RESUMEN
OBJECTIVE: In myocardial perfusion single-photon emission computed tomography (SPECT), abdominal activity often interferes with the evaluation of perfusion in the inferior wall, especially after pharmacological stress. In this randomized study, we examined the effect of carbonated water intake versus still water intake on the quality of images obtained during myocardial perfusion images (MPI) studies. METHODS: A total of 467 MIBI studies were randomized into a carbonated water group and a water group. The presence of intestinal activity adjacent to the inferior wall was evaluated by two observers. Furthermore, a semi-quantitative analysis was performed in the adenosine subgroup, using a count ratio of the inferior myocardial wall and adjacent abdominal activity. RESULTS: The need for repeated SPECT in the adenosine studies was 5.3% in the carbonated water group versus 19.4% in the still water group (p = 0.019). The inferior wall-to-abdomen count ratio was significantly higher in the carbonated water group compared to the still water group (2.11 ± 1.00 vs. 1.72 ± 0.73, p < 0.001). The effect of carbonated water during rest and after exercise was not significant. CONCLUSIONS: This randomized study showed that carbonated water significantly reduced the interference of extra-cardiac activity in adenosine SPECT MPI.
Asunto(s)
Agua Carbonatada , Imagen de Perfusión Miocárdica , Tomografía Computarizada de Emisión de Fotón Único , Adenosina/farmacología , Anciano , Artefactos , Ejercicio Físico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estrés Fisiológico/efectos de los fármacosRESUMEN
With increasing age, there may be a decrease in femoral blood flow. In some patients, this may result in local ischaemia, which subsequently may lead to local degenerative changes. Consequently, bone blood flow may play an important role in the aetiology of osteoarthritis of the hip. Little is known about bone blood flow in the femoral head of patients with advanced hip osteoarthritis. The purpose of this study was to evaluate bone blood flow and metabolism in vivo in patients with osteoarthritis of the hip. Ten patients with symptomatic osteoarthritis of the hip were enrolled prospectively. Femoral bone blood flow and metabolism were measured using positron emission tomography together with H2(15)O and [(18)F]fluoride, respectively. Blood flow was 0.054 ± 0.032 mL cm(-3) min(-1) and 0.041 ± 0.012 mL cm(-3) min(-1) in symptomatic and contralateral femoral heads, respectively (p = 0.435). The net flux of fluoride from plasma to bone mineral (K i ) was significantly (p = 0.027) higher in the femoral head of the osteoarthritic hip (0.022 ± 0.012 mL cm(-3) min(-1)) than in that of the contralateral hip (0.007 ± 0.005 mL cm(-3) min(-1)). This study showed significant increase in bone metabolism in the proximal femur of patients with symptomatic osteoarthritis of the hip joint. There was no evidence of decreased blood flow.
Asunto(s)
Cabeza Femoral/irrigación sanguínea , Cabeza Femoral/metabolismo , Osteoartritis de la Cadera/fisiopatología , Flujo Sanguíneo Regional/fisiología , Anciano , Anciano de 80 o más Años , Densidad Ósea/fisiología , Femenino , Cabeza Femoral/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Cadera/diagnóstico por imagen , Osteoartritis de la Cadera/metabolismo , Radiografía , CintigrafíaRESUMEN
PURPOSE: The aim of this study was to investigate the effect of positron range on visualization and quantification in (18)F, (68)Ga and (124)I positron emission tomography (PET)/CT of lung-like tissue. METHODS: Different sources were measured in air, in lung-equivalent foams and in water, using a clinical PET/CT and a microPET system. Intensity profiles and curves with the cumulative number of annihilations were derived and numerically characterized. RESULTS: (68)Ga and (124)I gave similar results. Their intensity profiles in lung-like foam had a peak similar to that for (18)F, and tails of very low intensity, but extending over distances of centimetres and containing a large fraction of all annihilations. For 90% recovery, volumes of interest with diameters up to 50 mm were required, and recovery within the 10% intensity isocontour was as low as 30%. In contrast, tailing was minor for (18)F. CONCLUSION: Lung lesions containing (18)F, (68)Ga or (124)I will be visualized similarly, and at least as sharp as in soft tissue. Nevertheless, for quantification of (68)Ga and (124)I large volumes of interest are needed for complete activity recovery. For clinical studies containing noise and background, new quantification approaches may have to be developed.
