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Study Objectives: To study the ability of positron emission tomography (PET) using 18-fluorodeoxyglucose (FDG) to distinguish between benign and malignant disease in exudative pleural effusions and pleural thickening., Design: Prospective study of 98 consecutive patients presenting with either pleural thickening or an exudative pleural effusion., Setting: Department of pulmonary medicine of a university hospital., Methods: FDG-PET was performed on each subject before invasive procedures were used to determine the etiologic diagnosis. FDG-PET data were analyzed by visual interpretation., Results: Sixty-three of 98 patients were found to have malignant pleural disease after histologic analysis. Sixty-one of 63 patients with histologically confirmed malignant disease showed FDG uptake within the area of pleural thickening. Uptake was graded as intense in 51 cases and moderate in 10 cases. Only two patients with malignant pleural disease did not show increased FDG uptake. FDG-PET imaging showed an absence of FDG uptake, and correctly classified 31 of 35 benign lesions. For the remaining four lesions, intense FDG uptake was seen in one case of parapneumonic effusion, while moderate and localized uptake was observed in one parapneumonic, one tuberculous, and one uremic pleurisy. The sensitivity of the method to identify malignancy was 96.8% with a negative predictive value of 93.9%, while its specificity was 88.5% and its positive predictive value was 93.8%., Conclusions: Our results suggest that FDG-PET is an effective tool for differentiating between benign and malignant pleural diseases.

18 FDG- PET is an imagining technique based on metabolic criteria rather than morphological criteria. (18) FDG- PET can demonstrate accelerated glycosis in cancer tissue related to increased transporter and glycolytic enzyme activity. Whole body PET is currently under validation in a growing number of indications during diagnostic and therapeutic assessment phases of cancer treatment. In the field of pulmonary oncology, (18) FDG- PET has already demonstrated its performance capacity to: 1) discriminate the malignant nature of a solitary pulmonary nodule, 2) improve sensitivity over CT for mediastinal assessment in small-cell lung cancer, 3) acquire whole body imaging to search for distant metastasis in patients with small-cell lung cancer; PET is particularly useful for evaluation of an adrenal mass, 4) complement CT imaging to better dissociate tumor residue or recurrence from post-therapeutic sequelae in small-cell lung cancer. Information provided by (18) FDG- PET is thus clinically relevant as it allows better dissociation of a benign process from a malignant process and better precision of small-cell lung cancer extension without necessitating systematic invasive exploration.

Continuing advances in PET imaging have resulted in an improved ability to evaluate thoracic malignancies. Published reports demonstrate that PET provides accurate noninvasive detection of malignancy that is useful in the characterization of a pulmonary solitary nodule and in the mediastinal or extrathoracic staging of known lung cancer. Preliminary studies suggest that PET may also be able to assess the therapeutic response after surgery or radiation therapy.

In order to evaluate the usefulness of 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) in the assessment of therapeutic effects, a study was performed before and after therapy in 126 patients with non-small cell lung cancer (NSCLC) codified stage I to stage IIIB. Treatment with an early curative result was given in 58 patients, whereas in 68 cases it was limited to palliation. During the treatment follow-up period (8-40 months), each patient was evaluated every 3 months by clinical examination and < or =6 months by imaging techniques (PET and computed tomography (CT)). A diagnosis of persistent or recurrent tumour was established by means of pathological analysis in 31 patients and by clinical evolution and subsequent imaging progression in 29 other patients. PET showed increased FDG uptake in all cases (n = 60) of persistent or recurrent tumour, whereas CT was nonspecific in 17 cases. Conversely, there were five false positive cases via PET imaging and three via CT. In detecting residual or recurrent NSCLC, PET had a sensitivity of 100% and specificity of 92%, whereas CT had a sensitivity and specificity of 71% and 95% respectively. In conclusion, 18-fluorodeoxyglucose positron emission tomography correctly identified response to therapy in 96% (121 of 126) of patients. Positron emission tomography appears to be more accurate (p = 0.05) than conventional imaging in distinguishing persistent or recurrent tumour from fibrotic scar in patients undergoing treatment for non-small cell lung cancer.

