Integrated FDG-PET/CT does not make invasive staging of the intrathoracic lymph nodes in non-small cell lung cancer redundant: a prospective study

BACKGROUND: Staging of non-small cell lung cancer (NSCLC) is important for determining choice of treatment and prognosis. The accuracy of FDG-PET scans for staging of lymph nodes is too low to replace invasive nodal staging. It is unknown whether the accuracy of integrated FDG-PET/CT scanning makes invasive staging redundant. METHODS: In a prospective study, the mediastinal and/or hilar lymph nodes in patients with proven NSCLC were investigated with integrated FDG-PET/CT scanning. Pathological confirmation of all suspect lymph nodes was obtained to calculate the accuracy of the fusion images. In addition, the use of the standardised uptake value (SUV) in the staging of intrathoracic lymph nodes was analysed. RESULTS: 105 intrathoracic lymph node stations from 52 patients with NSCLC were characterised. The prevalence of malignancy in the lymph nodes was 36%. The sensitivity of the integrated FDG-PET/CT scan to detect malignant lymph nodes was 84% and its specificity was 85% (positive likelihood ratio 5.64, negative likelihood ratio 0.19). SUV(max), SUV(mean) and the SUV(max)/SUV(liver) ratio were all significantly higher in malignant than in benign lymph nodes. The area under the receiver operating curve did not differ between these three quantitative variables, but the highest accuracy was found with the SUV(max)/SUV(liver) ratio. At a cut-off value of 1.5 for the SUV(max)/SUV(liver )ratio, the sensitivity and specificity to detect malignant lymph node invasion were 82% and 93%, respectively. CONCLUSION: The accuracy of integrated FDG-PET/CT scanning is too low to replace invasive intrathoracic lymph node staging in patients with NSCLC. The visual interpretation of the fusion images of the integrated FDG-PET/CT scan can be replaced by the quantitative variable SUV(max)/SUV(liver) without loss of accuracy for intrathoracic lymph node staging.     

Lymph node staging in non-small cell lung cancer: evaluation by [18F]FDG positron emission tomography (PET)

BACKGROUND: A study was undertaken to investigate the accuracy of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D- glucose (FDG) in the thoracic lymph node staging of non-small cell lung cancer (NSCLC). METHODS: Forty six patients with focal pulmonary tumours who underwent preoperative computed tomographic (CT) and FDG- PET scanning were evaluated retrospectively. Thirty two patients had NSCLC and 14 patients had a benign process. The final diagnosis was established by means of histopathological examination at thoracotomy, and the nodal classification in patients with lung cancer was performed by thorough dissection of the mediastinal nodes at surgery. RESULTS: FDG-PET was 80% sensitive, 100% specific, and 87.5% accurate in staging thoracic lymph nodes in patients with NSCLC, whereas CT scanning was 50% sensitive, 75% specific, and 59.4% accurate. The absence of lymph node tumour involvement was identified by FDG-PET in all 12 patients with NO disease compared with nine by CT scanning. Lymph node metastases were correctly detected by FDG-PET in three of five patients with N1 disease compared with two by CT scanning, in nine of 11 with N2 disease compared with six by CT scanning, an in all four with N3 nodes compared with two by CT scanning. CONCLUSIONS: FDG-PET provides a new and effective method for staging thoracic lymph nodes in patients with lung cancer and is superior to CT scanning in the assessment of hilar and mediastinal nodal metastases. With regard to resectability, FDG-PET could differentiate reliably between patients with N1/N2 disease and those with unresectable N3 disease.     

The size of mediastinal lymph nodes and its relation with metastatic involvement: a meta-analysis.

