Patterns of extension of gastrointestinal stromal tumors (GIST) treated with imatinib (Gleevec®) by 18F-FDG PET/CT.

BACKGROUND AND AIM: currently it is recognized the usefulness of 18F-FDG PET in assessing response to therapy with imatinib (Gleevec®) in the gastrointestinal tract sarcomas (GIST). To facilitate the follow-up of these studies is important to know the patterns of metastatic spread. The aim of this paper is to describe patterns observed in the 18F-FDG PET/CT. METHOD: retrospective study included 29 patients who underwent 18F-FDG PET/CT after being diagnosed with unresectable or metastatic GIST. In total, 87 PET/CT studies were performed (1-6 controls per patient) with a mean time of follow-up 6-36 months. We analyzed the location of the lesions evidenced in PET, CT and fusion. Images were evaluated visually and semiquantitatively (SUV). In cases in which has been considered necessary, additional images have been undertaken: PET delayed imaging, intravenous contrast CT and inspiratory chest CT. RESULTS: the most common primary site was the stomach (41%), small bowel (35%), and rectum (24%). Significant changes in the location of metastatic disease between pre-treatment and the monitoring were observed, with the appearance of more extra-abdominal disease. CONCLUSIONS: individualization of protocol studies and interpretation of PET, CT and fused images were required for evaluation of treatment response to imatinib. Hybrid 18F-FDG PET/CT provides an accurate determination of the extent of GIST. While the most common metastatic site is the liver and peritoneum, in the following cases are common extra-abdominal disease.

Patrones de extensión de los tumores del estroma gastrointestinal (GIST) tratados con imatinib (Gleevec®) mediante PET/TC con 18F-FDG / Patterns of extension of gastrointestinal stromal tumors (GIST) treated with imatinib (Gleevec)® by 18F-FDG PET/CT

Introducción y objetivo: actualmente está reconocida la utilidad de la 18F-FDG-PET en la evaluación de la respuesta a la terapia con imatinib (Gleevec®) en los sarcomas del tracto gastrointestinal (GIST). Para facilitar la valoración comparativa de estos estudios es importante conocer sus patrones de diseminación metastásica. El objetivo de este trabajo es describir estos patrones evidenciados en la 18F-FDG-PET/TC. Método: estudio retrospectivo de 29 pacientes a los que se les realizó una 18F-FDG-PET/TC, tras haber sido diagnosticados de un GIST irresecable o metastásico. En total se realizaron 87 estudios PET/TC (1-6 controles por paciente) con tiempo medio posterior de seguimiento entre 6-36 meses. Se analizó la localización de las lesiones evidenciadas en las imágenes PET, TC y de fusión, y se valoraron las imágenes de forma visual y semicuantitativa (SUV). En aquellos casos en los que para la valoración de las imágenes se ha considerado necesario se han realizado exploraciones adicionales: imágenes tardías PET, TC con contraste endovenoso y TC inspiratorio torácico. Resultados: la localización primaria más frecuente fue la gástrica (41%), el intestino delgado (35%) y el recto (24%). Son muy significativos los cambios en la localización de la enfermedad metastásica entre el estudio pre-tratamiento y los controles de seguimiento, observándose evolutivamente la aparición de mayor enfermedad extra-abdominal. Conclusiones: para la evaluación de la respuesta a la terapia es necesaria la valoración de las imágenes integradas y la individualización del protocolo de la exploración. La exploración híbrida PET/TC proporciona una precisa determinación de la extensión del GIST. Si bien la localización metastásica más habitual es el hígado y el peritoneo, en el seguimiento son frecuentes los casos con enfermedad extra-abdominal(AU)

Background and aim: currently it is recognized the usefulness of 18F-FDG PET in assessing response to therapy with imatinib (Gleevec ®) in the gastrointestinal tract sarcomas (GIST). To facilitate the follow-up of these studies is important to know the patterns of metastatic spread. The aim of this paper is to describe patterns observed in the 18F-FDG PET/CT. Method: retrospective study included 29 patients who underwent 18F-FDG PET/CT after being diagnosed with unresectable or metastatic GIST. In total, 87 PET/CT studies were performed (1-6 controls per patient) with a mean time of follow-up 6-36 months. We analyzed the location of the lesions evidenced in PET, CT and fusion. Images were evaluated visually and semiquantitatively (SUV). In cases in which has been considered necessary, additional images have been undertaken: PET delayed imaging, intravenous contrast CT and inspiratory chest CT. Results: the most common primary site was the stomach (41%), small bowel (35%), and rectum (24%). Significant changes in the location of metastatic disease between pre-treatment and the monitoring were observed, with the appearance of more extra-abdominal disease. Conclusions: individualization of protocol studies and interpretation of PET, CT and fused images were required for evaluation of treatment response to imatinib. Hybrid 18F-FDG PET/CT provides an accurate determination of the extent of GIST. While the most common metastatic site is the liver and peritoneum, in the following cases are common extra-abdominal disease(AU)

Prognostic performance of quantitative PET tools for stratification of patients with ischemic cardiomyopathy undergoing myocardial viability assessment.

