative MIT.

Impacto clínico de la PET-FDG en pacientes con sospecha de recurrencia de cáncer de ovario / Clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer

Objetivo. Evaluar la eficacia y el impacto clínico de la PET-18FDG en las pacientes con sospecha de recidiva de cáncer de ovario. Método. Entre octubre de 2001 y octubre de 2006, estudiamos de forma retrospectiva 49 exploraciones PET-FDG realizadas a 40 mujeres (edad: 52,4 ± 12,2 años) diagnosticadas de carcinoma de ovario, en las que se sospechaba recurrencia de su enfermedad bien por técnicas morfológicas (medios diagnósticos convencionales [MDC]), bien por elevación de marcadores tumorales (MMTT) con MDC negativas. A todas se les realizó PET corporal tras la inyección de 370-434 MBq de 18FDG. Los resultados se confirmaron por anatomía patológica en 31 pacientes y por seguimiento clínico/radiológico en 18. Resultados. La prevalencia de enfermedad en la muestra estudiada fue del 79,6 %. Se obtuvieron una sensibilidad y un valor predictivo positivo globales del 87,2 y 87,2 %, y una exactitud diagnóstica del 79,6 %. Los resultados de los estudios indujeron un cambio en el manejo terapéutico en 25 casos (51 %). La sensibilidad fue del 81,8 % en el subgrupo de pacientes con elevación de MMTT y MDC negativas, y del 89,3 % en el de pacientes con lesiones susceptibles de cirugía con intención curativa. Conclusiones. La PET-18FDG tiene una alta sensibilidad e impacto clínico en la sospecha de recurrencia de carcinoma de ovario, obteniéndose los mejores resultados en el subgrupo de pacientes con MMTT elevados y MDC negativos

Aim. To evaluate the efficacy and clinical impact of FDG-PET in patients with suspected recurrent ovariancancer. Methods. Between October 2001 and October 2006, we retrospectively studied 49 FDG-PET performed in 40 women (age: 52.4 ± 12.2 years) with ovarian cancer, who had suspicion of recurrent disease by positive morphologic imaging tests (MIT) or increased tumour markers and negative MIT. All patients underwent whole body FDG-PET after the injection of 370-434 MBq of 18FDG. The results were confirmed by histologyin 31 cases, and by clinical-radiological follow-up in 18. Results. Prevalence of disease was 79.6%. We obtained a global sensitivity and positive predictive value of 87.2 % and 87.2 %, and an accuracy of 79.6 %. Results led to a change in the patient’s management in 25 cases (51 %). Subgroup results were: Sensitivity of 81.8 % in patients with increased tumour markers and negative MIT, and 89.3 % in patients with operable malignant lesions. Conclusions. FDG-PET has high sensitivity and clinical impact in patients with suspicion of recurrent ovarian cancer. Betterresults were obtained in patients with increased tumourmarkers and negative MIT

Levels of heavy metals and metalloids in critically endangered Iberian lynx and other wild carnivores from Southern Spain.

The Iberian lynx (Lynx pardinus) is the most endangered felid in the world with a wild population which probably stands at less than 200 individuals inhabiting two areas in Southern Spain (Doñana and Sierra Morena) that are known to have been contaminated by heavy metals and metalloids due to a long history of mining activities. This contamination may pose a threat to long term conservation efforts and hence, the concentrations of seven elements (As, Se, Cd, Zn, Cu, Pb, Hg) were determined in the liver, muscle and bone of 9 lynx, as well as 17 red foxes (Vulpes vulpes), 11 Egyptian mongooses (Herpestes ichneumon), 4 common genets (Genetta genetta) and 1 Eurasian badger (Meles meles). The mean concentrations found were below the threshold levels indicative of chronic intoxication in all the species studied. In general, genet and red fox were species with the highest concentrations of several elements in Doñana, whilst Iberian lynx had the lowest levels of most of them. Lynx from Sierra Morena had significantly higher concentrations of bone Pb (2.05 microg/g d.w.) than those from Doñana (0.13 microg/g d.w.), probably due to the mineralised underlying geology and/or the abandoned mine workings in Sierra Morena. Egyptian mongoose presented liver concentrations of Hg up to 9.7 microg/g d.w. A strong relationship between Hg and Se levels was found in liver and muscle samples of all the studied species, especially in mongoose. In conclusion, levels of the studied elements do not appear to represent a significant threat for the lynx or for the other carnivores studied. However, given the critical status of the Iberian lynx, a continuous monitoring scheme remains necessary.