Positron emission tomography with 18-fluorodeoxyglucose (FDG-PET) seems to be superior to computed tomography (CT) in staging the mediastinum in patients with non-small-cell lung cancer (NSCLC). However, recent results suggest that FDG-PET performance characteristics are conditional for nodal size as shown by CT: FDG-PET is more sensitive but less specific with lymph node enlargement on CT. The association between size and the probability of malignancy needs to be known to predict the post-test probabilities after PET, and finally, stratify patients for mediastinoscopy or thoracotomy depending on the PET and CT results. Therefore, we performed a meta-analysis of available studies reporting on the prevalence of metastatic involvement for different size categories of enlarged lymph nodes in patients with NSCLC and were able to include 14 studies. The prevalence of metastatic involvement and conditional test performance of CT and FDG-PET were calculated for lymph nodes measuring 10-15 mm, 16-20 mm and >20 mm. We found a post-test probability for N2 disease of 5% for lymph nodes measuring 10-15 mm on CT in patients with a negative FDG-PET result, suggesting that these patients should be planned for thoracotomy because the yield of mediastinoscopy will be extremely low. For patients with lymph nodes measuring > or =16 mm on CT and a negative FDG-PET result a post-test probability for N2 disease of 21% was found, suggesting that these patients should be planned for mediastinoscopy prior to possible thoracotomy to prevent too many unnecessary thoracotomies in this subset.     

Histopathologic validation of lymph node staging with FDG-PET scan in cancer of the esophagus and gastroesophageal junction: A prospective study based on primary surgery with extensive lymphadenectomy

OBJECTIVE: To assess the value of positron emission tomography with 18fluorodeoxyglucose (FDG-PET) for preoperative lymph node staging of patients with primary cancer of the esophagus and gastroesophageal junction. SUMMARY BACKGROUND DATA: FDG-PET appears to be a promising tool in the preoperative staging of cancer of the esophagus and gastroesophageal junction. Recent reports indicate a higher sensitivity and specificity for detection of stage IV disease and a higher specificity for diagnosis of lymph node involvement compared with the standard use of computed tomography and endoscopic ultrasound. METHODS: Forty-two patients entered the prospective study. All underwent attenuation-corrected FDG-PET imaging of the neck, thorax, and upper abdomen, a spiral computed tomography scan, and an endoscopic ultrasound. The gold standard consisted exclusively of the histology of sampled nodes obtained by extensive two-field or three-field lymphadenectomies (n = 39) or from guided biopsies of suspicious distant nodes indicated by imaging (n = 3). RESULTS: The FDG-PET scan had lower accuracy for the diagnosis of locoregional nodes (N1-2) than combined computed tomography and endoscopic ultrasound (48% vs. 69%) because of a significant lack of sensitivity (22% vs. 83%). The accuracy for distant nodal metastasis (M+Ly), however, was significantly higher for FDG-PET than the combined use of computed tomography and endoscopic ultrasound (86% vs. 62%). Sensitivity was not significantly different, but specificity was greater (90% vs. 69%). The FDG-PET scan correctly upstaged five patients (12%) from N1-2 stage to M+Ly stage. One patient was falsely downstaged by FDG-PET scanning. CONCLUSIONS: FDG-PET scanning improves the clinical staging of lymph node involvement based on the increased detection of distant nodal metastases and on the superior specificity compared with conventional imaging modalities.     

Staging of non-small cell lung cancer: clinical value of positron emission tomography and mediastinoscopy

We report about a MEDLINE research from 2000 to 2005 with the key words 'positron emission tomography AND/OR mediastinoscopy'. The search identified 448 potential studies. Out of the published data sensitivity, specificity, positive and negative predictive value, and accuracy for mediastinal lymph node staging by FDG-PET ranged from 58%-94%, 76%-96%, 43%-95%, 56%-98% to 74%-91%, respectively. With corresponding values of 80%-96%, 100%, 100%, 92%-97%, and 94%, respectively, for mediastinoscopy. FDG-PET improved the rate of detection of local and distant metastases in 12% to 62% and changed the management of treatment in 8% to 60% of patients with NSCLC. Our study shows that in the diagnostic strategy of patients with NSCLC, additional FDG-PET can prevent non-therapeutic thoracotomy in a significant number of cases. If FDG-PET imaging and CT scan is negative for mediastinal lymph node involvement routinely mediastinoscopy can be omitted and thoracotomy can immediately be performed. In patients with negative FDG-PET scan, but positive CT scan, histologic verification by invasive methods can individually be considered. Patients with positive FDG-PET scan mediastinoscopy still remain a reliable standard for exact lymph node staging. By incorporating FDG-PET in clinical staging unnecessary exploratory thoracotomies, and mediastinoscopy, can be omitted.     