OBJECTIVES: This study was performed to determine the prognostic performance of quantitative PET tools in the stratification of patients with ischemic cardiomyopathy undergoing myocardial viability assessment. METHODS: We applied four different quantitative tools to 104 consecutive patients with coronary artery disease and previous myocardial infarction who had undergone rest Rb/gated F-fluorodeoxyglucose (FDG) PET, to assess myocardial viability for potential revascularization. One of these tools was based on the FDG study alone and the other three tools assessed the extent of match/mismatch defects using FDG in comparison with a perfusion reference database. The four quantitative tools used in this research to define viability were (i) FDG alone, which calculates the percentage of left ventricular myocardium (LVM) that is above the 50% of the maximum LVM FDG counts, (ii) low flow match/mismatch, which determines the area with a 5% increase in normalized FDG counts in relation to defined resting perfusion defects as compared with a reference database, (iii) all regions match/mismatch, which computes the area with a 10% increase in normalized FDG counts in relation to the left ventricle resting perfusion distribution, and (iv) percentage max FDG match/mismatch, which defines the area with FDG uptake greater than 60% of the maximum LVM FDG counts within defined perfusion defects as determined by the reference database. The primary endpoint for this analysis was cardiac death. RESULTS: During the follow-up period (22+/-14 months), 19 patients (18%) died; in 17 of these the cause of death was cardiac. Using univariate analysis, none of the methods were predictive of cardiac death. Receiver operating characteristic analysis defined the optimal thresholds for the extent of myocardial viability for the four tools in the prediction of cardiac death: FDG alone=20%, low flow match/mismatch=15%, all regions match/mismatch=35%, and percentage max FDG match/mismatch=20%. A censored survival analysis using a Kaplan-Meier method showed a statistically significant difference between patients with cardiac death and those with no cardiac death using only the low flow match/mismatch (hazard ratio=0.29, P=0.01) and percentage max FDG match/mismatch criteria (hazard ratio=0.23, P=0.005) tools. CONCLUSION: The low flow match/mismatch and percentage max FDG match/mismatch quantitative PET tools are useful for prognostic stratification of patients with ischemic cardiomyopathy undergoing myocardial viability assessment.

Intravenous furosemide injection during 18F-FDG PET acquisition.

UNLABELLED: Urinary-system elimination of (18)F-FDG can be mistaken for pathologic uptake. Furosemide helps eliminate this artifact. Unnecessary administration should be avoided. Our approach obviates furosemide administration and other invasive procedures in many cases. METHODS: Thirty-seven cancer patients referred for PET to evaluate treatment response or suspected recurrence were prospectively studied using whole-body scanning, with (18)F-FDG injected via dorsal hand catheter beforehand. The catheter was left in place to enable injection of furosemide while the patient was inside the scanner. After abdominopelvic scanning, physicians evaluated the need to inject furosemide. Thirty minutes after furosemide injection, another abdominopelvic scan was obtained to detect postinjection urinary tract changes. RESULTS: Postfurosemide images showed effects due to physiologic elimination in 24 patients (64.9%), of whom 11 patients (45.8%) had more than one inconclusive prefurosemide finding. In 13 patients (35.1%), delayed images confirmed persistent lymph node uptake, including 3 patients (23.1%) with 1 lesion. CONCLUSION: Furosemide injection during scanning reduces artifacts, shortens examinations, and helps avoid invasive procedures.

The diagnostic possibilities of positron emission tomography (PET): applications in oral and maxillofacial buccal oncology.

The principles of positron emission tomography (PET), recently introduced as a diagnostic procedure into the health sciences, are described. The principle clinical applications apply to a particular group of specialties: cardiology, neurology, psychiatry, and above all oncology. Positron emission tomography is a non-invasive diagnostic imaging technique with clinical applications. It is an excellent tool for the study of the stage and possible malignancy of tumors of head and neck, the detection of otherwise clinically indeterminate metastases and lymphadenopathies, and likewise for the diagnosis of relapses. The only tracer with any practical clinical application is fluor-desoxyglucosa-F18 (FDG). PET detects the intense accumulation of FDG produced in malignant tumors due to the increased glycolytic rate of the neoplastic cells. With the introduction of hybrid systems that combine computerized tomography or magnetic resonance with positron emission tomography, important advances are being made in the diagnosis and follow-up of oncologic pathology of head and neck.