Asunto(s)
Electrones , Radioisótopos de Flúor , Pulmón/diagnóstico por imagen , Fantasmas de Imagen , Tomografía de Emisión de Positrones/instrumentación , Tomografía Computarizada por Rayos X/instrumentación , Agar , Radioisótopos de Galio , Humanos , Procesamiento de Imagen Asistido por Computador , Radioisótopos de Yodo , Jeringas , AguaRESUMEN
BACKGROUND AND PURPOSE: This study's objective was to compare (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG PET), CT, and MRI of carotid plaque assessment. MATERIALS AND METHODS: Fifty patients with symptomatic carotid atherosclerosis underwent (18)F-FDG PET/CT and MRI. Correlations and agreement between imaging findings were assessed by Spearman and Pearson rank correlation tests, t tests, and Bland-Altman plots. RESULTS: Spearman rho between plaque (18)F-FDG standard uptake values and CT/MRI findings varied from -0.088 to 0.385. Maximum standard uptake value was significantly larger in plaques with intraplaque hemorrhage (1.56 vs 1.47; P=0.032). Standard uptake values did not significantly differ between plaques with an intact and thick fibrous cap and plaques with a thin or ruptured fibrous cap on MRI. (1.21 vs 1.23; P=0.323; and 1.45 vs 1.54; P=0.727). Pearson rho between CT and MRI measurements varied from 0.554 to 0.794 (P<0.001). For lipid-rich necrotic core volume, the CT-MRI correlation was stronger in mildly (
Asunto(s)
Estenosis Carotídea/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Imagen por Resonancia Magnética/estadística & datos numéricos , Tomografía de Emisión de Positrones/estadística & datos numéricos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Calcinosis/diagnóstico por imagen , Calcinosis/patología , Arterias Carótidas/diagnóstico por imagen , Arterias Carótidas/patología , Estenosis Carotídea/patología , Femenino , Fibrosis/diagnóstico por imagen , Fibrosis/patología , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Lípidos/análisis , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Tomografía de Emisión de Positrones/métodos , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Estadística como Asunto , Tomografía Computarizada por Rayos X/métodosRESUMEN
UNLABELLED: The presence of (124)I in tissue near the trachea can cause a phenomenon that might be called shine-through. The effect is due to high-energy positrons that cross the air-filled trachea and annihilate at the opposite tracheal wall, incorrectly suggesting uptake at that location. METHODS: We investigated shine-through using (124)I, (68)Ga, and (18)F PET/CT scans of a neck phantom. Additionally, we evaluated (124)I studies of 29 patients with differentiated thyroid cancer who underwent imaging for postsurgical staging. RESULTS: In the phantom studies with a 0.1-mL (124)I source, the relative intensity of shine-through decreased from 7% to nearly zero when the thickness of the positron-stopping layer was increased from 0.3 to 3.85 mm. In patients, shine-through was observed in 5 of the 29 studies, with intensities between 0.7% and 14%. CONCLUSION: Shine-through appears rather common in differentiated thyroid cancer. Recognition is important for identification of real lesions, calculation of uptake, and dosimetry.
Asunto(s)
Radioisótopos de Yodo , Tomografía de Emisión de Positrones/métodos , Tomografía Computarizada por Rayos X/métodos , Tráquea/diagnóstico por imagen , Artefactos , Humanos , Fantasmas de Imagen , Neoplasias de la Tiroides/diagnóstico por imagenRESUMEN
PURPOSE: To evaluate bone blood flow and bone formation in patients after total hip revision surgery with impacted bone grafting using H2 15O and [18F]fluoride positron emission tomography (PET). PROCEDURES: To asses bone blood flow and bone metabolism in bone allograft after impaction grafting, four patients treated with total hip revision surgery were enrolled prospectively in this study. Six patients scheduled for primary hip arthroplasties were included as a control group. The study protocol consisted of three H2 15O and [18F]fluoride PET scans in each patient. RESULTS: Bone blood flow increased significantly compared to the preoperative state in patients treated for primary hip arthroplasty. In patients undergoing revision surgery, bone blood flow was twofold to threefold higher compared to the preoperative state, but did not reach significance. Bone metabolism in patients undergoing revision was threefold higher 2 weeks postoperatively compared to the primary hip group. We found a significant correlation between Ki and bone blood flow. CONCLUSIONS: Allogeneic bone grafts induce a higher rate of local periprosthetic bone formation compared to periprosthetic bone formation after a primary total hip placement. In vivo coupling between bone blood flow and bone metabolism suggests that bone metabolism in allogeneic bone grafts may partly rely on bone blood flow adaptations.