Transfer of lead from shot pellets to game meat during cooking.

We evaluated the transfer of Pb from shot to meat during the preparation of breasts of quails with 0, 1, 2 or 4 embedded Pb shot. A traditional Spanish recipe was used which utilizes vinegar during cooking to enhance the long-term preservation of the meat. The effect of the acidic conditions generated by the vinegar on Pb transfer was compared with the same recipe when the vinegar was substituted with water. The effect of up to 4 weeks of storage on Pb transfer has been also evaluated. The transfer of Pb from the embedded shot to the meat was much higher when cooking with vinegar than with water. However, the Pb transfer under acidic conditions did not increase significantly during long-term storage at room temperature. The consumption of only half a pickled quail per week with embedded shot may cause the provisional tolerable weekly intake (PTWI) of Pb by the Spanish consumer to be exceeded.

[F-18-fluordeoxyglucose positron emission tomography on patients with differentiated thyroid cancer who present elevated human serum thyroglobulin levels and negative I-131 whole body scan]. / PET con 18FDG en pacientes con cáncer diferenciado de tiroides que presentan niveles elevados de tiroglobulina sérica y rastreos con 131I negativos.

UNLABELLED: This study aimed to evaluate the role of Fluorine-18-fluorodeoxyglucose positron emission tomography (PET-FDG) in patients with elevated serum thyroglobulin (hTg) levels where thyroid cancer tissue does not concentrate radioiodine, rendering false-negative results on I-131 scanning. MATERIAL AND METHODS: Whole-body PET imaging using FDG was performed in 54 patients (37 female, 17 male) aged 17-88 years: 45 with papillary tumors and 9 with follicular tumors who were suspected of having recurrent thyroid carcinoma due to elevated thyroglobulin levels (hTg > 2 ng/ml) under thyroid-stimulating hormone (TSH > or = 30 microIU/ml) in whom the iodine scan was negative. All whole body scans were obtained with diagnostic doses (185 MBq). Whole body PET imaging was performed in fasting patients following i.v. administration of 370 MBq FDG while the patients were receiving full thyroid hormone replacement. Before PET, 99mTc methoxyisobutylisonitrile scintigraphy (99mTc-MIBI) was done in 14 patients and morphologic imaging in 26 by CT scan. RESULTS: Positive PET results confirmed the presence of hypermetabolic foci in 25/54 patients (46.29 %). Positive findings were found for PET-FDG in patients with hTg levels higher than 10 ng/ml receiving full thyroid hormone replacement. 99mTc-MIBI demonstrated lesions in 7/14 patients (50 %). PET-FDG and 99mTc-MIBI had congruent positive results in 4/7 patients. All the lesions found by CT were detected by PET-FDG, while recurrent disease was found in 12/21 patients with previous negative CT. CONCLUSIONS: These results suggest that PET-FDG seems to be a promising tool in the follow-up of thyroid cancer and should be considered in patients suffering from differentiated thyroid cancer with suspected recurrence and/or metastases by elevated thyroglobulin levels, and negative I-131 whole body scans. PET-FDG might be more useful at hTg levels > 10 ng/ml.