Impact of 18F-FDG PET/CT on the Treatment of Patients With Non-Small Cell Lung Cancer

IntroductionDisease stage is the most important prognostic factor in lung cancer, and optimal staging is important to determine the best therapeutic option. FDG-PET/CT has demonstrated its value in the treatment of early stage non-small cell lung cancer (NSCLC), but there is still insufficient data to define its role in other stages.HypothesisInformation provided by FDG-PET/CT has an impact on the therapeutic management of patients with NSCLC.MethodsA retrospective review was made of patients who underwent FDG-PET/CT between January 2008 and December 2010 for the diagnosis of NSCLC. Clinical stage before and after FDG-PET/CT and information about any change in therapeutic decision due to information provided by FDG-PET/CT were collected. Using pathologic evaluation as the gold standard, sensitivity, specificity, and positive and negative predictive values for CT and FDG-PET/CT were calculated.ResultsOf the 522 patients diagnosed of NSCLC, FDG-PET/CT was performed in 246 patients (47.1%). In 85 cases (34.6%) FDG-PET/CT led to stage migration. Treatment was modified in 60 patients (24.4% of all FDG-PET/CT performed), avoiding a futile thoracotomy in 13 cases (5.2%), and allowing treatment with curative intent in 26 (10.5%). Of 90 patients (36.5%) evaluated as stage iii by CT staging, FDG-PET/CT modified the therapeutic approach in 36 (40%). For 133 cases (54%) with pathological assessment of the mediastinal lymph nodes, sensitivity, specificity, positive predictive value and negative predictive value were 0.57, 0.64, 0.48 and 0.72 for CT, and 0.68, 0.86, 0.75 and 0.81 for FDG-PET/CT.DiscussionOur data support previous reports that FDG-PET/CT is essential in the staging process not only for patients with potentially operable NSCLC, but also for stage iii patients, as demonstrated by our data.     

Detecting metastatic pelvic lymph nodes by 18F-2-deoxyglucose positron emission tomography in patients with prostate-specific antigen relapse after treatment for localized prostate cancer

AIM: To evaluate whether positron emission tomography (PET) with (18)F-2-deoxyglucose (FDG) can detect pelvic lymph node metastases in prostate cancer patients who had elevated serum prostate-specific antigen (PSA) levels after treatment. METHODS: Twenty-four patients with a rising serum PSA level after treatment for localized prostate cancer were examined with FDG-PET before pelvic lymph node dissection. All patients had negative findings on whole body bone scan and equivocal pelvic computed tomography (CT) results. The results of FDG-PET were then compared to the histology of the pelvic lymph nodes obtained at surgery. RESULTS: Lymph node metastases were detected by histopathological examination in 16/24 (66.7%) patients. At the sites with histopathologically proven metastases, increased FDG uptake was found in 12/16 (75.0%) patients. In addition, there were 4 patients with false-negative results, but no patient with a false-positive result on FDG-PET images. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG-PET in detecting metastatic pelvic lymph nodes were 75.0, 100.0, 83.3, 100.0, and 67.7%, respectively. CONCLUSIONS: These results suggest that FDG-PET may be a valuable diagnostic tool in the staging of pelvic lymph nodes in patients with PSA relapse after treatment of localized prostate cancer when the whole body bone scan is negative and pelvic CT findings are equivocal.     

FDG-PET imaging for lymph node staging and pathologic tumor response after neoadjuvant treatment of non-small cell lung cancer.