Asunto(s)
Huesos/metabolismo , Luxación de la Cadera/diagnóstico por imagen , Luxación de la Cadera/metabolismo , Prótesis de Cadera , Tomografía de Emisión de Positrones/métodos , Anciano , Deuterio , Femenino , Radioisótopos de Flúor , Luxación de la Cadera/cirugía , Humanos , Masculino , Radioisótopos de Oxígeno , Proyectos Piloto , Resultado del TratamientoRESUMEN
AIMS: On the basis of an MRI study it has been suggested that subendocardial hypoperfusion is present in patients with cardiac syndrome X. However, further work is required to test whether these findings can be generalized. METHODS AND RESULTS: MRI was used to visually and semi-quantitatively assess subendocardial and subepicardial perfusion, at rest and during an infusion of adenosine, in 20 patients with angina pectoris and normal coronary angiograms. A myocardial perfusion index (MPI) was calculated using the normalized upslope of myocardial signal enhancement. An index for myocardial perfusion reserve (MPRI) was calculated by dividing the MPI values at maximal vasodilatation by the values at rest. The MPI in our study population increased significantly during adenosine infusion in both the subendocardium (from 0.091 +/- 0.020 to 0.143 +/- 0.030; P < 0.001) and the subepicardium (from 0.074 +/- 0.017 to 0.135 +/- 0.03; P < 0.001). The overall MPRI was 1.83 +/- 0.50. CONCLUSION: The results show that patients with chest pain and normal coronary angiograms had significant perfusion responses to adenosine in both the subendocardium and subepicardium. In the present study we found no evidence for subendocardial hypoperfusion in these patients.
Asunto(s)
Dolor en el Pecho/etiología , Isquemia Miocárdica/complicaciones , Presión Sanguínea/fisiología , Dolor en el Pecho/fisiopatología , Angiografía Coronaria , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Angiografía por Resonancia Magnética , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/fisiopatología , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
PURPOSE: To perform a systematic review and meta-analysis to determine the diagnostic accuracy of attenuation-corrected (AC) vs. nonattenuation-corrected (NAC) 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) in oncological patients. PROCEDURES: Following a comprehensive search of the literature, two reviewers independently assessed the methodological quality of eligible studies. The diagnostic value of AC was studied through its sensitivity/specificity compared to histology, and by comparing the relative lesion detection rate reported with NAC-PET vs. AC, for full-ring and dual-head coincidence PET (FR- and DH-PET, respectively). RESULTS: Twelve studies were included. For FR-PET, the pooled sensitivity/specificity on a patient basis was 64/97% for AC and 62/99% for NAC, respectively. Pooled lesion detection with NAC vs. AC was 98% [95% confidence interval (95% CI): 96-99%, n = 1,012 lesions] for FR-PET, and 88% (95% CI:81-94%, n = 288 lesions) for DH-PET. CONCLUSIONS: Findings suggest similar sensitivity/specificity and lesion detection for NAC vs. AC FR-PET and significantly higher lesion detection for NAC vs. AC DH-PET.
Asunto(s)
Fluorodesoxiglucosa F18 , Neoplasias/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Radiofármacos , Humanos , Neoplasias/patología , Tomografía de Emisión de Positrones/estadística & datos numéricos , Sensibilidad y EspecificidadRESUMEN
UNLABELLED: Radiation dosimetry of thyroid cancer therapy with 131I can be performed by coadministration of 124I followed by longitudinal PET scans over several days. The photons emitted by 131I may affect PET image quality. The aim of this study was to assess the influence of large amounts of 131I on PET image quality and accuracy with various acquisition settings. METHODS: Noise equivalent count (NEC) rates of 124I only were measured with a standard clinical PET scanner. Apart from the standard 350- to 650-keV energy window, 425- to 650-keV and 460- to 562-keV windows were used and data were acquired both with (2-dimensional) and without (3-dimensional [3D]) septa. A phantom containing 6 hot spheres, filled with a combination of 131I and 124I and with a sphere-to-background ratio of 18:1, was scanned repeatedly with energy window settings as indicated and emission and transmission scan durations of 7 and 3 min, respectively. NEC rates were calculated and compared with those measured with the phantom filled with only 124I. Sphere-to-background ratios in the reconstructed images were determined. One patient with known metastatic thyroid cancer was scanned using energy window settings and scan times as indicated 3 and 6 d after administration of 5.5 GBq of 131I and 75 MBq of 124I. RESULTS: The highest 124I-only NEC rates were obtained using a 425- to 650-keV energy window in 3D mode. In the presence of (131)I, the settings giving the highest NEC rate and contrast were 425-650 keV and 460-562 keV in 3D mode, with the clinical scans giving the highest quality images with the same settings. CONCLUSION: Acquisition in 3D mode with a 425- to 650-keV or 460- to 562-keV window leads to the highest image quality and contrast when imaging 124I in the presence of large amounts of 131I using a standard clinical PET scanner.
