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Objective: The aim of this study was to determine the stage and outcome of patients with primary lung tumors who had a negative finding on a FDG positron emission tomography (PET) study at the time of diagnosis., Materials and Methods: A total of 3912 patients between November 1994 and August 2002 underwent thoracic or whole-body PET performed at our institution for evaluation of a pulmonary abnormality suspicious for lung cancer. We identified 20 patients with a biopsy-proven primary lung tumor and a negative PET study at the time of presentation. Surgical, pathologic, radiographic imaging, and clinical follow-up information were reviewed to confirm the histology, stage, and outcome., Results: Tumor histology included adenocarcinoma (n = 7, 35%), bronchioalveolar cell carcinoma (n = 6, 30%), carcinoid (n = 3, 15%), squamous cell carcinoma (n = 2, 10%), otherwise unspecified non-small cell lung cancer (n = 1, 5%), and sarcomatoid neoplasm (n = 1, 5%). One patient with bronchioalveolar cell carcinoma had multifocal stage IV disease, and all other patients were stage IA (n = 14, 70%) or stage IB (n = 5, 25%). Eighteen (90%) of the 20 patients underwent curative surgical resection. No patient is known to have tumor recurrence after resection, and three (17%) of the 18 patients are known to be living and free of disease 5 years after surgery., Conclusion: With the exception of bronchioalveolar cell carcinoma and carcinoid, newly diagnosed lung cancers with negative PET findings are usually early-stage diseases and are associated with a favorable prognosis, suggesting that indeterminate pulmonary nodules, which are PET-negative, can be managed conservatively with serial radiographic studies to monitor for signs of growth. These findings warrant further study and should be confirmed with sufficient follow-up in a large cohort of patients with PET-negative lung lesions.

Purpose: To determine the sensitivity of fluorodeoxyglucose (FDG) positron emission tomography (PET) in patients with T1 (< or =3 cm) lung cancers., Materials and Methods: One hundred eighty-five patients with 192 histopathologically proved T1 lung cancers underwent FDG PET imaging at the time of diagnosis. PET results were correlated with tumor size, histopathologic findings, and patient outcome by using the two-sample t test, exact chi(2) test, and log rank test, respectively., Results: Of the 192 lesions, 183 (95%) that ranged in size from 0.5 to 3.0 cm in diameter (mean, 2.0 cm) were positive at PET (ie, demonstrated increased FDG uptake). Of the 192 lesions, nine (5%) that ranged in size from 0.3 to 2.5 cm in diameter (mean, 1.3 cm) were negative at PET (ie, demonstrated low FDG uptake). Patients with small tumors, as well as those with carcinoid tumors and bronchioloalveolar cell carcinoma, were more likely to have a negative PET scan (P =.004, P =.003, respectively). In addition, patients with a negative PET scan who subsequently proved to have cancer had significantly longer survival than did patients with a positive scan and cancer (P =.043)., Conclusion: Most T1 lung cancers show increased FDG uptake on PET scans., (Copyright RSNA, 2002)

Paraneoplastic syndromes may be the presenting clinical manifestation of small cell lung cancer. In some cases, however, confirming the diagnosis can be difficult because findings on conventional imaging studies can be subtle or nonspecific. This study examined the utility of fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) in identifying clinically suspected small cell lung cancer in patients with paraneoplastic syndromes. FDG-PET appears to be very useful in localizing suspected small cell lung cancer in patients presenting with paraneoplastic syndromes.

Purpose: To determine the accuracy of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the evaluation of regional lymph nodes in patients with stage I non-small cell lung cancer (NSCLC)., Materials and Methods: Imaging and clinical findings obtained during 5 years in 84 patients (mean age, 66 years) were reviewed. Patients had thoracic computed tomographic findings of stage I NSCLC, an FDG PET study, and histopathologic proof of lung cancer. At the time of diagnosis, disease stage was assigned on the basis of FDG PET results and was compared with the histopathologic stage to determine the accuracy of PET., Results: When PET stage was compared with histopathologic stage, the disease in 72 (86%) patients was accurately staged with PET, understaged in two (2%), and overstaged in 10 (12%). The overall sensitivity, specificity, and positive and negative predictive values for PET of regional lymph nodal metastases were 82%, 86%, 47%, and 97%, respectively., Conclusion: FDG PET enables accurate staging of regional lymph node disease in patients with stage I NSCLC. A negative PET scan in these patients suggests that mediastinoscopy is unnecessary and that these patients can proceed directly to thoracotomy.