PURPOSE: A number of studies have demonstrated that 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is effective for staging of lung cancer. However, the efficacy of FDG-PET for staging lung cancer after neoadjuvant treatment is still controversial. This study compared FDG-PET and computed tomography (CT) for lung cancer staging, and evaluated the ability of the two methods to predict the pathologic response of the primary tumor to neoadjuvant treatment. PATIENTS AND METHODS: Twenty-two patients who underwent neoadjuvant treatment followed by surgery were investigated. Eighteen patients received chemoradiotherapy and four patients received chemotherapy only. One hundred and three lymph node stations in the 22 patients were evaluated by FDG-PET and CT. The pathologic responses of the tumors were compared by FDG-uptake and tumor size on CT for the 15 patients who underwent FDG-PET and CT both before and after neoadjuvant treatment. RESULTS: There was no significant difference in the ability of FDG-PET or CT to predict residual viable tumor. Although positive predictive value by FDG-PET (0.29) was lower than that by CT (0.64) (p=0.04) in the mediastinal lymph nodes, there were no statistically significant differences in the other results of lymph nodes by FDG-PET and CT. Both decrease in FDG-uptake and decrease in tumor size by CT after neoadjuvant treatment correlated significantly with pathologic response in the 15 patients (p=0.003 and 0.009, respectively). CONCLUSION: FDG-PET did not appear to offer any advantages over CT for lymph node staging or for predicting the pathologic response after neoadjuvant treatment of non-small cell lung cancer.     

Endoscopic ultrasound in lung cancer patients with a normal mediastinum on computed tomography

BACKGROUND: Computed tomography (CT) is the most common method of staging lung cancer. We have previously shown endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) to be highly accurate in staging patients with nonsmall cell lung cancer (NSCLC) who have enlarged mediastinal lymph nodes on CT scan. In this study we report the accuracy and yield of EUS-FNA in staging patients without enlarged mediastinal lymph nodes by CT. METHODS: Patients with NSCLC and CT scan showing no enlarged mediastinal lymph nodes (> 1 cm for all nodes except > 1.2 cm for subcarinal) in the mediastinum underwent EUS. Fine needle aspiration was performed on at least one lymph node, if present, in the upper mediastinum, aortopulmonary window, subcarinal, and periesophagus regions. Each specimen was evaluated with on-site cytopathology and confirmed with complete cytopathologic examination. RESULTS: Sixty-nine patients without enlarged mediastinal lymph nodes were evaluated. Endoscopic ultrasound detected malignant mediastinal lymph nodes in 14 of 69 patients as well as other advanced (American Joint Committee on Cancer [AJCC] stage III/IV) in 3 others (1 left adrenal, and 2 with mediastinal invasion of tumor) for a total of 17 of 69 (25%, 95% confidence interval: 16% to 34%) patients. Eleven additional patients were found to have advanced disease by bronchoscopy (2), mediastinoscopy (2), and thoracotomy with mediastinal lymph node dissection (7). The sensitivity of EUS for advanced mediastinal disease was 61% (49% to 75%), and the specificity was 98% (95% to 100%). CONCLUSIONS: Endoscopic ultrasound guided fine needle aspiration can detect advanced mediastinal disease and avoid unnecessary surgical exploration in almost one of four patients who have no evidence of mediastinal disease on CT scan. In addition to previously reported results in patients with enlarged lymph nodes on CT, these data suggest that all potentially operable patients with nonmetastatic NSCLC may benefit from EUS staging.     

Comparison of Integrated Positron Emission Tomography/Computed Tomography and Mediastinoscopy in Mediastinal Staging of Non-Small Cell Lung Cancer: Analysis of 212 Patients

Background : Mediastinal staging is crucial to determine the prognosis and treatment options for patients with non-small cell lung cancer (NSCLC). In this study, we compared the results of integrated positron emission tomography-computerised tomography (PET/CT) with those of mediastinoscopy in mediastinal staging of NSCLC patients. Methods : PET/CT and mediastinoscopy was performed on 250 consecutive patients diagnosed with NSCLC between September 2005 and March 2008. Thirty-eight patients were excluded from the study. Standard cervical mediastinoscopy was performed in all patients, and simultaneous extended cervical mediastinoscopy was performed in 52 patients with left sided lesions. Patients with negative mediastinoscopy underwent resection. The pathological results were correlated with PET/CT findings.