Posibilidades diagnósticas de la Tomografía por Emisión de Positrones (PET): Aplicaciones en la patología oncológica bucal y maxilofacial / The diagnostic possibilities of Positron Emission Tomography (PET)

Se describen los principios de la tomografía por emisión de positrones (PET) como procedimiento diagnóstico de reciente introducción en el campo de las Ciencias de la Salud. Las aplicaciones clínicas principales se dan en un grupo concreto de especialidades: la cardiología, neurología, psiquiatría y sobre todo la oncología.La tomografía por emisión de positrones es una técnica de diagnóstico por la imagen no invasiva de uso clínico. Se trata de una excelente herramienta para el estudio de la estadificación y la posible malignización de los tumores de cabeza y cuello, la detección de metástasis y linfoadenopatías no valorables clínicamente, así como para el diagnóstico de recidivas tumorales. El único trazador que tiene aplicación clínica es la fluor-desoxiglucosa-F18 o FDG. La PET detecta la intensa acumulación de FDG que se produce en los tumores malignos, debido al mayor índice glicolítico que tienen las células neoplásicas.Con la introducción de sistemas híbridos que combinan la tomografía computadorizada o la resonancia magnética con la tomografía por emisión de positrones, se está produciendo un importante avance en el diagnóstico y el seguimiento de la patología oncológica de cabeza y cuello

The principles of positron emission tomography (PET), recently introduced as a diagnostic procedure into the health sciences, are described. The principle clinical applications apply to a particular group of specialties: cardiology, neurology, psychiatry, and above all oncology. ;;Positron emission tomography is a non-invasive diagnostic imaging technique with clinical applications. It is an excellent tool for the study of the stage and possible malignancy of tumors of head and neck, the detection of otherwise clinically indeterminate metastases and lymphadenopathies, and likewise for the diagnosis of relapses. The only tracer with any practical clinical application is fluor-desoxyglucosa-F18 (FDG). PET detects the intense accumulation of FDG produced in malignant tumors due to the increased glycolytic rate of the neoplastic cells. ;;With the introduction of hybrid systems that combine computerized tomography or magnetic resonance with positron emission tomography, important advances are being made in the diagnosis and follow-up of oncologic pathology of head and neck

Incremental prognostic value of left ventricular function by myocardial ECG-gated FDG PET imaging in patients with ischemic cardiomyopathy.

BACKGROUND: The purpose of this study was to determine the independent value of left ventricular (LV) functional parameters derived from gated fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) to predict prognosis in patients with ischemic cardiomyopathy undergoing myocardial viability assessment. METHODS AND RESULTS: We studied 90 consecutive patients with coronary artery disease and low LV ejection fraction (26% +/- 7%) undergoing gated FDG PET to assess myocardial viability for potential revascularization. The primary endpoint for this analysis was the occurrence of cardiac death, myocardial infarction, or worsening heart failure (HF) to New York Heart Association class IV. During follow-up (22 +/- 14 months), 21 patients had an event (17 died, 4 had myocardial infarctions, and 4 had worsening HF). On Cox regression analysis, the event-free survival rate at 2 years was lower for patients with an end-diastolic volume (EDV) of 260 mL or greater (relative risk, 2.7; P = .014), end-systolic volume (ESV) of 200 mL or greater (relative risk, 2.5; P = .021), and LV mass of 143 g or greater (relative risk, 1.6; P = .009). In a risk-adjusted model, EDV (chi 2 = 68, P < .0001) and ESV (chi 2 = 75, P = .035) added a significant amount in the estimation of events over the perfusion-FDG mismatch pattern (chi 2 = 40, P < .001). In a stratified Cox model, patients with PET mismatch, LV ejection fraction lower than 25%, and EDV of 260 mL or greater had the lowest survival rate (P = .006). These patients showed an apparent survival benefit with revascularization but without an improvement in HF symptoms. CONCLUSION: LV functional parameters determined by gated FDG PET have incremental prognostic value over viability information in patients with ischemic cardiomyopathy. Our data suggest that patients with residual viability and advanced cardiac remodeling are at high clinical risk. In these patients the apparent survival benefit of revascularization may not be associated with a measurable improvement in HF symptoms.

Regional wall motion and wall thickening visual scores from gated SPECT in anterior and infero-lateral myocardial infarctions.

