Abstract: BACKGROUND AND OBJECTIVE: To study the behaviour of 18F-FDG-PET in patients with in situ breast carcinomas. PATIENTS AND METHOD: The study group included 19 women with a tumor size between 0.8 and 2.2 cm. An uptake in breast with a SUV > 1.9 was considered as positive. RESULTS: 18F-FDG-PET was positive in 8 patients (SUV; range 0.6-2.8; 1.64 [0.59]) and only when the tumor size was higher than 1 cm. Likewise, only in the PET-positive tumors, an inverse (r = -0.637) and positive (p < 0.05) correlation between SUV and weight of patients was observed. When we compared the results with those obtained in 28 patients having infiltrating ductal carcinomas of the breast, we observed that the 18F-FDG-PET was positive only in tumors > 1 cm also, but the percentages of positives (89%) were higher than those obtained in in-situ carcinoma, regardless of tumor size. CONCLUSIONS: The percentage of positive results of 18F-FDG-PET in in-situ breast carcinomas and the SUV are lower than those observed in infiltrating ductal carcinomas, regardless of tumor size. Those carcinomas can be a source of false negative results with such imaging technique.
Abstract: The introduction of positron emission tomography (PET) into the management of neoplastic disease in respiratory patients signified an important change from classic algorithms based exclusively on anatomic information obtained through computed tomography (CT). Non-small cell lung cancer and solitary pulmonary nodule were the 2 diseases in which metabolic PET imaging offered the highest diagnostic yield, as has been evident since the inclusion of this technology among the services available within the Spanish national health service. However, a number of limitations were encountered in relation to the lack of anatomic definition in PET imaging, as had been described in the literature. The appearance in 2001 of hybrid PET-CT devices has not only helped remedy those defects, but has also made it possible to combine anatomic and metabolic information in a single image, making this hybrid technology the most valuable tool in the current diagnostic arsenal.
Abstract: Anatomic imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) have been used for many years in clinical oncology. The emergence of positron emission tomography (PET) more than a decade ago was a major breakthrough in the early diagnosis of malignant lesions, as it was based on tumour metabolism and not on anatomy. The merger of both techniques into one thanks to PET-CT cameras has made this technology the most important tool in the management of cancer patients. PET/CT with 18F-FDG is increasingly being used for staging, restaging and treatment monitoring for cancer patients with different types of tumours (lung, breast, colorectal, lymphoma, melanoma, head and neck etc.). At many institutions, PET/CT has replaced separately acquired PET and CT examinations for many oncologic indications. This replacement has occurred despite the fact that only a relatively small number of well designed prospective studies have verified imaging findings against the gold standard of histopathologic tissue evaluation. However, a large number of studies have used acceptable reference standards, such as pathology, imaging and other clinical follow-up findings, for validating PET/CT findings. The impact on the management of patients and the benefits from the information obtained from this anatomo-metabolic procedure justify the term "clinical oncology based on PET-CT" as a new concept to be applied in clinical practice.
Abstract: In the present work, several experimental approaches were used to determine the presence of the glucagon-like peptide-1 receptor (GLP-1R) and the biological actions of its ligand in the human brain. In situ hybridization histochemistry revealed specific labelling for GLP-1 receptor mRNA in several brain areas. In addition, GLP-1R, glucose transporter isoform (GLUT-2) and glucokinase (GK) mRNAs were identified in the same cells, especially in areas of the hypothalamus involved in feeding behaviour. GLP-1R gene expression in the human brain gave rise to a protein of 56 kDa as determined by affinity cross-linking assays. Specific binding of 125I-GLP-1(7-36) amide to the GLP-1R was detected in several brain areas and was inhibited by unlabelled GLP-1(7-36) amide, exendin-4 and exendin (9-39). A further aim of this work was to evaluate cerebral-glucose metabolism in control subjects by positron emission tomography (PET), using 2-[F-18] deoxy-D-glucose (FDG). Statistical analysis of the PET studies revealed that the administration of GLP-1(7-36) amide significantly reduced (p < 0.001) cerebral glucose metabolism in hypothalamus and brainstem. Because FDG-6-phosphate is not a substrate for subsequent metabolic reactions, the lower activity observed in these areas after peptide administration may be due to reduction of the glucose transport and/or glucose phosphorylation, which should modulate the glucose sensing process in the GLUT-2- and GK-containing cells.