PET con 18FDG en pacientes con cáncer diferenciado de tiroides que presentan niveles elevados de tiroglobulina sérica y rastreos con 131I negativos / F-18-Fluordeoxyglucose positron emission tomography on patients with diferentiated thyroid cancer who present elevated human serum thyroglobulin levels and negative I-131 whole body scan

El objetivo de estudio fue valorar el papel de la tomografía por emisión de positrones con 18F-fluordeoxiglucosa (PET-FDG) en los pacientes con cáncer diferenciado de tiroides, niveles de tiroglobulina sérica (hTg) elevados y rastreo de cuerpo completo con radioyodo negativo (RCC). Material y métodos: Se estudiaron con PET-FDG 54 pacientes (37 mujeres y 17 hombres) con edades comprendidas entre los 17 y los 88 años, 45 con carcinomas papilares y 9 con foliculares de tiroides con sospecha de recurrencia/metástasis de su enfermedad por elevación de los niveles de hTg (hTg > 2 ngr/ml) en presencia de valores estimulantes de la TSH (≥ 30 μIU/ml) y en los que el RCC era negativo. Los RCC se realizaron con dosis diagnósticas (185 MBq). Las PET-FDG se efectuaron tras la administración i.v. en ayunas de 370 MBq de FDG hallándose el paciente bajo su tratamiento hormonal sustitutivo habitual. Previamente a la realización de la PET-FDG, 14 pacientes habían sido estudiados por gammagrafía con 99mTc-metoxi-isobutiril-isonitrilo (MIBI), mientras que a 26 se les había realizado tomografía computerizada (TC). Resultados: Un total de 25 de los 54 PET-FDG mostraron focos patológicos de captación del trazador (46,29 %). Se observó asociación significativa entre la positividad de la PET y los niveles de hTg mayores de 10 ng/ml en el momento de esta exploración (en tratamiento sustitutivo). La gammagrafía con 99mTc-MIBI era positiva en 7 de los 14 pacientes a los que se les realizó, y esta positividad fue congruente con la PET-FDG en 4/7. Todas las lesiones detectadas por la TC fueron visualizadas en la PET-FDG, mientras que 12 de los 21 pacientes con TC negativa tenían evidencia de recurrencia de la enfermedad detectada por la PET-FDG. Conclusiones: Nuestros resultados sugieren que la PET-FDG sería una técnica de gran utilidad en el seguimiento de los pacientes diagnosticados de carcinoma diferenciado de tiroides con niveles de hTg elevados y RCC negativos. Su utilidad sería superior si los valores de hTg fuesen mayores de 10 ng/ml

