18F-fallypride and 11C-methionine positron emission tomography/computed tomography for the study of prolactinomas and nonfunctioning pituitary adenomas: A case series.

Some studies have assessed the expression of dopaminergic dopamine 2 (D2)/3 receptors in prolactinomas and nonfunctioning pituitary adenomas (NFPA) by positron emission tomography/computed tomography (PET/CT) with 11C-raclopride, proving that this modality can be useful to predict the response to treatment with dopamine agonists. However, the use of 11C-labeled radiotracers is limited, as it requires a cyclotron in the PET center. 18F-fallypride is a radiotracer that has proven useful in assessing the expression of D2/3 receptors. As it is labeled with 18F, it can be produced and transported to distant PET centers. There are no studies on the usefulness of 18F-fallypride for the evaluation of patients with prolactinomas and NFPA. The aim of this study was to describe the first case series of patients with prolactinomas and NFPA studied with 18F-fallypride and 11C-methionine PET/CT to reveal D2/3 expression and amino acid (AA) metabolism. 18F-fallypride and 11C-methionine uptake were assessed in a case series of six patients, five with prolactinomas and one with a NFPA, and compared with clinical presentation and follow-up at 6-18 months. All patients presented with macroadenomas, with a wide range of AA metabolism, as revealed by 11C-methionine PET/CT. 18F-fallypride PET/CT identified low to moderate/high D2/3 expression in the tumors. The patient that presented low expression of D2/3 in the tumor and high AA metabolism showed a poor response to DA therapy. 18F-fallypride was able to reveal D2/3 receptor expression in prolactinomas and NFPA, with the advantage of been a more accessible radiotracer in comparison with previous 11C labeled analogs.

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.

Revascularización miocárdica biológica complementaria a la revascularización miocárdica quirúrgica convencional. Comunicación preliminar de estudio prospectivo de casos y controles, randomizado y doble ciego / Biological myocardial revascularization complementary to conventional surgical myocardial revascularization Preliminary communication of a prospective, randomized, double-blind case-control study

Introducción: la revascularización miocárdica quirúrgica (RVMQ) incompleta es un factor determinante en la reaparición precoz de angina y determina una menor sobrevida para los pacientes. Objetivo: el objetivo del presente trabajo es evaluar la eficacia perfusional de la terapia angiogénica celular con células derivadas de la médula ósea (CMO) autólogas por inyección directa intramiocárdica complementaria a la RVMQ convencional. Material y método: la evaluación perfusional luego de la cirugía se realiza a los tres, seis y 12 meses mediante SPECT y ecocardiograma Doppler Tisular-Strain (DTI-Strain). Resultados: en esta comunicación preliminar (precedida por ocho casos pilotos) se reportan resultados de cuatro pacientes (dos casos y dos controles) que completaron el seguimiento al tercer mes, teniendo todos oclusión crónica de coronaria derecha (CD) sin recanalización, fracción de eyección del ventrículo izquierdo (FEVI) media de 50%. En los territorios de la descendente posterior (DP) y posterolateral (PL) de CD se inyectó un promedio de 5,7 x 106 células CD34+ autólogas en un volumen promedio de 5 ml por territorio. En el control perfusional con SPECT al tercer mes de los casos se registró un incremento perfusional en los territorios inyectados de aproximadamente 10%. En los controles, los sectores miocárdicos no revascularizados tuvieron un decremento perfusional en promedio de 3%. En el DTI-Strain se observó mejoría de los valores en todas las muestras estudiadas en el caso con FEVI conservada, y peoría en el caso con FEVI en rango inferior. La terapia celular angiogénica con CMO autólogas por vía intramiocárdica tiene beneficios prefusionales, es una técnica factible y segura complementaria al tratamiento quirúrgico.