Asunto(s)
Radioisótopos de Yodo/uso terapéutico , Tomografía de Emisión de Positrones/métodos , Radiometría/métodos , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/radioterapia , Anciano , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Metástasis de la Neoplasia , Fantasmas de Imagen , Fotones , Tomografía de Emisión de Positrones/instrumentación , Radiofármacos/uso terapéutico , Factores de Tiempo , Imagen de Cuerpo EnteroRESUMEN
BACKGROUND: Plain radiography, subtraction arthrography, nuclear arthrography, and bone scintigraphy are imaging techniques commonly used to identify aseptic femoral component loosening. Controversy exists about the relative utility of these techniques. PATIENTS AND METHODS: We evaluated the diagnostic accuracy and interobserver reliability of the four techniques in 78 consecutive patients (mean age 70 years, range 29-88 years) referred for evaluation of their femoral hip prostheses. The standard evaluation protocol consisted of plain radiography followed by subtraction arthrography, nuclear arthrography, and bone scintigraphy. Surgery or the subsequent clinical course of the patient was used as gold standard. RESULTS: Overall, plain radiography had a sensitivity and specificity of 81 and 74%, respectively. Subtraction arthrography had a sensitivity of 47% and a specificity of 78%. Nuclear arthrography had a sensitivity of 69% and a specificity of 76%, and bone scintigraphy had a sensitivity of 88% with a specificity of 50%. CONCLUSION: We found considerable interobserver variability in all four techniques. Multivariate regression analysis revealed that bone scintigraphy and nuclear arthrography together made a significant contribution to the diagnosis when used in combination with plain radiography and are, when plain radiography is inconclusive, useful additional diagnostic techniques for the detection of femoral component loosening.
Asunto(s)
Artrografía/métodos , Articulación de la Cadera/diagnóstico por imagen , Prótesis de Cadera , Adulto , Anciano , Anciano de 80 o más Años , Artroplastia de Reemplazo de Cadera , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Cintigrafía , Radiofármacos , Estudios Retrospectivos , Sensibilidad y Especificidad , Medronato de Tecnecio Tc 99mRESUMEN
PURPOSE: We investigated whether application of positron emission tomography (PET) immediately after first presentation might simplify staging while maintaining accuracy, as compared with traditional strategy in routine clinical setting. METHODS: At first presentation, patients with a provisional diagnosis of lung cancer without overt dissemination were randomly assigned to traditional work-up (TWU) according to international guidelines or early PET followed by histologic/cytologic verification of lesions, or imaging and follow-up. Patients with [18F] fluorodeoxyglucose (18FDG) -avid, noncentral tumors without suspicion of mediastinal or distant metastases on PET proceeded directly to thoracotomy. Follow-up in presumed benign lesions was at least 12 months. In patients treated with surgery or neoadjuvant therapy, the quality of staging was measured by comparing the clinical stage to the final stage (combination of peroperative staging and 6 months of follow-up). To investigate test substitution, we analyzed the number of (non)invasive tests to achieve clinical TNM staging, and its associated costs. RESULTS: Between 1999 and 2001, 465 patients (233 TWU, 232 PET) were enrolled at 22 hospitals. The mean (standard deviation) number of procedures to finalize staging was equal in the TWU arm and the PET arm: 7.9 (2.0) v 7.9 (1.9), P = .90, respectively. Mediastinoscopies occurred significantly less often in the PET arm. Agreement between clinical and final stage was good in both arms (kappa = .85 v .78; P = .07). Costs did not differ significantly. CONCLUSION: Up-front 18FDG-PET in patients with (suspected) lung cancer does not reduce the overall number of diagnostic test, but it maintains quality of TNM staging with the use of less invasive surgery.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Neoplasias Pulmonares/diagnóstico por imagen , Estadificación de Neoplasias/métodos , Anciano , Carcinoma de Pulmón de Células no Pequeñas/terapia , Femenino , Fluorodesoxiglucosa F18 , Costos de la Atención en Salud , Humanos , Neoplasias Pulmonares/terapia , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Estadificación de Neoplasias/economía , Estadificación de Neoplasias/normas , Cintigrafía , Radiofármacos , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
