Mediastinal lymph node staging with FDG-PET scan in patients with potentially operable non-small cell lung cancer: a prospective analysis of 50 cases. Leuven Lung Cancer Group

Utility of PET-CT in non-small cell lung cancer clinical stage IB-IIA according to AJCC 8th edition staging system: an alternative to invasive mediastinal staging?

Objective

Mediastinal nodal staging in lung cancer is essential to determine treatment strategy and prognosis. There are controversies as to whether a mediastinal negative result in PET-CT may spare the invasive staging of the mediastinum. The main endpoint is to evaluate the negative predictive value (NPV) of PET-CT in non-small cell lung cancer (NSCLC) clinical stage IB-IIA without clinical nodal involvement. The secondary endpoint is to evaluate the prevalence of mediastinal and hilar nodal affection in this population.

Methods

We performed an observational descriptive study from January 2010 to January 2020, including 76 patients with clinical stage IB-IIA, who underwent pulmonary resection with systematic nodal sampling (pre-determined lymph node stations based on tumour location) for primary NSCLC. Clinically, nodal involvement was defined as any lymph node greater than 1 cm in the short axis on a CT or with metabolic uptake greater than 2.5 SUV on PET-CT. The prevalence of nodal metastases was recorded.

Results

Fifty six patients had clinical stage IB and 20 had clinical stage IIA. Mean tumour size was 3.74 ± 0.5 cm. Lobectomy was the resection procedure most frequently performed. Of the 76 patients with clinical N0 by PET-CT who underwent surgical resection, 10 (13.1%) were upstaged to pN1 and none were upstaged to pN2. NPV of PET-CT for overall nodal metastasis was 87% (95% CI: 0.79-0.94). NPV of PET-CT for N2 metastasis was 100%.

Conclusion

PET-CT might be an alternative to invasive mediastinal staging in patients with NSCLC clinical stage IB-IIA who are surgical candidates. Further prospective multi-institutional studies are necessary to verify the external validity of our study.

Combining Independent Studies of Diagnostic Fluorodeoxyglucose Positron-Emission Tomography and Computed Tomography in Mediastinal Lymph Node Staging for Non-Small Cell Lung Cancer

Aims and background

A meta-analysis of diagnostic test performance was conducted to compare the results of relevant studies reporting diagnostic accuracy values for mediastinal staging in patients with non-small cell lung cancer (NSCLC). This paper deals with the two most accurate imaging techniques currently in use: positron emission tomography (PET) with FDG and computed tomography (CT). A statistical pooling method was used to perform a quantitative meta-analysis aimed at demonstrating the potential advantage of one of these two methods.

Methods

Studies in all languages published between 1998 and 2005 that examined the use of FDG-PET and CT for mediastinal staging in NSCLC patients, enrolled at least 18 participants, and provided enough data to allow calculation of sensitivity and specificity rates were considered eligible for the quantitative meta-analysis. Statistical methods to pool the overall estimates of sensitivity and specificity and to compare the discriminant power of PET and CT were discussed and used.

Results

Of the 13 studies included in the analysis, 12 reported greater accuracy of FDG-PET than CT in detecting mediastinal lymph node metastases. The sensitivity of FDG-PET ranged from 50% to 100%. The estimate of the overall sensitivity was 0.83% with 95% CI (0.749–0.913). Specificity ranged from 79% to 100%, with an overall estimated specificity of 0.87% with 95% CI (0.80–0.95). For CT, the sensitivity and specificity ranged from 50% to 97% and 58% to 94%, respectively; the overall estimate was 0.68% with 95% CI (0.582–0.788) and 0.76% with 95% CI (0.668–0.859). The summary receiver operating characteristic (SROC) approach was used to assess the superior diagnostic accuracy of one of the two methods. The areas under the two SROC curves were AUCPET = 0.909 vs AUCCT = 0.794.

Conclusions

Numerical and visual results of the meta-analysis of recent relevant reports agreed that FDG-PET is more accurate than CT in identifying mediastinal lymph node metastases in non-small cell lung cancer.

Pulmonologist's Road Map to Mediastinal Lymph Node Imaging

Mediastinal lymph node station maps are intended to facilitate nodal staging in patients with non-small cell lung cancer. These maps have been revised over time and the International Association for Study of Lung Cancer (IASLC) map is the latest rendition. This article illustrates the imaging appearance of each of the IASLC map mediastinal lymph node stations, overviews some of the mediastinal lymph node sampling techniques, and discusses common pitfalls of the IASLC map. It also reviews mediastinal anatomic variants and pathologic features that may simulate lymphadenopathy.

Pre- and postoperative care for stage I-III NSCLC: Which quality of care indicators are evidence-based?