Objective: We determined the prognostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for patients with treated lung cancer., Materials and Methods: We examined patients who underwent FDG PET after first-line treatment for non-small cell lung cancer. FDG PET results were correlated with survival rates to determine whether FDG PET findings were predictive of outcomes., Results: After initial therapy, 113 patients with non-small cell lung cancer underwent FDG PET. One hundred patients had positive FDG PET results and a median survival of 12 months (95% confidence interval, 9.2-15.4). Thirteen patients had negative FDG PET results, and 11 (85%) of these patients are still living at a median follow-up of 34 months. The difference in survival for patients with positive and negative FDG PET results was statistically significant (p = 0.002)., Conclusion: FDG PET has prognostic value and strongly correlates with survival rates of patients with treated lung cancer. Patients with positive FDG PET results have a significantly worse prognosis than patients with negative results. Additionally, FDG PET may be helpful in guiding therapeutic treatments.

Positron emission tomography imaging has proven valuable in the evaluation and management of thoracic abnormalities. It is more accurate than CT or MR imaging in characterizing indeterminate focal abnormal pulmonary opacities, staging lung cancer, and assessing the therapeutic response. PET imaging in lung cancer also appears to be cost-effective, particularly with whole-body studies. The metabolic and physiologic abnormalities used in FDG-PET imaging, rather than conventional anatomic or morphologic characteristics, provide an invaluable model for the future of tumor imaging.

Positron emission tomography is a clinically useful imaging modality that complements conventional radiologic studies in the evaluation of focal pulmonary opacities, lung cancer staging, tumor recurrence, treatment response, and prognosis.

Purpose: To compare the accuracies of whole-body 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) and conventional imaging (thoracic computed tomography [CT], bone scintigraphy, and brain CT or magnetic resonance [MR] imaging) in staging bronchogenic carcinoma., Materials and Methods: Within 20 months, 100 patients with newly diagnosed bronchogenic carcinoma underwent whole-body FDG PET and chest CT. Ninety of these patients underwent radionuclide bone scintigraphy, and 70 patients underwent brain CT or MR imaging. For each patient, all examinations were completed within 1 month. A radiologic stage was assigned by using PET and conventional imaging independently and was compared with the pathologic stage. The accuracy, sensitivity, specificity, and negative and positive predictive values were calculated., Results: PET staging was accurate in 83 (83%) patients; conventional imaging staging was accurate in 65 (65%) patients (P < .005). Staging with mediastinal lymph nodes was correct by using PET in 67 (85%) patients and by using CT in 46 (58%) patients (P < .001). Nine (9%) patients had metastases demonstrated by using PET that were not found with conventional imaging, whereas 10 (10%) patients suspected of having metastases because of conventional imaging findings were correctly shown with PET to not have metastases., Conclusion: Whole-body PET was more accurate than thoracic CT, bone scintigraphy, and brain CT or MR imaging in staging bronchogenic carcinoma.

Background: A fundamental property of malignant tumors is increased glucose metabolism, which can be estimated by imaging the glucose analog fluorodeoxyglucose (FDG). The aim of this study was to determine whether FDG uptake in lung carcinoma, as measured on positron emission tomography (PET) imaging in patients with newly diagnosed bronchogenic carcinoma, has prognostic significance., Methods: A retrospective review of all patients with a new diagnosis of nonsmall cell lung carcinoma and FDG-PET imaging was performed. Stage at presentation, cell type, tumor size, and survival data were recorded. For each patient, a standardized uptake ratio (SUR) was calculated for the primary lesion on PET and was correlated with clinical information to determine prognostic significance., Results: One hundred fifty-five patients, with a mean age of 56 years, were enrolled. One hundred eighteen patients (76%) had lesions with SUR values <10 and had a median survival of 24.6 months (95% confidence interval [CI]: 20.9-41.1). Thirty-seven patients (24%) had tumor lesions with SUR values >10 and had a median survival of 11.4 months (95% CI: 9.3-19.4). An SUR >10 correlated with poorer survival (P = 0.0049). Patients with primary lesions >3 cm and an SUR > 10 had the worst prognosis, with a median survival of 5.7 months (95% CI: 4.0-13.1). Multivariate analysis demonstrated than an SUR > 10 provided prognostic information independent of the clinical stage and lesion size., Conclusions: On PET studies of patients with lung carcinoma, FDG uptake within the primary lesion correlates with survival.