Results : A total of 212 patients (199 male, 13 female; mean age: 58.3 years) were evaluated. In PET/CT analysis 60 true-positive, 45 false-positive, 103 true-negative and 4 false-negative patients were found. The rate of PET/CT positivity of mediastinal lymph nodes was 49.5%. The sensitivity, specificity, positive and negative predictive values and accuracy for PET/CT were 93.8%, 69.6%, 57.1%, 96.3% and 76.9% respectively. The incidence of N2 disease in NSCLC patients with negative mediastinal lymph node uptake on PET/CT was 3.7% (4 of 107). In univariate analysis, right upper lobe tumours were significantly (p < 0.05) more associated with occult N2 disease.

Conclusions : In patients with positive mediastinal lymph node uptake on PET/CT invasive mediastinal staging appears necessary for exact staging. Mediastinoscopy can be omitted in NSCLC patients with negative mediastinal uptake on PET/CT in regions where the rate of PET/CT positivity of mediastinal lymph nodes is high.     

PET-FDG scan enhances but does not replace preoperative surgical staging in non-small cell lung carcinoma.

OBJECTIVE: To assess the effectiveness of positron emission tomography with radiolabeled [18F]-2-fluoro-deoxy-D-glucose (PET-FDG) imaging in mediastinal lymph node (LN) staging for non-small cell lung carcinoma (NSCLC) and to compare it to conventional clinical and surgical staging. METHODS: From June 1998 to February 2000, we enrolled 64 potentially resectable NSCLC patients in a prospective study of PET-FDG imaging of the mediastinum to assess LN involvement. Results of this technique were compared to conventional clinical and surgical staging. Diagnostic efficacy was determined by calculating sensitivity, specificity, overall accuracy, and positive and negative predictive values for each method. RESULTS: PET-FDG imaging correctly identified nodal stage (N0-N1 vs. N2) in 50 out of 61 patients (82%), overstaging occurred in eight patients (13%), and understaging in three patients (4.9%). The sensitivity, specificity, accuracy, and positive and negative predictive values for PET-FDG scan imaging were 67, 85, 82, 43, and 93.6%, respectively. Conventional staging correctly identified nodal stage (N0-N1 vs. N2) in 51 out of 62 patients (82%), overstaging occurred in five patients (8.1%), and understaging in six patients (9.7%). The sensitivity, specificity, accuracy, and positive and negative predictive values for conventional staging were 33, 90.6, 82, 37, and 89%, respectively. With regard to N2 disease, conventional staging showed a poor sensitivity (33%). Indeed, six out of 64 patients were understaged for mediastinal LN involvement. Even though the improvement was not statistically significant (McNemar P=0.08), the combined use of PET-FDG scan and computerized tomography (CT) scan allowed a two-fold increase in the sensitivity of our clinical preoperative staging. Moreover, relying on the PET-scan high negative predictive value might have contributed to a three-fold decrease in the number of required surgical staging procedures. CONCLUSIONS: Our study shows that the PET-FDG imaging strength lies in its very high negative predictive value and increased sensitivity. In this study, the overall accuracy of PET-FDG scan (82%) was lower than previously reported. Combined with chest CT-scan preoperatively, it may alleviate the need for surgical staging when PET-FDG studies of the mediastinum are negative. However, with a positive PET-FDG scan result, further diagnostic procedures should be pursued in order to avoid overstaging and allow better surgical patient selection.     

Can computed tomography of the chest stage lung cancer? Yes and no

To determine the accuracy of computed tomography (CT) of the chest in the staging of lung cancer, we studied 418 patients with primary pulmonary carcinoma between 1979 and 1986. Each had a preoperative scan performed before detailed operative staging. Each CT scan was analyzed for components of the current TNM staging system. Computed tomography sensitivity and specificity for mediastinal lymph node metastasis were 84.4% and 84.1%, with corresponding positive and negative predictive accuracies of 68.7% and 92.9%, respectively. When TNM stages were derived from CT scans, only 190 of 418 (45.4%) completely agreed with operative staging. An additional 53 of 418 (12.7%) predicted the correct stage, although components of the TNM system were incorrect. In 94 of 418 scans (22.5%) CT overestimated the stage, whereas in 81 (19.4%) CT downgraded the stage. Computed tomography suggested metastatic lesions in liver, lung, adrenal gland, bone, or abdominal lymph nodes in 40 of 373 scans (10.7%); only five of 40 (12.5%) had documented metastasis. In summary, CT of the chest cannot accurately stage primary lung carcinoma according to the TNM classification. Because the negative predictive accuracy for mediastinal lymph node metastasis remains high (92.9%), invasive staging can be deferred for definitive thoracotomy when no lymphadenopathy is evident on CT. The high negative predictive accuracy for scans of the chest and upper abdomen makes CT a useful tool for exclusion of metastatic disease.     

