Lymph node staging for urinary bladder carcinoma with positron emission tomography (PET)

PET is a new method in nuclear medicine which examines the metabolism and not the morphology. Tumors show a higher rate of glycolysis than benign tissue and hence can be detected by radioactive glucose. This method has proved good for various tumors. In this study the lymph node staging of bladder cancer by PET was investigated. In 64 patients a PET of the pelvis after injection of fluorodeoxyglucose (FDG) was carried out preoperatively; the PET-results were compared with the histology of the OR specimen after classical pelvic lymphadenectomy. For lymph node staging positive nodes were found in 14 patients which was correct; a false-negative result was obtained in 7 patients. In 37 patients the PET-result was true-negative and in 6 patients false-positive resulting in a sensitivity of 67 %, a specificity of 86 % and an accuracy of 80 %. Therefore, our PET results are encouraging and seem to be better than those obtained by classical staging procedures such as CT or MRI.     

Lymph node staging for urinary bladder carcinoma with positron emission tomography (PET)

Summary PET is a new method in nuclear medicine which examines the metabolism and not the morphology. Tumors show a higher rate of glycolysis than benign tissue and hence can be detected by radioactive glucose. This method has proved good for various tumors. In this study the lymph node staging of bladder cancer by PET was investigated. In 64 patients a PET of the pelvis after injection of fluorodeoxyglucose (FDG) was carried out preoperatively; the PET-results were compared with the histology of the OR specimen after classical pelvic lymphadenectomy. For lymph node staging positive nodes were found in 14 patients which was correct; a false-negative result was obtained in 7 patients. In 37 patients the PET-result was true-negative and in 6 patients false-positive resulting in a sensitivity of 67 %, a specificity of 86 % and an accuracy of 80 %. Therefore, our PET results are encouraging and seem to be better than those obtained by classical staging procedures such as CT or MRI.      

Value of [18F]-fluorodeoxyglucose (FDG) positron emission tomography in digestive cancerology

COLORECTAL CANCERS: FDG-PET is a very effective tool in the follow-up of colorectal cancer for the early detection of recurrences, the search for other localisations in case of resectable lesions and for the evaluation of therapies. For the other digestive cancers, the data in the literature are less abundant and they do not yet have Marketing Authorization in France. OESOPHAGEAL CANCER: FDG-PET appears very promising for staging and detection of recurrences of oesophageal carcinomas. Pancreatic cancer Although the indication is difficult, FDG-PET appears superior to morphological techniques for the characterization and the locoregional staging of pancreatic tumours. BILARY AND GASTRIC CARCINOMAS: FDG-PET is promising but its role has to be confirmed in larger series for the detection of biliary and gastric carcinomas. OTHER DIGESTIVE TUMOURS: In cases of hepatocarcinoma, FDG-PET appears efficient only in cases of undifferentiated tumours, and in cases of malignant neuroendocrine digestive tumours, is useful in combination with somatostatin receptor imaging.     

Pulmonary aspergillosis: an alternative diagnosis to lung cancer after positive [18F]FDG positron emission tomography

[(18)F]Fluorodexyglucose (FDG) positron emission tomography (PET) scans have significantly improved the diagnosis and staging of lung cancer, but false-positive scans are known to occur due to inflammatory and infectious diseases. Recognition of the conditions leading to false-positive scans is important. Single or multiple pulmonary nodules, with or without cavitation, are classical findings in acute and chronic pulmonary aspergillosis. Clinical features of pulmonary aspergillosis are very similar to those of lung cancer. This report highlights pulmonary aspergillosis as an alternative diagnosis to lung cancer in patients with positive [(18)F]FDG PET scans and the need to strive for presurgical histological diagnosis.     

Comparative efficacy of positron emission tomography with FDG and computed tomographic scanning in preoperative staging of non-small cell lung cancer

OBJECTIVE: To determine the sensitivity, specificity, and accuracy of positron emission tomography with 2-fluorine-18-fluorodeoxyglucose (PET-FDG) in the preoperative staging (N and M staging) of patients with lung cancer. The authors wanted to compare the efficacy of PET scanning with currently used computed tomography (CT) scanning. MATERIALS AND METHODS: Results of whole-body PET-FDG imaging and CT scans were compared with histologic findings for the presence or absence of lymph node disease or metastatic sites. Sampling of mediastinal lymph nodes was performed using mediastinoscopy or thoracotomy. RESULTS: PET-FDG imaging was significantly more sensitive, specific, and accurate for detecting N disease than CT. PET changed N staging in 35% and M staging in 11% of patients. CT scans helped in accurate anatomic localization of 6/57 PET lymph node abnormalities. CONCLUSION: PET-FDG is a reliable method for preoperative staging of patients with lung cancer and would help to optimize management of these patients. Accurate lymph node staging of lung cancer may be ideally performed by simultaneous review of PET and CT scans.     