The evaluation of mediastinal lymph nodes is an important aspect of staging in patients with non-small cell lung cancer. Anatomic imaging of lymph nodes with computed tomography (CT) and magnetic resonance (MR) imaging has been limited by the relatively low sensitivity and specificity of these techniques. Advances in physiologic imaging of mediastinal lymph nodes with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) have resulted in improved diagnostic accuracy in the determination of nodal status. Despite the limitations of CT, this technique still plays an important role by aiding in the selection of the most appropriate procedure for staging, by guiding biopsy, and by providing anatomic information for visual correlation with FDG PET images. At present, anatomic MR imaging of lymph nodes is primarily a problem-solving tool for cases with inconclusive CT results. Physiologic MR imaging with iron oxide is an exciting area of investigation, and the accuracy of this technique is being assessed in clinical trials. Anatomic and physiologic imaging techniques should be considered complementary rather than competitive imaging strategies.

Objective: The purpose of this study was to determine the spectrum of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) findings in patients who have primary pulmonary carcinoid tumors., Conclusion: On FDG PET imaging, pulmonary carcinoid tumors usually have lower FDG uptake than expected for malignant tumors. Biopsy or close radiologic follow-up is therefore recommended for solitary pulmonary nodules that are clinically suspected of being carcinoid tumors and that do not show increased metabolic activity on FDG PET images.

The D-glucose analogue 2-(fluorine-18) fluoro-2-deoxy-D-glucose (FDG) is the most commonly used radionuclide in positron emission tomography (PET) of the thorax. Increased glucose metabolism by malignant cells allows physiologic differentiation between benign and malignant abnormalities. FDG PET is consequently useful in characterizing indeterminate pulmonary nodules and in staging and assessing the response to treatment of lung cancer. FDG PET is accurate in classification of indeterminate pulmonary nodules as benign. Nodules with low FDG uptake are followed up radiographically; nodules with increased FDG uptake should be evaluated with biopsy or resected. In the staging of lung cancer, FDG PET is useful in evaluating local disease and pleural and chest wall involvement. The accuracy of FDG PET in demonstrating intrathoracic metastatic nodal disease is greater than that of computed tomography or magnetic resonance imaging. Whole-body PET is useful in detection of extrathoracic metastases. Conventional imaging often does not allow differentiation of tumor from posttreatment scarring. Increased FDG uptake at the sites of residual radiographic abnormalities is indicative of persistent or recurrent tumor.

Objective: The purpose of this study was to assess the usefulness of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) when differentiating benign from metastatic adrenal masses in patients with bronchogenic carcinoma., Subjects and Methods: For our prospective study, any patient presenting to our institution with pathologically proven bronchogenic carcinoma and an adrenal mass was eligible. Thirty-three adrenal masses (mean size, 3 cm; range, 1-9 cm) in 27 patients were revealed by CT. PET was performed in all 27 patients and interpreted as positive when FDG uptake in the adrenal mass was greater than background activity or negative when FDG uptake in the adrenal mass was equal to or less than background activity. In addition, semiquantitative analysis was performed by computing a standardized uptake ratio. All studies were reviewed independently by three radiologists and then correlated with biopsy and CT findings. Specificity and sensitivity for determining metastatic disease to the adrenal gland were calculated., Results: FDG uptake was positive (abnormally increased) in 25 adrenal masses. Twenty-three (92%) of the 25 masses were metastatic disease. The mean standardized uptake ratio of these was 6.28 (range, 3.22-14.41). The remaining two masses (8%) that had positive FDG uptake showed no tumor at percutaneous biopsy. The standardized uptake ratio values for these two masses were 3.0 and 3.7. FDG uptake was negative (normal) in eight adrenal masses. All these lesions were benign as proven by biopsy (n = 2) and CT attenuation values of less than 10 H (n = 6). The mean standardized uptake ratio value for these eight lesions classified as benign was 1.77 (range, 0.93-3.70). The sensitivity for detecting metastatic disease was 100%, and the specificity was 80%., Conclusion: PET with FDG is an accurate, noninvasive way to differentiate benign from metastatic adrenal masses in patients with bronchogenic carcinoma.