Use of positron emission tomography in initial staging of nonsmall cell lung carcinoma: a regional teaching hospital experience

The ability to accurately diagnose mediastinal lymph node involvement is significantly important in patients with nonsmall cell lung cancer (NSCLC). Positron emission tomography (PET) imaging has become a standard technique to assess lymph node involvement in patients with NSCLC. The purpose of this study is to evaluate the accuracy of PET scan imaging as a mediastinal staging tool in patients with NSCLC at our regional teaching institution. We performed a single-institution, retrospective review of patients diagnosed with NSCLC from January 1, 2006, through December 31, 2007. We included only those patients who underwent computed tomography (CT), PET, and pathologic assessment of mediastinal lymph nodes. Using pathologic assessment as the criterion standard, the overall accuracy, sensitivity, specificity, and positive and negative predictive values of CT and PET were calculated. One hundred seventeen patients were identified for inclusion in the study. The overall accuracy was 81.2 per cent for CT and 91.5 per cent for PET. Sensitivity was 42.1 per cent for CT and 52.6 per cent for PET. Specificity was 88.8 per cent for CT and 99.0 per cent for PET. Positive predictive values were 42.1 per cent for CT and 90.9 per cent for PET; negative predictive values were 88.8 per cent for CT and 91.5 per cent for PET. False-negative result rates were 9.4 per cent for CT and 7.7 per cent for PET; false-positive result rates were 9.4 per cent for CT and 0.9 per cent for PET. Our analysis confirms the use of PET scan imaging in the staging of patients with NSCLC at a regional teaching institution.     

F-18-fluorodeoxyglucose positron emission tomography as a presurgical evaluation modality for I-131 scan-negative thyroid carcinoma patients with local recurrence in cervical lymph nodes

BACKGROUND: F-18-labeled fluorodeoxyglucose-positron emission tomography (FDG-PET) has a supplementary role in localizing recurrent sites of differentiated thyroid carcinoma. We evaluated whether FDG-PET is feasible as a presurgical evaluation modality for I-131 scan-negative thyroid carcinoma patients. METHODS: Preoperative FDG-PET results were compared with the pathologic findings of lymph nodes specimens of 22 papillary thyroid patients. All patients had thyroidectomy and I-131 ablation therapy beforehand and showed negative I-131 scans on follow-up studies. RESULTS: In 85 cervical lymph node groups dissected, 56 lymph node groups revealed metastasis. The sensitivity and specificity of FDG PET for metastasis were 80% (45 of 56) and 83% (24 of 29), respectively. Among the pathologically positive 33 lymph nodes with normal size(< or =1 cm), FDG-PET detected 23 nodes. Serum thyroglobulin levels were elevated in 12 patients (sensitivity, 55%). CONCLUSION: FDG-PET accurately detected the recurred cervical lymph nodes of differentiated thyroid carcinoma patients who showed negative I-131 scan. FDG-PET is suitable for the presurgical evaluation of these patients.     

Role of fiberscopic transbronchial needle aspiration in the staging of N2 disease due to non-small cell lung cancer