Abstract: PURPOSE: Computed tomography (CT) and [18F] Fluorodeoxyglucose positron emission tomography (FDG-PET) are considered suitable methods for the noninvasive staging of the mediastinum. Our study was intended to estimate the efficacy of contrast-enhanced helical CT (hCT) and FDG-PET, alone and combined, in the diagnosis of lymph node mediastinal metastases. METHODS: This study was a prospective and blind comparison of the efficacy of hCT and FDG-PET with two alternative reference standards, mediastinoscopy, and mediastinoscopy plus thoracotomy plus a 6-month follow-up to diagnose lymph node mediastinal metastases in 132 consecutive patients with potentially resectable non-small-cell lung cancer (NSCLC). The metastatic disease was assessed histopathologically. Further clinical information was obtained postoperatively after a median follow-up of 42 months. RESULTS: The prevalence of cN2,3 is 0.28. For hCT the sensitivity and specificity are 0.86 (95% CI, 0.70 to 0.93) and 0.67 (95% CI, 0.56 to 0.75), for PET 0.94 (95% CI, 0.81 to 0.98) and 0.59 (95% CI, 0.49 to 0.68), and for hCT and PET combined in-parallel 0.97 (95% CI, 0.84 to 0.99) and 0.44 (95% CI, 0.34 to 0.53), which translate into a negative predicted probability of 0.98 (95% CI, 0.88 to 1.00). The crude diagnostic odds ratio of PET in the total sample studied is 13.1, in the subgroup hCT+ 11.04 (3.0 to 40 0.1), and in the hCT- 3.5 (0.5 to 21.5). Similar results were obtained for hCT stratified by PET. CONCLUSION: hCT and PET perform similarly in the mediastinal staging of NSCLC, both tests are conditionally dependent and provide complementary information, and their diagnostic value mainly resides on the negative results.
Abstract: INTRODUCTION: 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a diagnostic imaging tool with multiple applications in oncology. One of the more promising applications in breast cancer is noninvasive lymph node staging and detection of distant metastases, which may provide useful information about prognosis and treatment response. MATERIAL AND METHOD: Published studies on FDG-PET applications in breast cancer detection and staging were reviewed. We also present our own experience in patients referred for preoperative staging of breast cancer. RESULTS: FDG-PET is very useful in evaluating dense breasts, multicentric disease and breast prostheses. The sensitivity of FDG-PET for nodal staging is low, and consequently it cannot replace either sentinel lymph node biopsy or histologic examination. However, it is more accurate than another noninvasive techniques and is very useful in internal mammary node chain evaluation. FDG-PET can improve and maybe replace conventional imaging in detecting metastatic disease, especially in high risk patients with locoregionally advanced recurrent breast cancer or increased serum tumor markers, and helps to characterize unclear findings of anatomic imaging techniques or scintigraphy. CONCLUSIONS: FDG-PET is useful in breast cancer staging. It complements and even improves information from other diagnostic techniques and changes therapeutic management in a high proportion of patients.
Abstract: Positron Emission Tomography (PET) with 18F-Fluordeoxyglucose is a diagnostic imaging technique very useful in the management of head and neck cancer, better than anatomic imaging in most cases. PET shows higher diagnostic accuracy in the detection of local and regional tumor recurrences. PET is also indicated for the identification of unknown primary tumors when regional nodal metastasis is the presenting feature. The improved planning of radiation therapy with hybrid cameras PET-CT, the earlier diagnosis of post-radiotherapy residual disease and the possibility of monitoring the effects of chemotherapy makes PET imaging an important tool in evaluating tumor response to treatment.
Abstract: INTRODUCTION: Developmental disorders are a common pathological condition in Neuropaediatrics and do not usually present characteristic anatomical alterations in the different neuroanatomical imaging tests that can be employed, such as computerised axial tomography or magnetic resonance (MR). Positron emission tomography (PET) using [18F] fluorodeoxiglucose (PET FDG), one of the battery of imaging tests currently available, enables us to obtain data about brain activity in a non invasive manner. PATIENTS AND METHODS: A group of 39 patients with developmental disorders from the Hospital del Mar was analysed. They were submitted to PET FDG brain metabolism tests and in some cases hybrid PET MR images were also obtained; findings were then correlated against the clinical progression of the patients. RESULTS AND CONCLUSIONS: The alterations that were observed showed predominantly bilateral thalamic, mesial temporal and orbital frontal hypometabolism. This alteration of the limbic system, which has no correlation with anatomical damage, can be a predictor of the clinical progression and of the confirmation of the presence of alterations in the brain functions in this type of patients.