Summary Introduction: incomplete surgical myocardial revascularization is a determining factor for early flare of subsequent angina which results in lower patient survival. Objective: the present study aims to evaluate the perfusional efficacy of cell angiogenic therapy, using autologic bone-marrow derived stem cells, by means of direct intramyocardial injections, as a complementary therapy when combined with myocardial surgical revascularization. Method: perfusional assessment subsequent to surgery is performed after three, six and twelve months with Single Photon Emission Computed Tomography (SPECT) and DTI-Strain. Results: the present preliminary communication/notice (preceded by eight pilot cases) reports results obtained in four patients (two cases and two controls), completed follow-up in the third month, all of which evidenced chronic right coronary (RC) occlusion with no reversal, 50% average left ventricle ejection fraction. An average of 5.7 x 106 CD34+ autologic cells was injected into the descending posterior and posterolateral territory. The average injection volume was 5 ml per territory. Upon SPECT perfusional control in the third month, a 10% perfusional increase was detected in the injected territories. As to the control cases, nonrevascularized myocardial sectors evidenced a perfusional decrease of 3%, on average. DTI-Strain showed values improvement for all samples studied in the case of the preserved left ventricle ejection fraction (LVEF), and worsening in the LVEF lower range. Angiogenic cell therapy by intramyocardial autologic bone-marrow stem cells implies perfusional benefits. It is a feasible and safe technique to complement surgical treatment.

Résumé Introduction: la revascularisation myocardique chirurgicale (RVMQ) incomplète est un facteur primordial à la réapparition précoce d’angine et détermine une survie raccourcie des patients. Objectif: le but de ce travail est d’évaluer l’efficacité de perfusion de la thérapie angiogénique cellulaire avec des cellules extraites de la moelle osseuse (CMO) autologues par injection directe intra-myocardique complémentaire à la RVMQ conventionnelle. Matériel et méthode: l’évaluation de la perfusion post-chirurgicale est faite trois, six et douze mois après avec SPECT et échocardiogramme Doppler Tisular-Strain (DTI-Strain). Résultats: dans cette communication préalable, précédée de huit cas pilotes, on reporte les résultats de quatre patients (deux cas et deux contrôles) ayant complété le suivi au bout de trois mois et présentant tous occlusion chronique de coronaire droite (CD) sans recanalisation, fraction d’éjection du ventricule gauche (FEVG) moyenne de 50%. Dans les territoires de la descendante postérieure (DP) et postéro latérale (PL) de CD on a injecté une moyenne de 5,7 x 106 cellules CD34+autologues dans un volume moyen de 5 ml par territoire. Lors du contrôle de perfusion avec SPECT des cas au troisième mois, on a repéré une hausse de perfusion dans les territoires injectés de 10% environ, les secteurs myocardiques non revascularisés ayant subi une décroissance perfusionnelle de 3% environ. Au DTI-Strain, on a observé une amélioration des valeurs dans tous les échantillons prélevés au cas de FEVG conservée et aggravation au cas avec FEVG à rang inférieur. La thérapie cellulaire angiogénique avec CMO autologues par voie intra-myocardique a des bénéfices de perfusion, est une technique faisable et sûre complémentaire au traitement chirurgical.

Resumo Introdução: a revascularização cirúrgica incompleta do miocárdio (RVCM) é um fator determinante no reaparecimento precoce da angina que implica uma sobrevida menor para os pacientes. Objetivo: o objetivo deste trabalho é avaliar a eficácia perfusional da terapia angiogênica celular com células autólogas obtidas da medula óssea por injeção direta intra-miocárdica como complemento a RVCM tradicional. Material e método: a avaliação perfusional pós-cirurgia é feita aos três, seis e doze meses usando SPECT e ecocardiograma Doppler Tisular-Strain (DTI-Strain). Resultados: nesta comunicação preliminar, (depois de oito casos piloto) relatamos os resultados de quatro pacientes (dois casos e dois controles) que terminaram o seguimento no terceiro mês, todos com oclusão crônica de coronária direita (CD) sem recanalizaçao com fração de ejeção do ventrículo esquerdo (FEVE) média de 50%. Na região do ramo descendente posterior (DP) e póstero-lateral (PL) da CD, injetaram-se uma média de 5,7 x 106 células CD34+ autólogas em um volume médio de 5 ml por região. No controle perfusional dos casos, realizado no terceiro mês, foi registrado um aumento da perfusão nas regiões injetadas de aproximadamente 10%. Nos controles, os setores do miocárdio não revascularizados apresentaram uma redução média da perfusão de 3%. No DTI-Strain foi observada uma melhora dos valores em todas as amostras estudadas no caso com FEVE conservada, e uma piora no caso com FEVE com valor inferior. A terapia celular angiogênica com CMO autólogas por via intra-miocárdica apresenta melhoras da perfusão, é uma técnica viável e segura, complementar ao tratamento cirúrgico.

99mTc-HYNIC octreotide in neuroblastoma.

