Clinical Impact of PET With 18F-FDG and 11C-PIB in Patients With Dementia in a Developing Country.

Introduction: The objective of this study was to evaluate the clinical impact PET with 18F-FDG and 11C-PIB in patients with dementia in a developing country. Methodology: Retrospective study of the patients referred for the evaluation of dementia to the only PET center in Uruguay. A total of 248 patients were identified, from which 70 patients were included based on the availability of medical history and clinical follow-up. Main outcomes included change in diagnosis, diagnostic dilemma and AD treatment. We evaluated the association of clinical outcomes with PET concordance with baseline diagnosis, diagnostic dilemma, level of education, AD pathology/Non-AD pathology (AD/Non-AD), baseline diagnosis and 11C-PIB PET result. Results: Baseline clinical diagnosis was concordant with 18F-FDG and 11C-PIB PET results in 64.7 and 77.1% of the patients, respectively. Change in diagnosis after PET was identified in 30.0% of the patients and was associated with discordant 18F-FDG (p = 0.002) and 11C-PIB (p < 0.001) PET results, previous diagnostic dilemma (p = 0.005), low education (p = 0.027), Non-AD baseline diagnosis (p = 0.027), and negative 11C-PIB PET result (p < 0.001). Only the last variable remained significant in the multivariate analysis (adjusted p = 0.038). Diagnostic dilemma decreased after PET from 15.7 to 7.1% (p = 0.11) and was associated with Non-AD diagnosis (p = 0.002) and negative 11C-PIB PET result (p = 0.003). Change in AD treatment after PET occurred in 45.7% of the patients. Conclusion: 18F-FDG and 11C-PIB PET had a significant clinical impact in terms of change in diagnosis and treatment in patients with dementia in a developing country, similar to that reported in high-income countries.

Protocolo combinado de 99mTc-Ciprofloxacina y 99mTc-MDP en el diagnóstico de osteomielitis y prótesis articular infectada / 99mTc-ciprofloxacin/99mTc-MDP combined protocol in the diagnosis of osteomyelitis and infected joint prosthesis

Introducción. El centellograma óseo con 99mTc-MDP es una técnica útil en el diagnóstico de osteomielitis, sin embargo, presenta especificidad limitada en presencia de patología ósea previa (osteomielitis complicada). La 99mTc-ciprofloxacina es uno de los radiofármacos más difundidos para la detección de infecciones óseas, aunque persisten controversias sobre su rendimiento diagnóstico. Objetivo. Determinar el valor clínico del protocolo combinado de centellograma con 99mTc-ciprofloxacina y 99mTc-MDP en el diagnóstico de osteomielitis complicada y prótesis articular infectada. Materiales y métodos 37 pacientes con sospecha clínica de osteomielitis complicada o prótesis infectada fueron estudiados mediante centellograma con 99mTc-ciprofloxacina y 99mTc-MDP. 26/37 pacientes presentaban fractura previa, 7 prótesis de rodilla y 4 prótesis de cadera. En todos ellos se realizó seguimiento clínico y bacteriológico. Resultados. El método presentó sensibilidad de 94 por ciento, especificidad de 79 por ciento, valor predictivo positivo de 81 por ciento y valor predictivo negativo de 94 por ciento, con una exactitud de 86 por ciento. Conclusiones. El protocolo combinado de 99mTc-ciprofloxacina y 99mTc-MDP presenta elevado rendimiento para el diagnóstico de osteomielitis complicada y prótesis articular infectada.

Introduction. Bone scintigraphy with 99mTc-MDP is a useful technique in the diagnosis of osteomyelitis, however, has limited specificity in the presence of previous bone pathology (complicated osteomyelitis). 99mTc-ciprofloxacin is one of the most widely used radiotracers for the detection of bone infection, although controversies persist on its diagnostic performance. Objective To determine the clinical value of 99mTc-ciprofloxacin/99mTc-MDP combined protocol in the diagnosis of complicated osteomyelitis and infected joint prosthesis. Materials and methods 37 patients with clinically suspected complicated osteomyelitis or infected prosthesis were studied with 99mTc-ciprofloxacin and 99mTc-MDP scintigraphy. 26/37 patients had previous fractures, 7 had knee replacements and 4 had hip replacements. All of the patients underwent clinical and bacteriological follow-up. Results. The method presented sensitivity of 94 percent, 79 percent specificity, 81 percent positive predictive value and 94 percent negative predictive value, with an accuracy of 86 percent. Conclusions. The combined protocol using 99mTc-ciprofloxacin/99mTc-MDP showed high diagnostic performance in complicated osteomyelitis and infected joint prosthesis.

[99mTc-OCTREOTIDE in patients with neuroendocrine tumors from the GI tract]. / 99mTc-OCTREOTIDE en pacientes con tumores neuroendócrinos gastroenteropancreáticos.

INTRODUCTION: It has been demonstrated that scintigraphy with somatostatin analogues is useful for the diagnosis, staging and follow up of patients with neuroendocrine tumors from the gastrointestinal tract (NET-GIT). Some studies suggest that the use of 99mTc-Hydrazinonicotinyl-Tyr3-octreotide (99mTc-HYNIC-TOC) yields similar diagnostic results than the use of 111In-DTPA-octreotide. OBJECTIVE: To determine the clinical value of scintigraphy using 99mTc-HYNIC-TOC for the detection of primary and secondary lesions in patients with NET-GIT. METHODS: From September 2004 to May 2009, 32 patients (17 women, age range 18 to 82 years old) with histologically proven or clinically suspected NET-GIT underwent scintigraphy using 99mTc-HYNIC-TOC Patients underwent a whole body scan, with additional static images of abdomen and pelvis, followed by SPECT at 4-hrs post injection of 925 MBq of the tracer. Patients underwent clinical, imaging and histopathology follow-up during 3 to 18 months. RESULTS: Histopathology demonstrated carcinoid tumor in 20 patients, insulinoma in 2, gastrinoma in 2 and non-specific NET-GIT in 6. Total sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 87%, 100%, 100%, 89% and 94%, respectively. To detect the primary lesion, the values were 94%, 100% 100%, 94% and 97%, respectively and to detect secondary lesions, 79%, 100%, 100%, 86% and 91%, respectively. CONCLUSIONS: 99mTc-HYNIC-TOC is a specific somatostatin analog, with high affinity to receptor subtype SST-2, widely available and affordable by Latin American countries. It has a good performance to be used for diagnosis, staging and follow-up of patients with NET-GIT.