This study aimed to evaluate the role of Fluorine-18-fluorodeoxyglucose positron emission tomography (PET-FDG) in patients with elevated serum thyroglobulin (hTg) levels where thyroid cancer tissue does not concentrate radioiodine, rendering false-negative results on I-131 scanning. Material and methods: Whole-body PET imaging using FDG was performed in 54 patients (37 female, 17 male) aged 17-88 years: 45 with papillary tumors and 9 with follicular tumors who were suspected of having recurrent thyroid carcinoma due to elevated thyroglobulin levels (hTg > 2 ng/ml) under thyroid-stimulating hormone (TSH ≥ 30 μIU/ml) in whom the iodine scan was negative. All whole body scans were obtained with diagnostic doses (185 MBq). Whole body PET imaging was performed in fasting patients following i.v. administration of 370 MBq FDG while the patients were receiving full thyroid hormone replacement. Before PET, 99mTc methoxyisobutylisonitrile scintigraphy (99mTc-MIBI) was done in 14 patients and morphologic imaging in 26 by CT scan. Results: Positive PET results confirmed the presence of hypermetabolic foci in 25/54 patients (46.29 %). Positive findings were found for PET-FDG in patients with hTg levels higher than 10 ng/ml receiving full thyroid hormone replacement. 99mTc-MIBI demonstrated lesions in 7/14 patients (50 %). PET-FDG and 99mTc-MIBI had congruent positive results in 4/7 patients. All the lesions found by CT were detected by PET-FDG, while recurrent disease was found in 12/21 patients with previous negative CT. Conclusions: These results suggest that PET-FDG seems to be a promising tool in the follow-up of thyroid cancer and should be considered in patients suffering from differentiated thyroid cancer with suspected recurrence and/or metastases by elevated thyroglobulin levels, and negative I-131 whole body scans. PET-FDG might be more useful at hTg levels > 10 ng/mlThis study aimed to evaluate the role of Fluorine-18-fluorodeoxyglucose positron emission tomography (PET-FDG) in patients with elevated serum thyroglobulin (hTg) levels where thyroid cancer tissue does not concentrate radioiodine, rendering false-negative results on I-131 scanning. Material and methods: Whole-body PET imaging using FDG was performed in 54 patients (37 female, 17 male) aged 17-88 years: 45 with papillary tumors and 9 with follicular tumors who were suspected of having recurrent thyroid carcinoma due to elevated thyroglobulin levels (hTg > 2 ng/ml) under thyroid-stimulating hormone (TSH ≥ 30 μIU/ml) in whom the iodine scan was negative. All whole body scans were obtained with diagnostic doses (185 MBq). Whole body PET imaging was performed in fasting patients following i.v. administration of 370 MBq FDG while the patients were receiving full thyroid hormone replacement. Before PET, 99mTc methoxyisobutylisonitrile scintigraphy (99mTc-MIBI) was done in 14 patients and morphologic imaging in 26 by CT scan. Results: Positive PET results confirmed the presence of hypermetabolic foci in 25/54 patients (46.29 %). Positive findings were found for PET-FDG in patients with hTg levels higher than 10 ng/ml receiving full thyroid hormone replacement. 99mTc-MIBI demonstrated lesions in 7/14 patients (50 %). PET-FDG and 99mTc-MIBI had congruent positive results in 4/7 patients. All the lesions found by CT were detected by PET-FDG, while recurrent disease was found in 12/21 patients with previous negative CT. Conclusions: These results suggest that PET-FDG seems to be a promising tool in the follow-up of thyroid cancer and should be considered in patients suffering from differentiated thyroid cancer with suspected recurrence and/or metastases by elevated thyroglobulin levels, and negative I-131 whole body scans. PET-FDG might be more useful at hTg levels > 10 ng/ml

[Evaluation of efficacy and clinical impact of FDG-PET in patients with suspicion of recurrent colorectal cancer]. / Evaluación de la eficacia y del impacto clínico de la PET-FDG en pacientes con sospecha de recurrencia de cáncer colorrectal.

AIMS: To evaluate the utility and clinical impact of Positron Emission Tomography with FDG (FDG-PET) in patients with suspected recurrent colorectal cancer (RCR). MATERIALS AND METHODS: Eighty five (85) patients with suspicion of RCR (Group A: 35 for increased tumor markers and negative imaging tests, Group B: 25 operable malignant lesions and Group C: 25 with non-conclusive morphological tests) were studied retrospectively. In all patients a whole body scan was performed with FDG-PET. In 29 cases the results were confirmed by histology and clinical evolution (follow-up period > 12 months) and imaging test in 56. RESULTS: Prevalence of RCR was 89.4 %. FDG-PET was positive in 30/35 patients in Group A, with confirmation in 29 cases (PPV: 96.6 %) and 4/5 were true negative (TN) (NPV: 80 %). FDG-PET enabled surgery for 6 patients. In Group B, PET was positive in 22/25, and all of them had confirmation (PPV: 100 %) but surgery was performed in only 7 patients. NPV was 66.6 %. Out of the 25 cases of Group C, FDG-PET obtained 21 TP, 1 FP case, 1 TN, 2 FN, and was able to avoid surgery in 8 patients (PPV: 95.4 % and NPV: 33.3 %). Overall sensitivity, specificity, PPV, NPV and accuracy were 94.7 %, 77.7 %, 97.2 %, 63.3 % and 92.9 %, respectively. CONCLUSIONS: FDG-PET has high clinical impact in patients with suspicion of recurrent colorectal cancer, and should be incorporated in the diagnostic protocols before making a surgery decision.