Purpose: To assess the role of positron emission tomographic (PET) imaging with 18-fluoro-2-deoxyglucose (18FDG) in detecting thoracic lymph node metastases in patients with bronchogenic carcinoma., Materials and Methods: Over a 2-year period, any patient presenting to our institution with newly diagnosed bronchogenic carcinoma who was to have thoracic nodes sampled was considered eligible. All PET studies were performed prior to nodal sampling and areas of increased uptake were mapped according to the American Thoracic Society classification. Studies were correlated with CT and pathology. Sensitivity and specificity for predicting nodal metastases was calculated., Results: Forty-two patients had 62 nodal stations (40 hilar/lobar, 22 mediastinal) sampled. The sensitivity and specificity for hilar/lobar lymph node station metastases using PET imaging was 73% and 76%, respectively. With CT, the sensitivity and specificity were 27% and 86%. The sensitivity and specificity using PET imaging for mediastinal node station metastases was 92% and 100%, respectively, while with CT the figures were 58% and 80%. The sensitivity and specificity for combined thoracic nodal station metastases using PET imaging was 83% and 82%, respectively, while with CT it was 43% and 85%. There was a strong statistical relationship between positive PET imaging and lymph node abnormalities., Conclusions: 18FDG-PET imaging is accurate in detecting thoracic lymph node metastases in patients with bronchogenic carcinoma. Normal results of PET studies virtually preclude the need for mediastinal nodal sampling prior to surgery, whereas abnormal results of studies most likely represent mediastinal metastases. Treatment can be based on the extent of disease suggested by PET imaging.

Background: The growth rate, or doubling time, of radiographically indeterminate pulmonary abnormalities is an important determinant of malignancy. Prospective calculation of doubling time, however, delays diagnosis and treatment. Positron emission tomography (PET) using the glucose analogue fluoride-18 fluorodeoxyglucose (FDG) measures the enhanced glucose uptake characteristic of neoplastic cells. We postulated that if FDG activity correlates with doubling time, then PET may allow prompt diagnosis of lung cancer., Methods: From March 1992 to July 1993, all patients with indeterminate focal pulmonary abnormalities were eligible for FDG PET imaging. In 53 patients, serial chest radiographs or computed tomograms were available and doubling time was computed. The FDG activity within the lesion was expressed as a standardized uptake ratio., Results: The mean standardized uptake ratio (+/- SD) was 5.9 +/- 2.7 in 34 patients with cancer, versus 2.0 +/- 1.7 in 19 with benign disease (p < 0.001). Using a criterion of standardized uptake ratio 2.5 or greater for malignancy, the accuracy of PET was 92% (49 of 53). The standardized uptake ratio was significantly correlated with doubling time (r = -0.89; p = 0.002)., Conclusion: These data suggest a direct relation between tumor growth and FDG uptake in lung cancer. The technique of FDG PET demonstrates exceptional accuracy and may permit prompt diagnosis of lung cancer.