BACKGROUND: The relationship between the visual scores for wall motion (WM) and wall thickening (WT) of different left ventricular regions in patients with anterior and infero-lateral myocardial infarctions was evaluated using gated SPECT. METHODS: Ninety consecutive patients (79 men and 11 women; mean age 56 +/- 9 years) with previous myocardial infarction (33 anterior and 57 infero-lateral) were included. Left ventricular volumes and ejection fractions (EFs) were calculated from quantitative rest gated SPECT 99mTc tetrofosmin images by using the QGS automatic algorithm. Global and regional (anterior, septal, inferior and lateral) wall motion and wall thickening scores were calculated by consensus of three experienced observers. RESULTS: The correlation between EFs and wall motion and wall thickening scores was better for WM scores in anterior (r=0.904, P<0.0001) than infero-lateral infarctions (r=0.674, P<0.0001). Correlation between wall motion and wall thickening scores was also better for anterior (r=0.898, P<0.0001) than for infero-lateral infarctions (r=0.750, P<0.0001). Except in septal regions, WT scores of the different regions were higher than WM scores (P<0.05) but the statistical significance was higher (P<0.001) in inferior and lateral regions of infero-lateral infarctions. CONCLUSION: Visual global wall motion and wall thickening scores obtained by gated SPECT showed good correlation between them and with the EF, but differences were observed between regional wall motion and wall thickening, especially in inferior and lateral regions of patients with infero-lateral infarctions.

[Evolution of systolic function and myocardial perfusion, evaluated by gated-SPECT, in the first year after acute myocardial infarction]. / Evolución de la función sistólica y de la perfusión micárdica valorada mediante gated-SPECT durante el primer año despuésde un infarto agudo de miocardio.

INTRODUCTION AND OBJECTIVES: Systolic function and myocardial perfusion are evaluated before hospital discharge and can change during follow-up. The purpose of this study was to evaluate these parameters by gated-SPECT in the first year after acute myocardial infarction. PATIENTS AND METHOD: We studied 74 consecutive patients with a first uncomplicated acute myocardial infarction (49 infero-lateral and 25 anterior) by stress-rest 99mTc-tetrofosmin and rest-gated-SPECT before hospital discharge (6-8 days after admission) and one year after myocardial infarction. RESULTS: The ejection fraction (EF) increased > 5% in 51% of infero-lateral infarcts and 28% of non-revascularized anterior infarcts. EF increased significantly (48.4 8% to 54.6 8.7%; p < 0.0001, mean difference: 6.2; 95% IC, 2.8-9.5) and systolic volume decreased (51.3 19.2 ml to 44.3 19.4 ml; p = 0.001; mean diff.: 7.67; 95% IC, 1.5-13.8) in infero-lateral infarctions. The rest perfusion index in the necrotic region improved (2.3 0.57 to 2.17 0.58; p = 0.004; mean diff.: 0.18; 95% IC, 0.003-0.36) in infero-lateral infarcts and the ischemia index remained unchanged between the first and second studies. CONCLUSIONS: Left ventricular systolic function can change during the first year of evolution, a significant improvement being seen in infero-lateral infarctions. The ejection fraction increased > 5% in half of these patients, as opposed to only a quarter of anterior infarctions. This improvement was associated to increased myocardial perfusion at rest.

Evolución de la función sistólica y de la perfusión miocárdica valoradas mediante gated-SPECT durante el primer año después de un infarto agudo de miocardio / Evolution of systolic function and myocardial perfusion, evaluated by Gated-SPECT, in the first year after acute myocardial infarction

Introducción y objetivos. La función sistólica ventricular izquierda y la perfusión miocárdica pueden experimentar cambios durante el seguimiento y la evolución de un infarto agudo de miocardio. El objetivo de este estudio es su valoración mediante gated-SPECT. Pacientes y método. Se ha estudiado a 74 pacientes consecutivos con un primer infarto agudo de miocardio no complicado (49 inferolaterales y 25 anteriores) mediante 99m Tc-tetrofosmina de esfuerzo-reposo y gatedSPECT de reposo antes del alta hospitalaria y al año de evolución. Resultados. Entre el primer y el segundo estudios, la fracción de eyección aumentó > 5 por ciento en un 51 por ciento de los infartos inferolaterales y en un 28 por ciento de los infartos anteriores no revascularizados. El aumento de la FE (de 48,4 ñ 8 por ciento a 54,6 ñ 8,7 por ciento; p < 0,0001; diferencia media, 6,2; IC del 95 por ciento, 2,8-9,5) y el descenso del volumen sistólico (de 51,3 ñ 19,2 ml a 44,3 ñ 19,4 ml; p = 0,001; diferencia media, 7,67; IC del 95 por ciento, 1,5-13,8) alcanzaron valores estadísticamente significativos en los infartos inferolaterales. Los índices de perfusión en reposo en la región del infarto mejoraron entre los dos estudios en los infartos inferiores (de 2,3 ñ 0,57 a 2,17 ñ 0,58; p = 0,004; diferencia media, 0,18; IC del 95 por ciento, 0,003-0,36), sin cambios en los índices de isquemia. Conclusiones. La función sistólica ventricular izquierda puede cambiar durante el primer año de evolución, mejorando especialmente en los infartos inferolaterales. En la mitad de éstos, pero sólo en una cuarta parte de los anteriores, la fracción de eyección aumentó más de un 5 por ciento entre el primer y el segundo estudios. Esta mejoría se asoció a un incremento de la perfusión miocárdica en reposo (AU)