OBJECTIVE: To summarize and compare the diagnostic accuracy of contrast and subtraction arthrography in the assessment of aseptic loosening of total hip arthroplasties. DESIGN: This meta-analysis was performed using methods described by the Cochrane Methods Group on Systematic Reviews of Screening and Diagnostic Tests. We included original, English-language papers published between January 1975 to October 2004 that examined contrast-enhanced arthrography with or without subtraction for diagnosis of loosening of total hip prostheses. A qualitative and quantitative analysis was performed by two investigators. RESULTS: With regard to the acetabular component, pooled sensitivity and specificity for contrast arthrography was 70% (95% confidence interval, 52-84) and 74% (95% CI, 53-87), respectively. Subtraction arthrography had a significantly higher sensitivity of 89% (95% CI, 84-93) (p=0.01), with a similar specificity of 76% (95% CI, 68-82). For the femoral component, pooled sensitivity and specificity for contrast arthrography were 63% (95% CI, 53-72) and 78% (95% CI, 68-86). Pooled estimates for subtraction arthrography revealed a significantly higher sensitivity of 86% (95% CI, 74-93) (p=0.003). Specificity was 85% (95% CI, 77-91) and was similar to the data of contrast arthrography (p=0.23). CONCLUSION: Using the present data we found that the subtraction arthrography is a sensitive technique for detection of loosening of total hip prostheses, offering added value over contrast arthrography, especially for evaluation of the femoral component.
Asunto(s)
Artrografía/métodos , Medios de Contraste/administración & dosificación , Articulación de la Cadera/diagnóstico por imagen , Prótesis de Cadera , Falla de Prótesis , Técnica de Sustracción , Adulto , Artroplastia de Reemplazo de Cadera/efectos adversos , Humanos , Curva ROC , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: The diagnosis of a loose total hip prosthesis is often established with use of radiographic and nuclear medicine techniques, but there is controversy about the relative utility of plain radiography, subtraction arthrography, nuclear arthrography, and bone scintigraphy. In this retrospective study, we evaluated the sensitivity, specificity, and interobserver reliability of these imaging modalities in patients suspected of having aseptic loosening of the acetabular component. METHODS: From 1994 to 1999, eighty-six consecutive patients with pain after a total hip arthroplasty were evaluated for possible loosening of the components. The imaging evaluation included plain radiography followed by a one-day protocol that included bone scintigraphy, subtraction arthrography, and nuclear arthrography. For this study, two experienced nuclear medicine physicians and two experienced radiologists, all of whom were blinded with respect to the clinical pretest data and the clinical outcome, retrospectively interpreted the diagnostic images. The sensitivity and the specificity of each imaging modality were established by comparing the findings obtained with each technique with those found at surgery or during the subsequent clinical course of the patient. Interobserver variability was determined with the intraclass correlation coefficient. RESULTS: Plain radiography had a sensitivity of 85% (95% confidence interval, 71 to 94) and a specificity of 85% (95% confidence interval, 66 to 96) in detecting aseptic loosening of the acetabular component, but it had only fair interobserver variability (intraclass correlation coefficient, 0.37). For subtraction arthrography, the sensitivity was 72% (95% confidence interval, 57 to 84), the specificity was 70% (95% confidence interval, 50 to 86), and there was good interobserver variability (intraclass correlation coefficient, 0.71). For nuclear arthrography, the sensitivity was 57% (95% confidence interval, 41 to 71), the specificity was 67% (95% confidence interval, 46 to 84), and there was fair interobserver variability (intraclass correlation coefficient, 0.24). For bone scintigraphy, the sensitivity was 83% (95% confidence interval, 69 to 92), the specificity was 67% (95% confidence interval, 46 to 84), and there was moderate interobserver variability (intraclass correlation coefficient, 0.43). CONCLUSIONS: Plain radiography had the highest diagnostic accuracy in the evaluation of aseptic loosening of the acetabular component. The diagnostic accuracy was increased when plain radiography was combined with bone scintigraphy or subtraction arthrography. However, we found considerable interobserver variability in image interpretation, even with experienced radiologists and nuclear medicine physicians.