Advantages of positron emission tomography over computed tomography in mediastinal staging of non-small cell lung cancer

BACKGROUND: New treatment algorithms in early stage non-small cell lung cancer (NSCLC) involving preoperative chemotherapy require accurate clinical staging of the mediastinum. This study compares the accuracy of 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) scanning with that of computed tomography (CT) scanning in the clinical staging of non-small cell lung cancer. MATERIALS AND METHODS: A retrospective review was performed on 52 patients with NSCLC who were evaluated with both CT and PET scans. All patients had their mediastinal lymph nodes sampled by mediastinoscopy or at the time of thoracotomy for pulmonary resection. Each imaging study was evaluated separately and correlated with histopathologic results. RESULTS: For detecting mediastinal metastases the sensitivities of PET and CT scans were 67 and 50%, respectively; specificities were 91 and 65%, respectively; accuracies were 88 and 63%, respectively; positive predictive values were 50 and 16%, respectively; negative predictive values were 95 and 88%, respectively. PET scans were significantly better than CT scans at detecting mediastinal metastases (PET, 4/8; CT, 3/19) (P = 0.01). CONCLUSIONS: PET scanning is superior to CT scanning for clinical staging of the mediastinum in NSCLC. A more confident decision regarding stratification of patients into current treatment algorithms can be made when the decision is based on PET scanning rather than the current "gold standard" of CT scanning.     

(18)F]Fluorodeoxyglucose positron emission tomography and its prognostic value in lung cancer.

OBJECTIVE: Positron emission tomography (PET) is being increasingly used as an accurate and non-invasive modality in diagnosis, staging and post-therapy assessment in patients with lung cancer. In this study, we examine whether the uptake of [(18)F]fluorodeoxyglucose (FDG), a marker of increased glucose metabolism in neoplastic cells, is of prognostic value in patients with primary lung cancer. METHODS: We have retrospectively analyzed 77 patients (mean age, 63. 0 years; male/female ratio, 53:24) with primary lung cancers who underwent whole body and localized thoracic PET as part of their diagnostic and staging procedures prior to consideration of surgical resection. The standardized uptake value (SUV) of injected FDG for each primary lesion was correlated with tumour histology and the patient's clinical outcome. RESULTS: A SUV of 20 or greater was found to be of significant prognostic value. The chance of survival (with 95% confidence intervals (CI)) at 12 months post-surgery for the various SUV groups was as follows: 75.2% (59.6-85.5) for SUV<10; 67.5% (29.0-88.2) for SUV 10-<12; 63.6% (29.7-84.5) for SUV 12-<15; 66.7% (19.5-90.4) for SUV 15-<20; 16.7% (0.01-0.52) for SUV>20. A SUV of 20 or more is associated with a 4.66 times increase in hazard, compared with lower levels of SUV. We found no significant correlation between tumour histology and SUV. CONCLUSION: We have previously reported on the significant advantages of PET in the staging and surgical care of patients with lung cancer. The present study adds further support for an additional prognostic role for PET in the management of thoracic malignancy as determined by the amount of labelled-FDG taken up by the primary lesion.     

Role of positron emission tomography in mediastinal lymphatic staging of non-small cell lung cancer.

OBJECTIVE: Positron emission tomography (PET) is used increasingly in staging of non-small cell lung cancer (NSCLC) as a non-invasive tool. The role of the PET in mediastinal lymphatic staging of NSCLC is not clear. We aimed to demonstrate the efficacy of PET in determining mediastinal lymphatic metastasis by comparing the results of PET with mediastinoscopy. PATIENTS AND METHODS: We performed PET preoperatively in 170 patients with clinically operable NSCLC between 2004 and 2006. Stations defined as metastasis by PET (SUV(max) >2.5) were recorded. Mediastinoscopy was performed initially in all patients and a total of 687 stations which can be reached with mediastinoscope were sampled (mean 4.04). Forty-three patients with mediastinal metastasis were referred to the oncology clinic for chemotherapy while lung resection and complete mediastinal lymphatic dissection through thoracotomy was performed in the remaining 127 patients. Involvement of mediastinal lymph nodes was verified to compare the sensitivity and specificity of mediastinoscopy and the related PET results. RESULTS: Histopathologic classification of the tumors revealed 79 squamous carcinomas and 58 adenocarcinomas. False positivity rate of PET was 26% (95% CI: 14-38), false negativity was 25% (95% CI: 18-33), sensitivity was 74% (95% CI: 63-86), specificity was 73% (95% CI: 66-82) and accuracy was 74% in mediastinal staging. Negative predictive value of mediastinoscopy was 94% (95% CI: 89-98), positive predictive value 100%, sensitivity 84% (95% CI: 74-94), specificity 100% and accuracy was 95%. CONCLUSION: PET results do not provide acceptable accuracy rates. Mediastinoscopy still remains the gold standard for mediastinal staging of NSCLC, although it cannot reach to all the mediastinal stations.     