Despite advances in morphological imaging, some patients with lung cancer are found to have non resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using bone scintigraphy, which has a high sensitivity but a poor specificity. We have attempted to evaluate the utility of the fluorine-18 deoxyglucose positron emission tomography (FDG PET) for the detection of bone metastasis. One hundred and ten consecutive patients with histological diagnosis of non-small cell lung cancer (NSCLC) who underwent both FDG PET and bone scintigraphy were selected for this review. In this group, there were 43 patients with metastatic disease (stage IV). Among these, 21 (19% of total group) had one or several bone metastases confirmed by biopsy (n = 8) or radiographic techniques (n = 13). Radionuclide bone scanning correctly identified 54 out of 89 cases without osseous involvement and 19 out of 21 osseous involvements. On the other hand, FDG PET correctly identified the absence of osseous involvement in 87 out of 89 patients and the presence of bone metastasis in 19 out of 21 patients. Thus using PET there were two false-negative and two false-positive cases. PET and bone scanning had, respectively, an accuracy of 96% and 66% in the evaluation of osseous involvement in patients with NSCLC. In conclusion, our data suggest that whole-body FDG PET may be useful in detecting bone metastases in patients with known NSCLC.

Background: Assessment of metastatic involvement of the liver remains a diagnostic challenge. The objective of this study was to evaluate the potential role of FDG PET in the detection of liver metastases., Patients and Methods: Sixty-four patients with malignancy and possible liver involvement were included. Liver metastases were present in 31 cases, demonstrated by histopathological analysis in 15 cases and by follow-up in 16 cases. The negative cases were confirmed by pathology in four cases, peroperative ultrasonography in 12 cases, and follow-up in 17 cases. Whole-body FDG PET was compared to CT (n = 53) and US (n = 43)., Results: PET demonstrated a 97% sensitivity, an 88% specificity and a 92% accuracy, compared to 93%, 75% and 85%, respectively, for CT (P = NS). Concordant results were obtained in 44 of 64 patients (69%: 19 TP. 25 TN). PET provided new and accurate information in 15 of 64 patients (23.4%). PET demonstrated liver metastases in 11 patients in whom conventional methods yielded negative (two cases) or doubtful (nine cases) results. Four patients free of liver involvement were correctly staged with PET, while CT/US were equivocal. PET was erroneous in five of 64 cases (7.8%, four FP, one FN)., Conclusions: FDG PET allows an accurate screening of liver involvement in patients with malignancy. Combined with CT, it provides additional diagnostic information that could directly affect the management of these patients.

Despite advances in morphological imaging, some patients with lung cancer are found to have nonresectable disease at surgery or die of recurrence within yr of surgery. We performed a prospective study in 109 patients to compare the accuracy of whole-body positron emission tomography (PET) using fluorine-18 deoxyglucose (18FDG) and conventional imaging (CI) methods for the staging of non-small cell lung cancer (NSCLC). When CI or PET study suggested metastatic disease, confirmation was obtained by biopsy or follow-up information. As compared to CI, 18FDG-PET correctly changed the N stage in 22 patients (33%) and the M stage in 15 patients (14%). For the detection of distant metastases, PET study showed five false-positive sites and no false-negative cases. Currently, the accuracy of PET in the detection of M stage is 96%. Our study shows that visual interpretation of whole-body fluorine-18 deoxyglucose-positron emission tomography images can improve the diagnostic accuracy in the staging of non-small cell lung cancer. Further experience is needed to establish if metabolic imaging would be a cost-effective tool in the future management of lung cancer.

Background: Positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) is an accurate method for differentiating benign from malignant disease. The use of FDG-PET for the aetiological diagnosis of pleural disease was investigated in 25 patients., Methods: PET was performed on each subject before invasive procedures were used to determine the aetiological diagnosis. The PET data were analysed by visual interpretation of coronal, sagittal, and transverse slices., Results: Sixteen patients were found to have malignant pleural disease and nine had benign disease. All patients with histologically confirmed malignant disease showed FDG uptake within the pleural thickening which was intense in 14 cases and moderate in two. PET imaging showed the absence of FDG uptake and correctly categorised seven non-malignant lesions. Two patients with infectious pleural diseases showed a localised and moderate FDG uptake., Conclusion: Our preliminary results suggest that FDG-PET could be an effective tool for differentiating between benign and malignant pleural diseases.

Positron emission tomography (PET) is now primarily used in oncological indication owing to the successful application of fluorine-18 fluorodeoxyglucose (FDG) in an increasing number of clinical indications at different stages of diagnosis, and for staging and follow-up. This review first considers the biological characteristics of FDG and then discusses methodological considerations regarding its use. Clinical indications are considered, and the results achieved in respect of various organs and tumour types are reviewed in depth. The review concludes with a brief consideration of the ways in which clinical PET might be improved.