Asunto(s)
Artroplastia de Reemplazo de Cadera , Articulación de la Cadera/diagnóstico por imagen , Falla de Prótesis , Acetábulo , Adulto , Anciano , Anciano de 80 o más Años , Cementación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Radiografía , Cintigrafía , Sensibilidad y Especificidad , Técnica de SustracciónRESUMEN
Solitary pulmonary nodule (SPN, intraparenchymal lung mass <3 cm) is often a diagnostic challenge. This study was performed to evaluate the diagnostic accuracy of( 18)F-fluorodeoxyglucose positron emission tomography (FDG PET) in radiologically indeterminate SPN < or =10 mm on spiral CT. Between August 1997 and March 2001, we identified all patients with radiologically indeterminate SPNs < or =10 mm who were referred for FDG PET imaging at the VU University Medical Centre. All PET scans were retrospectively reviewed by an experienced nuclear medicine physician. PET was considered positive in cases with at least moderately enhanced focal uptake, and otherwise as negative. Lesions were considered benign on the basis of histology, no growth during 1.5 years or disappearance within at least 6 months. Thirty-five patients with 36 SPNs < or =10 mm in diameter at clinical presentation were identified (one patient had two metachronous lesions). In 13 of 14 malignant nodules and in two of 22 benign nodules, diagnosis was confirmed by histology. Prevalence of malignancy was 39%. PET imaging correctly identified 30 of 36 small lesions. One lesion proved to be false negative on PET (CT: 10 mm), and in five lesions, PET scans proved to be false positive. Specificity was 77% (17/22; 95% CI: 0.55-0.92), sensitivity 93% (13/14; 95% CI: 0.66-1.0), positive predictive value 72% (13/18; 95% CI: 0.46-0.90) and negative predictive value 94% (17/18; 95% CI: 0.73-1.0). This retrospective study suggests that FDG PET imaging could be a useful tool in differentiating benign from malignant SPNs < or =10 mm in diameter at clinical presentation. Such results may help in the design of larger prospective trials with structured clinical work-up.
Asunto(s)
Fluorodesoxiglucosa F18 , Tomografía de Emisión de Positrones/métodos , Nódulo Pulmonar Solitario/diagnóstico por imagen , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Radiofármacos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad , Método Simple Ciego , Nódulo Pulmonar Solitario/diagnósticoRESUMEN
The sentinel node (SN) procedure has been proven to be a valuable technique in the staging and treatment of a number of solid tumours. We evaluated the feasibility of SN biopsy with a laparoscopic gamma probe and dye guidance in 34 patients with clinically localised cervical cancer. After peritumoural injection of 140 MBq 99mTc colloidal albumin, dynamic and late static images were obtained. Just before the laparoscopic procedure, blue dye was injected. Blue and radioactive lymph nodes were excised followed by a regular lymphadenectomy. Lymphoscintigraphy revealed 70 SNs in 50 basins during dynamic imaging and 83 SNs in 63 basins at late imaging. SNs were visualised in 97% of the patients, bilaterally in 30 and unilaterally in three. Seventy-four of the 105 radioactive lymph nodes that were excised laparoscopically were considered to be SNs, 53 being blue as well, and were sent for frozen section. Nine foci that had been seen on scintigraphy could not be found either intraoperatively or in the remaining lymphadenectomy specimen. Four blue nodes were excised in three of five basins that had shown no foci during scintigraphy. In 17 basins of 12 patients, tumour-positive lymph nodes were found. In one of them a micrometastasis was found in the hysterectomy specimen while the lymphadenectomy did not contain any metastases (sensitivity 92%). Based on SN histology, the treatment was altered in nine patients (26%). We conclude that laparoscopic SN biopsy is feasible in cervical cancer and may result in custom-designed treatment strategies with a reduction in morbidity.