[Recombinant human thyrotropin in the follow-up of patients with differentiated thyroid carcinoma]. / La TSH humana recombinante en el seguimiento de pacientes con cáncer diferenciado de tiroides.

PURPOSE: To determine the value of the use of radio-iodine scanning diagnostic and radio-iodine therapy during the follow-up of advanced differentiated thyroid cancer without stopping thyroid hormone suppression therapy. MATERIAL AND METHODS: We performed 7 radio-iodine scans and 4 radioiodine therapies in 5 men and 1 woman, aged 39 to 79 years. Five patients had papillary thyroid cancer and one follicular thyroid cancer. Human recombinant thyrotropin was given intramuscularly at a dose of 0.9 mg/ml once a day for two days. Twenty-four hours after the second dose, serum thyrotropin, thyroglobulin (Tg) and thyroglobulin autoantibodies were measured and each patient was given 2 mCi of 131I in postsurgery scans and 5 mCi of 131I in patients previously treated with 131I. Whole-body scans were obtained within 54 hours of injection and in the cases of diagnostic uncertainty a second scan was performed 72 hours after the injection. RESULTS: Four scans were positive and two were negative. One positive scan patient was not treated due to a serious clinical condition. An effective increase of serum TSH was observed in all 6 patients. Four patients had an effective increase of serum Tg; the other 2 cases had a decrease of serum Tg: One case was undifferentiated and in the other case the mass was smaller after surgery. CONCLUSIONS: rhTSH is an effective means of stimulating TSH levels and allowing scan and/or radioiodine treatment. rhTSH has no significant adverse effects. The use of rhTSH avoids all the disadvantages of hypothyroidism and maintains quality of life.

La TSH humana recombinante en el seguimiento de pacientes con cáncer diferenciado de tiroides / Recombinant human thyrotropin in the follow-up of patients with differentiated thyroid carcinoma

Objetivo: Estimar el valor del uso de TSH humana recombinante (rhTSH), para el rastreo y tratamiento con I 131 en pacientes con CDT avanzado, en los que se desaconseja la interrupción de toma exógena de hormonas tiroideas.Material y métodos: Se realizan 7 rastreos y 4 tratamientos con I 131, en cinco hombres y una mujer, edad de 39 a 79 años.5 con carcinoma papilar de tiroides y 1 con carcinoma folicular.Pauta de administración de rhTSH: dos inyecciones intramusculares de 0,9 mg/ml, separadas 24 horas, a las 24 horas de la segunda inyección se determina en suero TSH, Tg y AbTg y se administra dosis trazadora de I131 (2 mCi en rastreos postcirugía y 5 mCi en pacientes ya tratados con I131); realizando a las 54 horas en todos los pacientes, y a las 72 horas en caso de duda diagnóstica, rastreo de cuerpo completo e imágenes estáticas de áreas de interés, en una gammacámara de un detector, con colimador de alta energía.Resultados: 4 rastreos positivos ( +) y 2 negativos (-). Hubo 1 rastreo positivo que no recibió tratamiento por situación clínica grave. En los 6 pacientes se elevó eficazmente la TSH, la Tg lo hizo en 4. En los 2 restantes la menor producción a la esperada de Tg tras el estímulo con rhTSH se explica por desdiferenciación del tumor y por disminución de la masa tumoral tras intervención quirúrgica.Conclusiones: La rhTSH eleva eficazmente la TSH, permitiendo el rastreo y/o el tratamiento con I131. Es bien tolerada y no presenta efectos adversos significativos. Evita las molestias de la situación de hipotiroidismo en pacientes de riesgo, manteniendo su calidad de vida (AU)