Disease status assessment of neuroblastoma patients requires computed tomography (or magnetic resonance imaging), bone scan, metaiodobenzylguanidine (MIBG) scan, bone marrow tests, and urine catecholamine measurements. There is no clinical experience concerning the evaluation of these patients by means of technetium-99m (99mTc)-somatostatin analog scintigraphy. Furthermore, these radiopharmaceuticals are promising imaging agents owing to their lower cost, availability, dosimetry, and ease of preparation. An 8-year-old boy already diagnosed with stage-IV neuroblastoma received chemotherapy. In the follow-up, after obtaining the parents' informed consent, iodin 131 (131I)-MIBG and 99mTc-6-hydrazinopyridine-3-carboxylic acid (HYNIC)-octreotide scans were done on separate days to evaluate tumor extension. Even as the 131I-IBG scan showed mild diffuse uptake in the projection of both lung hili, the 99mTc-HYNIC-octreotide scan showed multiple axial and appendicular bone uptakes and paravertebral, abdominal, mediastinal, and supraclavicular ganglionar uptakes. The 99mTc-HYNIC-octreotide showed much more lesion extension than the 131I-MIBG. Therefore, 99mTc-HYNIC-octreotide may be a promising radiopharmaceutical for the evaluation of neuroblastoma patients. This finding justifies the preliminary evaluation of this tracer in the context of a clinical trial.

Dobutamine modulated Tc-99m MIBI scintigraphy in secondary hyperparathyroidism in uremic patients.

The aim of this study was to determine if low-dose dobutamine infusion can enhance Tc-99m methoxy isobutyl isonitrile (MIBI) uptake of hyperfunctioning parathyroid glands of patients with secondary hyperparathyroidism (SHP). We studied 24 patients with chronic renal failure and SHP. Median age of the sample was 47.5 years. A single-tracer, double-phase technique was performed, acquiring planar images of the neck and thorax after the injection of 740 to 1110 MBq (20-30 mCi) of Tc-99m MIBI. After 2 to 7 days, the study was repeated after the infusion of low-dose dobutamine of 2.0 microg . kg . min for 60 minutes. The scan was considered positive for hyperfunctioning parathyroid tissue when an area of increased uptake that persisted on late imaging was found. Parathyroid-to-thyroid count rates (PT/T) were calculated for each abnormal focus. Hyperplasic parathyroid tissue was confirmed in 12 of 24 patients who underwent neck surgery whereas the remaining group had persistent or worsening disease, verified by clinical follow-up between 6 and 25 months after the nuclear studies (median: 12 months). An MIBI baseline study was positive in 21 of 24 patients (87%), whereas the dobutamine study was positive in all patients. Thirty-five abnormal foci were seen on baseline MIBI studies and 43 on dobutamine scans (1.46 +/- 1.02 vs. 1.79 +/- 0.88, mean +/- SD, respectively, P = 0.043). Dobutamine PT/T ratios were significantly higher than those from the baseline study (1.49 +/- 0.30 vs. 1.38 +/- 0.28, mean +/- SD, respectively, P = 0.0002, n = 43). We concluded that low-dose dobutamine Tc-99m MIBI scintigraphy has the potential of enhancing tracer uptake and retention in patients with SHP.

99mTc-Glucarato como posible trazador de lesiones de cáncer broncopulmonar / 99mTc-Glucarate as a potential novel tracer of lung cancer lesions

El cáncer broncopulmonar (CBP) es la primera causa de muerte por cáncer en el mundo. El CBP a células no pequeñas (CBPCNP) representa el 80 por ciento de la patología neoplásica pulmonar, presentándose frecuentemente al diagnóstico como localmente avanzando o metastásico. Dos tercios se presentan en etapa avanzada, inoperable, integrando la quimioterapia (QT) el tratamiento. Responden favorablemente 30 por ciento de dichos pacientes; los restantes recibirán agentes antineoplásicos sin beneficio terapéutico pero con sus efectos adversos. Ante dicha situación sería de gran relevancia clínica poder contar con una técnica funcional que permitiera evaluar la respuesta a la terapia oncoespecífica. Por tal motivo, nuestro grupo ha desarrollado un protocolo clínico para investigar la capacidad del 99mTc-Glucarato en la evaluación precoz de la respuesta a la QT en este grupo de pacientes. Para ello, es necesario demostrar previamente que las lesiones primarias y secundarias del CBPCNP pueden acumular este trazador. La presente nota clínica describe por vez primera en la literatura indexada la capacidad del 99mTc-Glucarato como marcador funcional de lesiones primarias y metastásicas del CBPCNP.