BACKGROUND: Transbronchoscopic needle aspiration (TBNA) can offer a unique opportunity to identify surgically unresectable lung cancer and to avoid surgical mediastinal exploration in many patients with mediastinal lymph node extension of the tumor. The aim of this study was to assess the yield of TBNA performed with either histology or cytology needles in mediastinal staging of N2 disease due to non-small cell lung cancer (NSCLC). METHODS: Retrospective chart review was carried out on 194 TBNA procedures performed between January 1997 and September 2000 at a single institution. Inclusion criteria were pathologic evidence of NSCLC; contrast enhancement computed tomography scan of the chest suggesting N2 disease; and negative bronchoscopic examination for possible neoplastic lesions at the site of RESULTS: Overall sensitivity and diagnostic accuracy were 71% and 73%, respectively, with no significant differences between 19-gauge and 22-gauge cytology needles. Procedures performed for right paratracheal and subcarinal lymph node stations had a significantly higher yield than those for the left paratracheal station. CONCLUSIONS: TBNA mediastinal staging, performed during the initial diagnostic evaluation of NSCLC, can spare costs and risks of more invasive procedures in patients with inoperable tumors, in patients who are not candidates for operation because of coexistent significant comorbidities, and in patients with N2 disease.     

Preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer: accuracy of integrated positron emission tomography and computed tomography

Objective: To evaluate the accuracy of integrated positron emission tomography with ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) and computed tomography (PET/CT) in preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer (NSCLC) and to ascertain the role of invasive staging in verifying positron emission tomography (PET)/computed tomography (CT) results. Methods: Retrospective, single institution study of consecutive patients with suspected or pathologically proven, potentially resectable NSCLC undergoing integrated PET/CT scanning in the same PET centre. Lymph node staging was pathologically confirmed on tissue specimens obtained at mediastinoscopy and/or thoracotomy. Statistical evaluation of PET/CT results was performed on a per-patient and per-nodal-station bases. Results: A total of 1001 nodal stations (723 mediastinal, 148 hilar and 130 intrapulmonary) were evaluated in 159 patients. Nodes were positive for malignancy in 48 (30.2%) out of 159 patients (N1 = 17; N2 = 30; N3 = 1) and 71 (7.1%) out of 1001 nodal stations (N1 = 24; N2 = 46; N3 = 1). At univariate analysis, lymph node involvement was significantly associated (p < 0.05) with the following primary tumour characteristics: increasing diameter, maximum standardised uptake value >9, central location and presence of vascular invasion. PET/CT staged the disease correctly in 128 out of 159 patients (80.5%), overstaging occurred in nine patients (5.7%) and understaging in 22 patients (13.8%). The overall sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT for detecting metastatic lymph nodes were 54.2%, 91.9%, 74.3%, 82.3% and 80.5% on a per-patient basis, and 57.7%, 98.5%, 74.5%, 96.8% and 95.6% on per-nodal-station basis. With regard to N2/N3 disease, PET/CT accuracy was 84.9% and 95.3% on a per-patient basis and on per-nodal-station basis, respectively. Referring to nodal size, PET/CT sensitivity to detect malignant involvement was 32.4% (12/37) in nodes <10 mm, and 85.3% (29/34) in nodes ≥10 mm. Conclusion: Our data show that integrated PET/CT provides high specificity but low sensitivity and accuracy in intrathoracic nodal staging of NSCLC patients and underscore the continued need for surgical staging.     

Positron Emission Tomography for Staging Esophageal Cancer: Does It Lead to a Different Therapeutic Approach?

Accurate preoperative staging is essential for the indication and selection of the appropriate surgical procedure in patients with esophageal cancer. The present prospective study was designed to determine if the preoperative use of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) increases the accuracy of staging esophageal cancer compared with computed tomography (CT) and if it thereby leads to a different therapeutic approach. A total of 58 patients, 46 men and 12 women (mean age 61 years), with histologic proof of esophageal carcinoma underwent FDG-PET of the neck, chest, and abdomen, as well as CT of the chest and abdomen, to determine tumor stage. FDG-PET and CT data were compared with each other and with pathohistologic findings. Sensitivity, specificity, and overall accuracy for detecting histologically verified lymph node and distant metastases were calculated for FDG-PET and CT. FDG-PET showed a higher specificity, whereas CT had higher accuracy for detecting both abdominal (73% vs. 59%) and thoracic (73% vs. 63%) lymph node metastases. The accuracy of detecting blood-borne and lymphatic distant metastases was identical for CT and FDG-PET imaging (50%). FDG-PET had a higher specificity than CT (87% vs. 13%) but lower sensitivity (35% vs. 67%). FDG-PET did not provide new information on the indication for surgery, nor was it helpful for choosing the appropriate surgical procedure in patients with esophageal carcinoma. In view of the relatively high cost of FDG-PET examinations, the use of this modality is indicated primarily in patients with inconclusive CT findings or for scientific research projects. Higher sensitivity as a result of tumor-affinity radiopharmaceuticals and optimized apparatus resolution, in addition to the advantages offered by whole-body PET scanning, may lead to new indications for this staging procedure in the future.     