Abstract: Purpose: To retrospectively evaluate the contribution of 18F-fluorodeoxy-glucose-positron emission tomography (FDG-PET) to the diagnosis and clinical management of patients who were suspected of recurrent ovarian carcinoma, based on elevated tumor markers levels with normal or equivocal computed tomography (CT) or nuclear magnetic resonance (NMR).Procedures: 20 patients with these characteristics underwent FDG-PET. PET findings were confirmed in 14, in 7 by surgery, and in the other 7 by clinical course.Results: Recurrence was confirmed in 12 patients, all with FDG-PET positive. In other 2, recurrence was rule out and in 1, FDG-PET was negative. FDG-PET accuracy was 93% with 4 surgeries avoided and guided other 6.Conclusions: FDG-PET is an useful technique for detecting recurrent ovarian carcinoma suspected by elevated tumor markers levels and normal or equivocal results in the morphologic imaging techniques and has an important clinical impact on the management of these patients.
Abstract: PURPOSE: Evaluate the usefulness of Positron Emission Tomography with 18F-Fluorodeoxyglucose (FDG-PET) to detect lesions when tumor recurrences are suspected due to the progressive increase of tumor markers and the study of their extension with negative or non-conclusive morphostructural diagnostic techniques. MATERIAL AND METHODS: Whole body FDG-PET was per-formed in 72 patients with different cancer diseases, 23 of whom had breast, 18 colorectal, 15 thyroid, 6 lung, 3 ovarian cancer and 7 had other types of cancers. Tumoral recurrence was suspected in all of the cases due to the progressive marker increase and negative or non-conclusive conventional studies. RESULTS: FDG-PET detected lesions in 85% patients, 33% of which were confirmed by the end of the study. In 40% of all cases, therapeutics measures were applied, 14% of which consisted in surgery with intention to cure. Sensitivity, specificity and accuracy were 96.4%, 75.6% and 93.9% respectively. CONCLUSIONS: Whole body FDG-PET is an accurate procedure in diagnosis of recurrent tumoral disease in patients with rising tumoral marker levels and with negative conventional morphostructural extension studies, and can make it possible to change the therapeutic approach in some cases.
Abstract: Purpose: FDG-PET images and EEG dipole modelling were used to localization of interictal epileptogenic foci. A multimodality approach with the analysis of FDG-PET images, EEG dipoles and anatomical images (MRI) were applied to patients with drug-resistant epilepsy.Methods: Source location was determined using Brain Electromagnetic Source Analysis (BESA) program. The dipole location provided by BESA was then transformed into PET co-ordinates using the patient's MRI previously registered with the PET image. As a difference with other methods, no external markers are necessary.Results: The study group includes ten drug-resistant epileptic patients. FDG hypometabolism was found in all patients. Abnormalities in glucose uptake were always ipsilateral to the EEG dipole. However, quantitative analysis of FDG-PET within hypometabolic areas showed no significant correlation between decrease glucose uptake and location of EEG-dipole source. The comparison of the results using both methods shows that the dipole location matches the FDG-PET hypometabolic area for all the patients. Combining the spatial localization on FDG-PET with the temporal accuracy of EEG dipole source aids in the exact localization of the epileptogenic focus.Conclusion: As a conclusion, the results show that projection of EEG dipole data onto FDG-PET may play a key role in the indication of surgery for the treatment of drug-resistant epileptic patients, provided it is simple and easy to perform.
Abstract: Purpose: A rising CEA level after the resection of colorectal cancer is an early indicator of tumour recurrence. However, conventional imaging techniques have limited sensitivity for detecting recurrent disease in such patients. Our group has evaluated the role of Positron Emission Tomography with 18F-Fluorodeoxiglucose (FDG-PET) in this clinical situation.Material and Methods: Seventy-two patients with abnormal CEA levels and normal results of conventional methods of tumour detection were studied with FDG-PET. The PET results were compared with pathologic findings (n = 25) long-term radiological (n = 9) and clinical follow-up (n = 38). Influence of PET findings in therapeutic management was also considered in this study.Results: PET detected lesions in 63/72 patients (87.1%). Metabolic imaging showed metastases in the liver (44.1%), ganglionar nodes (27.5%), local recurrence (20.4%) and lung metastases (8%). Overall, the sensitivity of PET was 94.4%, specificity was 83.3%, the positive-predictive value was 97.1%, the negative-predictive value was 71.4% and the diagnostic accuracy was 92.8%. FDG-PET findings change therapeutic decision in 68/72 patients (94.1%)Conclusion: When conventional examinations are normal, FDG-PET is a valuable imaging tool in patients who have rising CEA level after colorectal surgery. Metabolic imaging represents a very cost-effectiveness diagnostic procedure in this clinical situation, avoiding unnecessary invasive techniques.