F-18]-fluorodeoxyglucose (FDG) positron emission tomography (PET) as a diagnostic for hip endoprosthesis loosening

AIM: The purpose of this study was to examine the FDG-PET in respect of its diagnostic valency with regard to septic/aseptic loosening of lower limb prostheses. METHOD: 28 patients with 41 lower limb prostheses were examined by means of FDG-PET to evaluate septic/aseptic loosening of their hip prostheses. Therefore, a differentiated FDG-PET result interpretation subdivided into five categories was developed. The final diagnosis was based on operative findings with following culture and histological outcome. RESULTS: The worked-out categories showed a high agreement to the intraoperative macroscopic and histological results (n = 23 correctly positive, n = 1 false positive, n = 1 correctly negative and n = 3 false negative). CONCLUSION: With a subtly differentiated interpretation (categories I - V) of the qualitative glucose metabolism safe statements can be made regarding septic/aseptic endoprostheses loosening. This was impressively confirmed by the agreement of the FDG results with the histological results.     

Detection of mediastinal lymph node metastasis from lung cancer with positron emission tomography (PET) using 11C-methionine]

Twenty-five patients with primary non-small cell lung cancer underwent the positron emission tomography (PET) using 11C-methionine to detect the mediastinal lymph node metastasis. We introduced the positron angiography to recognize precisely the anatomical orientation of the mediastinal lymph nodes. The 11C-uptake of the lymph node was expressed with distribution absorption ratio (DAR). A total 107 lymph nodes were examined. The average DAR in metastatic lymph nodes (n = 28) was 3.89 while that of non-metastatic nodes (n = 79) was 2.38 indicating a significant difference (p < 0.001). The most adequate threshold for detection of metastasis was 3.3 with sensitivity of 100%, and specificity of 87.3% and overall accuracy of 89.7%. Metastasis of squamous cell carcinoma was diagnosed more accurately than that of adenocarcinoma. Thus, PET using 11C-methionine may offer a new method to detect the mediastinal lymph node metastasis from lung cancer.     

Factors causing inaccurate staging of mediastinal nodal involvement in non-small cell lung cancer patients staged by positron emission tomography

Despite documented superiority of positron emission tomography over other investigative modalities in the preoperative staging of non-small cell lung cancer, a proportion of patients will have an inaccurate staging of their mediastinal nodes. The aim of this retrospective review is to analyse the clinicopathological factors responsible for inaccurate nodal staging by integrated PET-CT. A total of 100 consecutive patients with histologically proven non-small cell lung cancer underwent staging with PET-CT prior to lung resection. Thirty-three patients, inaccurately staged by PET-CT, were analysed. Univariate analysis identified the following as significant in causing inaccurate nodal staging: history of tuberculosis (P=0.039) and non-insulin dependant diabetes (P=0.014). In multivariate analysis, we have identified the following as independent factors in causing inaccurate staging of mediastinal lymph nodes: rheumatoid arthritis, non-insulin dependent diabetes, history of tuberculosis, presence of atypical adenomatous hyperplasia and pneumonia (P<0.05). The highest rate of inaccuracy in mediastinal nodal staging was in nodal station 4 (11%, P=0.01) followed by station 7 (10%, P=0.02) and station 9 (3.5%, P=0.01). Interpretation of PET-CT staging of the mediastinum in patients with a history of the above should be with caution, as the incidence of false upstaging and down staging in these subgroups is high. Vigilance of such factors may improve the accuracy of PET-CT in staging mediastinal lymph nodes. Histological confirmation should always be sought.     