Asunto(s)
Laparoscopía/métodos , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/patología , Biopsia del Ganglio Linfático Centinela/métodos , Cirugía Asistida por Computador/métodos , Neoplasias del Cuello Uterino/diagnóstico por imagen , Neoplasias del Cuello Uterino/patología , Adulto , Estudios de Factibilidad , Femenino , Cámaras gamma , Humanos , Metástasis Linfática , Pronóstico , Cintigrafía , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
PURPOSE: To prospectively evaluate the effect of adding whole-body (18)F-2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) to conventional screening for distant metastases in patients with locally advanced breast cancer (LABC). PATIENTS AND METHODS: All women with LABC referred for participation in the LABC Spinoza trial were considered eligible for this study. Patients were included if chest x-ray, bone scan, liver ultrasound, or computed tomography scan performed by the referring physician failed to reveal distant metastases. They underwent whole-body FDG PET scanning before therapy. Patients with subsequently proven distant metastases were switched to alternative forms of chemotherapy, hormonal therapy, or both. RESULTS: Among the 48 patients evaluated with PET, 14 had abnormal FDG uptake, and metastases were suspected in 12. After simple clinical evaluation (plain x-ray, history), 10 sites that were suggestive of abnormality remained. Further work-up revealed that four sites were metastases. Proven false positivity occurred in one patient with sarcoidosis. In the other five patients, the reason for abnormal FDG uptake (liver, lung, bone) remained unclear, and patients were treated as planned. Eleven months later, distant metastases were found in one patient at sites unrelated to the previous FDG uptake. CONCLUSION: The addition of FDG PET to the standard work-up of patients with LABC may lead to the detection of unexpected distant metastases. This may contribute to a more realistic stratification between patients with true stage III breast cancer and those who are in fact suffering from stage IV disease. Abnormal PET findings should be confirmed to prevent patients from being denied appropriate treatment.
Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Radiofármacos , Tomografía Computarizada de Emisión , Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/secundario , Adulto , Neoplasias de la Mama/patología , Carcinoma Ductal/diagnóstico por imagen , Carcinoma Ductal/secundario , Carcinoma Lobular/diagnóstico por imagen , Carcinoma Lobular/secundario , Reacciones Falso Negativas , Reacciones Falso Positivas , Femenino , Humanos , Persona de Mediana Edad , Metástasis de la Neoplasia/diagnóstico , Estadificación de Neoplasias , Estudios Prospectivos , Tomografía Computarizada por Rayos XRESUMEN
The aim of this study was to evaluate the in vivo performance of a prototype dual-crystal [lutetium oxyorthosilicate (LSO)/sodium iodide (NaI)] dual-head coincidence camera (DHC) for PET and SPET (LSO-PS), in comparison to BGO-PET with fluorine-18 fluorodeoxyglucose (FDG) in oncology. This follows earlier reports that LSO-PS has noise-equivalent counting (NEC) rates comparable to partial ring BGO-PET, i.e. clearly higher than standard NaI DHCs. Twenty-four randomly selected oncological patients referred for whole-body FDG-PET underwent BGO-PET followed by LSO-PS. Four nuclear medicine physicians were randomised to read a single scan modality, in terms of lesion intensity, location and likelihood of malignancy. BGO-PET was considered the gold standard. Forty-eight lesions were classified as positive with BGO-PET, of which LSO-PS identified 73% (95% CI 60-86%). There was good observer agreement for both modalities in terms of intensity, location and interpretation. Lesions were missed by LSO-PS in 13 patients in the chest ( n=6), neck ( n=3) and abdomen ( n=4). The diameter of these lesions was estimated to be 0.5-1 cm. Initial results justify further evaluation of LSO-PS in specific clinical situations, especially if a role as an instrument of triage for PET is foreseen.
Asunto(s)
Análisis de Falla de Equipo , Fluorodesoxiglucosa F18 , Cámaras gamma , Neoplasias/diagnóstico por imagen , Tomografía de Emisión de Positrones/instrumentación , Recuento Corporal Total/instrumentación , Adulto , Anciano , Anciano de 80 o más Años , Diseño de Equipo , Estudios de Factibilidad , Femenino , Humanos , Lutecio , Masculino , Persona de Mediana Edad , Proyectos Piloto , Tomografía de Emisión de Positrones/métodos , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Silicatos , Yoduro de Sodio , Transductores , Recuento Corporal Total/métodosRESUMEN
A prospective study was performed, comparing gallium scintigraphy (67Ga) and positron emission tomography (PET) using fluorine-18 fluorodeoxyglucose (18FDG), to monitor the response of aggressive non-Hodgkin's lymphoma during treatment. 67Ga and 18FDG scans were performed in 26 patients after two cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) therapy. The scans were reviewed independently by four experienced nuclear physicians, who were blinded for the alternative scan technique and follow-up. Eleven out of 26 patients remained free from progression with a mean follow up of 25 +/- 5 months, whereas 14 patients relapsed, and one died of lung cancer. Interobserver variation was significantly greater for 67Ga than for 18FDG PET. Some 64% of patients who had a negative early restaging 18FDG PET remained free from progression versus 50% of patients with negative 67Ga scans. Only 25% of patients with a positive PET remained disease free versus 42% of 67Ga-positive patients. Time to progression was associated with 18FDG PET results, but not with those by 67Ga. 18FDG PET had better test characteristics than 67Ga for the evaluation of early response in aggressive non-Hodgkin's lymphoma patients.