Recent studies have shown limitations of morphological imaging in staging mediastinal lymph node involvement in lung cancer. In contrast to computed tomography (CT), which depends primarily on anatomical imaging features, positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) depends mainly on the metabolic characteristics of a tissue for the diagnosis of disease. We have performed a prospective study comparing FDG-PET and CT of the thorax in the presurgical assessment of the mediastinum in 50 patients with newly diagnosed non-small cell lung cancer (NSCLC). CT and PET scans were interpreted separately, and results were compared to pathological staging obtained during thoracotomy. Hilar or mediastinal lymph node involvement was present in 58%. In staging for lymph node involvement, CT had a sensitivity of 72% and specificity of 81%, whereas PET had a sensitivity and specificity of 90% and 86%, respectively. When the PET study was compared to histological results, there were four cases showing more advanced mediastinal involvement with PET and four cases showing less involvement with PET. From our preliminary results, we conclude that positron emission tomography with 18-fluorodeoxyglucose is significantly more accurate than computed tomography in the mediastinal staging of non-small cell lung cancer.

Current methods for evaluating the mediastinum include chest radiography, computed tomography (CT) or magnetic resonance (MR) imaging and mediastinoscopy. Despite advances in morphologic imaging, some lung cancer patients are found to have unresectable disease at surgery. In contrast to CT scan or MR imaging, which depend primarily on anatomic and morphological criteria, positron emission tomography (PET) with 18fluorodeoxyglucose (FDG) depends mainly of the metabolic characteristics of a tissue for the diagnosis of disease. We perform a prospective study to compare FDG-PET and CT of the thorax in the presurgical assessment of the mediastinum in patients with newly diagnosed non-small cell lung cancer. Thirty patients have been included. CT and PET-scans were interpreted separately and results were compared to surgical staging during thoracotomy. In assessing mediastinal involvement, CT scan had a sensitivity of 56% and a specificity of 64%. For diagnosis mediastinal nodal disease, FDG-PET was 87% sensitive and 78% specific. Its positive predictive value was 82%, and the negative value was 83%. In conclusion, our preliminary results show that FDG-PET appears more accurate than CT in staging of mediastinal non-small cell lung cancer.

Current noninvasive imaging methods are not sufficiently reliable for accurate detection of malignancy in most solitary pulmonary nodules (SPNs). Positron emission tomography (PET) using 18-fluorodeoxyglucose (FDG), showing increased FDG uptake and retention in malignant cells, has proved useful to differentiate malignant from benign tissue and could, therefore, contribute to the evaluation of the SPN. We performed a prospective study of 50 patients referred to the Pneumology Department with unclear diagnoses of SPN after conventional radiological screening. PET study was performed on each subject before an invasive procedure was proposed. Thirty three patients had a malignant nodule and 17 had a benign nodule. The mean size of malignant nodule was 3 cm (range 1.5-4.5 cm). All showed a marked increase in 18-FDG uptake. The mean size of benign nodule was 1.8 cm (range 0.5-3.5 cm). PET imaging showed the absence of 18-FDG uptake and correctly identified 15 of 17 benign nodules. There was two false-positive cases with a moderate increase in 18-FDG uptake (1 postprimary tuberculosis; and 1 anthracosilicotic nodule with nonspecific inflammation). At present, the sensitivity and specificity of the method are 100 and 88%, respectively. The positive and negative predictive values of PET imaging for SPNs are 94 and 100%, respectively. Our preliminary results demonstrate that PET-FDG imaging is a noninvasive technique, which appears highly accurate in differentiating malignant SPN from benign SPN.

Positron emission tomography (PET) using fluorine-18 deoxyglucose (FDG), showing increased FDG uptake and retention in malignant cells, has been proven useful to differentiate malignant from benign tissue. We undertook a prospective study in 61 patients to compare the accuracy of whole-body FDG PET and conventional imaging (CI) methods for the staging of non-small-cell lung cancer (NSCLC). CI included chest and abdomen computed tomographic scanning and bone scintigraphy. When CI or PET study suggested metastatic disease, confirmation was obtained by biopsy or clinical or radiological follow-up. As compared to CI, PET correctly changed the N stage in 13 patients (21%) and the M stage in six patients (10%). There were three false-positive and no false-negative distant PET findings. Our preliminary results show that whole-body FDG PET can improve the diagnostic accuracy in the staging of NSCLC.