Abstract: Purpose: SCC represents nearly 90% of all oral malignancies, with an increasing incidence. Accurate Tumour-Node-Metastasis staging (TNM) is mandatory for planning surgical options and chemotherapy-radiotherapy management. Positron Emission Tomography (PET) using 18F-Fluorodeoxyglucose (FDG) provides functional information about tumoral tissues that may improve preoperative staging obtained by conventional morphologic procedures (CT-MRI). The purpose of this study is to evaluate the accuracy of FDG-PET in oral SCC staging and to compare those data from conventional and PET studies according to the pathologic results obtained from surgical specimen.Methods: A prospective study of 30 patients was carried out, through a 26 months period. Inclusion criteria include positive biopsy for Oral SCC, no other malignancies during the past 5 year and surgery as preferred therapeutic option. All patients underwent CT, MRI, and FDG-PET studies consecutively. Results obtained from conventional and PET preoperative staging were compared with those from postoperative histopathological studiesResults: FDG-PET modified preoperative staging obtained by conventional morphologic studies in 21% cases, which was confirmed postoperatively by histological findings. Kappa test showed higher values for PET studies (0.89) than conventional studies (0.41), when compared with postoperative controlConclusion: FDG-PET may be helpful to improve the accuracy of conventional studies in oral SCC preoperative TNM staging, although no definitive conclusions can be withdrawn due to the limited size of the sample. Modifications of preoperative staging showed by PET are a matter of controversy and must be kept in mind for further studies.
Abstract: The value of whole body PET-FDG in the evaluation of metastases has been demonstrated in a wide variety of tumors. In this report, we present the case of a patient with antecedent of papillary thyroid carcinoma, who was operated twelve years ago, and submitted to an ablative dose of residual thyroid tissue through 131I, being the levels of thyroglobulin normals. After twelve years of evolution, the patient refers bag pain and respiratory trouble, appearing in the CT image suspicious of metastases in right pulmonary base. The levels of thyroglobulin were shown increased, being the 131I scan negative. A whole body PET-FDG study was performed in order to exclude metastases of his malignant process, showed multiple high FDG uptake focus in brain, cerebellum, neck, chest, lymphatic nodes and bone, suggestive of dedifferentiated disease These findings were confirmed subsequently in the clinic evolution. Therefore, whole-body PET-FDG is a complementary diagnostic technique for study patients with CDT (Thyroid Differentiated Carcinoma) with 131I scan negative and rising thyroglobulin levels.
Abstract: INTRODUCTION: We believe that it is of great interest, in neuropediatric clinic, to value the molar behavior disorders and to accomplish the corresponding molecular alterations in the central nervous system. PATIENTS AND METHODS: We studied 26 patients diagnosed of serious disorders of the development, that were presenting a typical clinic with manual stereotypes. We choose at random 5 children to practice them a study of metabolic neuroimaging through the Positron Emission Tomography with 18Fluoro-Deoxi-Glucose (PET-FDG). RESULTS AND CONCLUSIONS: The conclusion, more meaningful, is that the children with serious disorders of the development present a mature failure in the neuro-function circuits of the thalamus, as well as the cortical connection and association areas. This clinical situation is reinforced by the results of the PET-FDG, that presents a characteristic metabolic image of the autism children, with a bilateral decrease of the capitation of FDG, mainly in regions as thalamus, frontal and temporary lobes.
Abstract: INTRODUCTION: Although CT and MR are sensitive techniques for the detection of cerebral tumours, both have limitations in distinguishing between tumour relapse (TR) and post-treatment radionecrosis (RN). PATIENTS AND METHODS: In this study we have determined the usefulness of metabolic imaging with PET-FDG in such situations. We assessed 70 patients with CNS tumours (22 low grade astrocytomas, 25 high grade astrocytomas, 3 oligodendrogliomas, 13 metastatic tumours and 7 other tumours. All had been treated with radiotherapy and other treatments such as radiosurgery, chemotherapy or different types of surgery, and presented clinical pictures which made it necessary to decide the differential diagnosis of relapse or radionecrosis. RESULTS: In the PET-FDG study visual and semiquantitative analysis was done by SUV (Standardized Update Value). Confirmation of the findings was obtained in 44 cases (24 TR and 20 RN). MR was doubtful or inconclusive in most cases, whilst with PET correct diagnosis was made in all cases. CONCLUSIONS: Metabolic imaging with PET-FGD is better than anatomostructural imaging techniques for differential diagnosis between tumour relapse and radionecrosis in CNS tumours which have been treated. Prospective studies are necessary for evaluation of SUV as a factor for prognosis of survival.