The accuracy of integrated PET-CT compared with dedicated PET alone for the staging of patients with nonsmall cell lung cancer

Background

The treatment of patients with nonsmall cell lung cancer (NSCLC) is determined by the stage. We evaluated the accuracy of staging using integrated positron emission tomography (PET) and computed tomography (CT) and compared it with dedicated PET visually correlated with CT scan.

Methods

A prospective blinded trial was performed on a consecutive series of patients with NSCLC. Patients underwent integrated PET-CT scanning with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG-18). A radiologist assigned the T, N and M status. No sooner than 2 weeks the same radiologist read the dedicated PET alone, without the integrated CT images and a T, N and M status was assigned again. The most recent CT scan was available and visually correlated with both studies. All patients underwent biopsies of suspicious N2 or N3 lymph node or distant metastases and if negative, pulmonary resection with lymphadenectomy was performed.

Results

There were 129 patients. Integrated PET-CT is a better predictor than PET for all stages of cancer and achieved statistical significance for stage I (52% versus 33%, p = 0.03) and for stage II (70% versus 36%, p = 0.04). It also is a better overall predictor for T status (70% versus 47%, p = 0.001) and the N status (78% versus 56%, p = 0.008). Nodal analysis shows that integrated PET-CT was more accurate for the total N2 nodes (96% versus 93%, p = 0.01) and for the total N1 nodes (90% versus 80%, p = 0.001). It was also more sensitive, specific, and had a higher positive predictive value for both N2 and N1 nodes (p < 0.05 for all). Integrated PET-CT is significantly more sensitive at the 4R, 5, 7, 10L and 11 stations and more accurate at the 7 and 11 lymph nodes stations than dedicated PET.

Conclusions

Integrated PET-CT using FDG-18 better predicts stage I and II disease as well as the T and N status of patients with NSCLC when compared with dedicated PET alone. It is more accurate at some nodal stations but still only achieves an accuracy of 96% and 90% for the N2 and N1 nodes, respectively.     

Positron emission tomography for preoperative lymph node diagnosis in esophageal carcinoma]

BACKGROUND: Exact preoperative staging is a prerequisite for the indication and the choice of appropriate operative technique for patients with esophageal carcinoma. The objective of this prospective study was to assess whether positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) increases the accuracy of preoperative lymph node staging with standard computed tomography (CT) and thus leads to a different surgical approach. PATIENTS AND METHODS: Fifty-eight patients with carcinoma of the esophagus (46 men and 12 women) with a median age of 61 years underwent FDG-PET imaging of the neck, chest, and abdomen as well as CT of the chest and abdomen. Sensitivity, specificity, and accuracy were calculated for both imaging techniques to evaluate the detection of histologically verified lymph node metastases. RESULTS: The FDG-PET showed higher specificity, whereas CT proved to be more accurate for detecting lymph node metastases not only of the abdomen (73% vs 59%) but also of the thorax (73% vs 63%). Resections were transhiatal in 23 patients and transthoracal in 16. As a supplement to conventional CT diagnostic procedure, FDG-PET was not decisive for the surgical approach. CONCLUSIONS: Altogether, pretherapeutical PET imaging did not increase the accuracy of lymph node staging for our patients with esophageal carcinoma, which had already been defined through CT. Therefore, no new consequences resulted for the surgical procedure. Due to the high costs involved with PET investigation, lymph node staging with it is momentarily indicated mainly for clinical studies and when CT does not offer unequivocal results. Increased sensitivity of the already advantageous whole-body FDG-PET imaging by means of tumor-affinitive radiopharmaceuticals and optimized apparatus resolution could lead to new indications for this staging procedure.