Asunto(s)
Fluorodesoxiglucosa F18/uso terapéutico , Linfoma no Hodgkin/diagnóstico , Linfoma no Hodgkin/tratamiento farmacológico , Radiofármacos , Tomografía Computarizada de Emisión , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Ciclofosfamida/administración & dosificación , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Doxorrubicina/administración & dosificación , Femenino , Radioisótopos de Galio , Humanos , Masculino , Persona de Mediana Edad , Prednisona/administración & dosificación , Pronóstico , Estudios Prospectivos , Inducción de Remisión , Tomografía Computarizada por Rayos X , Vincristina/administración & dosificaciónRESUMEN
Currently, up to 50% of the operations in early-stage non-small cell lung cancer (NSCLC) are futile owing to the presence of locally advanced tumour or distant metastases. More accurate pre-operative staging is required in order to reduce the number of futile operations. The cost-effectiveness of fluorine-18 fluorodeoxyglucose positron emission tomography ((18)FDG-PET) added to the conventional diagnostic work-up was studied in the PLUS study. Prior to invasive staging and/or thoracotomy, 188 patients with (suspected) NSCLC were randomly assigned to conventional work-up (CWU) and whole-body PET or to CWU alone. CWU was based on prevailing guidelines. Pre-operative staging was followed by 1 year of follow-up. Outcomes are expressed in the percentage of correctly staged patients and the associated costs. The cost price of PET varied between
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/economía , Análisis Costo-Beneficio/métodos , Fluorodesoxiglucosa F18/economía , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/economía , Tomografía Computarizada de Emisión/economía , Anciano , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Femenino , Costos de la Atención en Salud/estadística & datos numéricos , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Estadificación de Neoplasias/economía , Estadificación de Neoplasias/métodos , Países Bajos , Radiofármacos/economía , Reproducibilidad de los Resultados , Medición de Riesgo/economía , Medición de Riesgo/métodos , Sensibilidad y Especificidad , Tomografía Computarizada de Emisión/métodosRESUMEN
PURPOSE: To test the hypothesis that radiation-induced, transient G2/M arrest could potentially sensitize tumor cells to a subsequent, well-timed radiation dose. METHODS: PC-3 human prostate cancer cells were treated using either radiotherapy or (186)Re-labeled hydroxyethylidene diphosphonate ((186)Re-HEDP) treatment in different combinations. The resulting cell cycle shift and clonogenic cell death were analyzed by DNA flow cytometry and colony forming cell assay, respectively. RESULTS: Radiation doses of 4 Gy and 8 Gy induced a transient G2/M arrest, with a maximum after approximately 16 h. The presence of 2 mM pentoxifylline effectively abrogated this radiation-induced G2 M arrest, confirming a cell-cycle checkpoint-mediated effect. A second dose of 4 Gy, timed at the height of the G2/M arrest, significantly increased clonogenic cell-kill compared to delivery after a suboptimal interval (10 h, 20 h or 25 h after the first radiation fraction). Moreover, timed second doses of 2 Gy, 3 Gy or 4 Gy yielded improved normalized treatment effects compared to non-pretreated control. Radionuclide treatment of PC-3 cells, using (186)Re-HEDP (0.74 MBq/ml and 1.48 MBq/ml; total dose: 4.1 and 8.2 Gy, respectively) also induced a dose-dependent G2/M accumulation, which sensitized the cells to a subsequent external radiation dose of 2 Gy or 4 Gy. The observed pattern of cell-cycle shift towards a predominance of the G2/M phase is in line with the lack of functional p53 in this cell line. CONCLUSIONS: Radiation-induced cell-cycle shift was shown to effectively confer increased radiosensitivity to prostate tumor cells. Optimally timed combination of radiotherapy and radionuclide therapy could thus significantly increase treatment efficacy.