Positron emission tomography (PET), with the glucose analog F-18 fluoro-deoxyglucose (FDG), takes advantage of the enhanced glucose uptake observed in neoplastic cells. We examined whether the detection of preferential FDG uptake with PET permits differentiation between benign and malignant focal pulmonary lesions in patients with suspected primary or recurrent lung cancer. Between November 1991 and September 1993, 100 patients with indeterminate focal pulmonary abnormalities including 16 patients who had previous lung resections for cancer were prospectively studied. Tissue diagnosis was obtained by transbronchial or percutaneous biopsy (n = 49) and open biopsy or resection (n = 35). Three patients underwent extended observation (> 2 years) alone. Excluded were 13 patients lacking firm pathologic diagnoses and less than 2-year follow-up. FDG activity in the lesion was expressed as a calculated standardized uptake ratio. Mean standardized uptake ratio (+/- standard deviation) was 6.6 (+/- 3.1) in 59 patients with cancer versus 2.0 (+/- 1.6) in 28 with benign disease (p = 0.0001; unpaired t test, two-sided). With a standardized uptake ratio > or = 2.5 used for detecting malignancy, sensitivity, specificity, and accuracy were 97% (57/59), 82% (23/28), and 92% (80/87), respectively. Notably, in patients evaluated for pulmonary abnormalities after lung resection for cancer, all chest recurrences were correctly identified. The exceptional sensitivity of FDG PET demonstrates that malignant pulmonary lesions preferentially accumulate FDG, which results in a standardized uptake ratio > or = 2.5. PET may be useful for distinguishing recurrent tumor from postoperative, or postradiation, changes. If performed in all patients before open biopsy, PET increases the diagnostic yield by reducing the number of patients who have benign lesions at operation. Moreover, by lowering expenditures for hospitalization and other diagnostic procedures, FDG PET may significantly reduce health care costs.

Positron emission tomography (PET) is just beginning to emerge as a clinically useful tool in the thorax. Imaging with FDG is used primarily to differentiate benign from malignant abnormalities, including solitary pulmonary nodules, staging bronchogenic carcinoma, and differentiating recurrent tumor from fibrosis following treatment. This article discusses the fundamental properties of PET images, techniques, and current clinical indications in the thorax.

Purpose: To assess positron emission tomography (PET) with 2-[fluorine-18]-2-deoxy-D-glucose (FDG) in the differentiation of recurrent bronchogenic carcinoma from fibrosis after therapy., Materials and Methods: Any patient treated for bronchogenic carcinoma who had a residual chest radiographic abnormality was eligible. Forty-three patients (mean age, 63.5 years) participated. Chest radiographs and thoracic computed tomographic scans helped localize the abnormality prior to PET. Semiquantitative analysis was performed on FDG PET images with calculated standardized uptake ratios (SURs). Sensitivity, specificity, and confidence intervals for recurrent disease were determined., Results: Thirty-five patients had recurrent or persistent tumor (median SUR, 7.6; range, 1.9-18.7). Eight patients had fibrosis but no evidence of disease (SUR, 1.6; range, 0.6-2.4). The sensitivity for detecting recurrent tumor (SUR > 2.5) was 97.1%, and specificity was 100%. The SUR for recurrent tumor was statistically significantly higher than for fibrosis (P = .0001)., Conclusion: FDG PET accurately helps differentiate recurrent bronchogenic carcinoma from fibrosis.

The authors assessed the role of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) in differentiation of benign from malignant focal pulmonary abnormalities seen on chest radiographs. Fifty-one patients underwent FDG PET scanning. Focal abnormalities at radiography included solitary pulmonary nodules (n = 38), pulmonary masses (n = 5), and poorly marginated infiltrates or opacities (n = 8). Proof of diagnosis was obtained by means of transbronchial biopsy (n = 21), open lung biopsy (n = 14), percutaneous needle biopsy (n = 14), or cytologic evaluation of sputum (n = 1). A nodule in one patient had been radiographically stable for at least 8 years. Quantitative analysis was performed by calculation of a standardized uptake ratio (SUR). Thirty-three malignant lesions had a mean SUR (+/- 1 standard deviation) of 6.5 +/- 2.9. Eighteen benign lesions had a mean SUR of 1.7 +/- 1.2. For a benign lesion with SUR of 2.5 or less, specificity of FDG PET was 100%, while sensitivity was 89%. These results suggest that FDG PET is accurate in differentiation of benign from malignant focal pulmonary abnormalities.