Prognostic significance of preoperative [18-F] fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging in patients with resectable soft tissue sarcomas

OBJECTIVE: The objective of this study was to evaluate the prognostic significance of preoperative positron emission tomography (PET) using 2-fluoro-2-deoxy-D-glucose (FDG) by calculating the mean standardized uptake values (SUV) in patients with resectable soft tissue sarcomas (STS). SUMMARY AND BACKGROUND DATA: FDG-PET might be used as an adjunctive tool (in addition to biopsy and radiologic tomography) in the preoperative prognostic assessment of resectable STS. METHODS: A total of 74 adult patients with STS underwent preoperative FDG-PET imaging with calculation of the SUV. Clinicopathologic data and the SUV were analyzed for an association with the clinical outcome. The first and the third quartiles of the SUV distribution function were used as cutoff values (1.59 and 3.6). Survival was estimated by the Kaplan-Meier method. Univariate and multivariate analyses were performed using log-rank test and the Cox proportional hazards regression model. RESULTS: In 55 cases, STS were completely resected (follow up 40 months): 5-year recurrence-free survival rates in patients with SUV <1.59, 1.59 to <3.6, and > or =3.6 were 66%, 24%, and 11%, respectively (P = 0.0034). SUV was a predictor for overall survival (5-year rates: 84% [SUV <1.59], 45% [SUV 1.59 to <3.6], and 38% [SUV > or =3.6]; P = 0.057) and local tumor control (5-year rates: 93% [SUV <1.59], 43% [SUV 1.59 to <3.6], and 15% [SUV > or =3.6]; P = 0.0017). By multivariate analysis, SUV was found to be predictive for recurrence-free survival. The prognostic differences with respect to the SUV were associated with tumor grade (P = 0.002). CONCLUSION: The semiquantitative FDG uptake, as measured by the mean SUV on preoperative PET images in patients with resectable STS, is a useful prognostic parameter. SUV with cutoff values at the first and the third quartiles of the SUV distribution predicted overall survival, recurrence-free survival, and local tumor control. Therefore, FDG-PET can be used to improve the preoperative prognostic assessment in patients with resectable STS.     

Mediastinal lymph node staging in suspected lung cancer: comparison of positron emission tomography with F-18-fluorodeoxyglucose and mediastinoscopy

BACKGROUND: In patients with bronchogenic carcinoma, mediastinal lymph node staging is essential for determining treatment options. In this retrospective analysis we compared the results of positron emission tomography (PET) using F-18 fluorodeoxyglucose with those of mediastinoscopy in nodal staging for suspected bronchogenic carcinoma. METHODS: From March 1997 to June 2001, 102 patients (86 male,16 female, age 62 +/- 9 years) underwent both PET and mediastinoscopy for radiologically suspected mediastinal lymph node disease in bronchogenic carcinoma. Total body emission scans were acquired 90 to 150 minutes after injection of 230 MBq of F-18 fluorodeoxyglucose. Mediastinoscopic evaluation of lymph node stations was performed according to the method of Mountain and Dresler (1R, 1L, 2L, 2R, 4L, 4R,7). Patients were eligible if surgical staging was performed within 6 weeks after the PET scan. RESULTS. Of the 102 patients, benign lesions were diagnosed in 15. In 87 patients malignant disease was proven by histology, and bronchogenic carcinoma was found in 82. Of 469 nodal stations analyzed, malignancy was documented by histology in 84. In PET analysis 79 true-positive and 304 true-negative samples were found. Five lymph node stations were false negative, and 81 samples were false positive. False-positive findings in PET frequently were seen in inflammatory lung disease. The sensitivity of PET was 94.1%, specificity was 79% with a diagnostic accuracy of 81.6%. The positive predictive value of PET was 49.3%, and the negative predictive value was 98.4%. CONCLUSIONS: In patients with positive PET scan results histologic verification appears necessary for exact lymph node staging. In view of the negative predictive value mediastinoscopy can be omitted in patients with bronchogenic carcinoma whose PET scan results were negative.     

Prospective use of serial questionnaires to evaluate the therapeutic efficacy of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in suspected lung cancer

BACKGROUND: A study was undertaken to study the effect of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) on the diagnosis and management of clinically problematic patients with suspected non-small cell lung cancer (NSCLC). METHODS: A prospective before-after study was performed in a cohort of all 164 patients (university/community settings) referred for PET between August 1997 and July 1999. PET was restricted to cases where non-invasive tests had failed to solve clinical problems. The impact on diagnostic understanding and management was assessed using questionnaires (intended treatment without PET, actual treatment choice after PET, post hoc clinical assessment). RESULTS: Diagnostic problems especially pertained to unclear radiological findings (n=112; 63%), mediastinal staging (n=36; 20%), and distant staging issues (n=16; 9%). PET findings were validated by reviewing medical records. PET had a positive influence on diagnostic understanding in 84%. Improved diagnostic understanding solely based on PET was reported in 26%. According to referring physicians, PET resulted in beneficial change of treatment in 50%. Cancelled surgery was the most frequent change in treatment after PET (35%). CONCLUSION: FDG PET applied as "add on" technology in patients with these clinical problems appears to be a clinically useful tool, directly improving treatment choice in 25% of patients. The value of increased confidence induced by PET scanning requires further evaluation.