Identification of evidenced-based Quality of Care (QoC) indicators for lung cancer care is essential to quality improvement. The aim of this review was to identify evidence-based quality indicators for the pre- and postoperative care of stage I-III Non Small Cell Lung Cancer (NSCLC) provided by the lung physician. To obtain these indicators, a search in PubMed, Embase and the Cochrane library database was performed. English literature published between 1980 and 2012 was included and search terms regarding 'lung neoplasms', 'quality of care', 'pathology', 'diagnostic methods', 'preoperative and postoperative treatment' were used. The potential indicators were categorized as structure, process or outcome measures and the indicators supported by literature with high evidence level were selected. Five QoC indicators were identified. The use of the positron emission tomography-computed tomography (PET-CT) results in more accurate mediastinal staging compared to the CT scan. Endoscopic Ultrasound-Fine Needle Aspiration and Endobronchial Ultrasound-Fine Needle Aspiration are sensitive diagnostic tools for mediastinal staging and reduce futile thoracotomies. Pathological conformation of lung cancer can best be obtained by a combination of cytological and histological diagnostics used during bronchoscopy. For patients with clinical stage III NSCLC, preoperative multimodality treatment (i.e. preoperative chemoradiation) results in superior survival and increased mediastinal downstaging compared to single modality treatment (i.e. preoperative chemotherapy or radiotherapy). After surgery, the addition of chemotherapy results in a significant survival benefit for patients with pathological stage II and III NSCLC. These five QoC indicators can be used for benchmarking and ultimately quality improvement of lung cancer care.

Predicted extracapsular invasion of hilar lymph node metastasis by fusion positron emission tomography/computed tomography in patients with lung cancer

Intraoperative detection of hilar lymph node metastasis, particularly with extracapsular invasion, may affect the surgical procedure in patients with lung cancer, as the preoperative estimation of hilar lymph node metastasis is unsatisfactory. The aim of this study was to investigate whether fusion positron emission tomography/computed tomography (PET/CT) is able to predict extracapsular invasion of hilar lymph node metastasis. Between April, 2007 and April, 2013, 509 patients with primary lung cancer underwent surgical resection at our institution, among whom 28 patients exhibiting hilar lymph node metastasis (at stations 10 and 11) were enrolled in this study. A maximum lymph node standardized uptake value of >2.5 in PET scans was interpreted as positive. A total of 17 patients had positive preoperative PET/CT findings in their hilar lymph nodes, while the remaining 11 had negative findings. With regard to extracapsular nodal invasion, the PET/CT findings (P=0.0005) and the histological findings (squamous cell carcinoma, P=0.05) were found to be significant predictors in the univariate analysis. In the multivariate analysis, the PET/CT findings were the only independent predictor (P=0.0004). The requirement for extensive pulmonary resection (sleeve lobectomy, bilobectomy or pneumonectomy) was significantly more frequent in the patient group with positive compared with the group with negative PET/CT findings (76 vs. 9%, respectively, P=0.01). Therefore, the PET/CT findings in the hilar lymph nodes were useful for the prediction of extracapsular invasion and, consequently, for the estimation of possible extensive pulmonary resection.

Evidence based imaging strategies for solitary pulmonary nodule

Solitary pulmonary nodule (SPN) is defined as a rounded opacity ≤3 cm in diameter surrounded by lung parenchyma. The majority of smokers who undergo thin-section CT have SPNs, most of which are smaller than 7 mm. In the past, multiple follow-up examinations over a two-year period, including CT follow-up at 3, 6, 12, 18, and 24 months, were recommended when such nodules are detected incidentally. This policy increases radiation burden for the affected population. Nodule features such as shape, edge characteristics, cavitation, and location have not yet been found to be accurate for distinguishing benign from malignant nodules. When SPN is considered to be indeterminate in the initial exam, the risk factor of the patients should be evaluated, which includes patients' age and smoking history. The 2005 Fleischner Society guideline stated that at least 99% of all nodules 4 mm or smaller are benign; when nodule is 5-9 mm in diameter, the best strategy is surveillance. The timing of these control examinations varies according to the nodule size (4-6, or 6-8 mm) and the type of patients, specifically at low or high risk of malignancy concerned. Noncalcified nodules larger than 8 mm diameter bear a substantial risk of malignancy, additional options such as contrast material-enhanced CT, positron emission tomography (PET), percutaneous needle biopsy, and thoracoscopic resection or videoassisted thoracoscopic resection should be considered.

Appropriate use of positron emission tomography with [(18)F]fluorodeoxyglucose for staging of oncology patients

Positron emission tomography (PET) was developed in the mid-1970, and its initial applications were for heart and brain imaging research. Nowadays, this technology is aimed mainly at staging or restaging tumours as it allows the assessment of biochemical processes that are either specific or associated with tumour biology. The full appreciation of PET potentials and limitations among general practitioners and internists cannot be considered achieved and the appropriate use of PET especially when coupled to X-ray computed tomography (CT) is still suboptimal. The majority of PET studies rely on the use of fluorodeoxyglucose labelled with fluorine-18 (FDG), which is a radiopharmaceutical specific for glucose transport and metabolism. PET with FDG is amenable for studying most type of tumours, including those of the head and neck, lung, oesophagus, colo-rectal, gastrointestinal stromal tumours, pancreas, some types of lymphomas and melanoma, whereas in some tumours, including those of the reproductive system, brain, breast and bones, there is a limited role for PET and there is no substantial role for FDG-PET for the bronchoalveolar, hepatocellular, urinary system, testicular, neuroendocrine, carcinoids and adrenal tumours, differentiated thyroid cancers, and several subtypes of malignant lymphoma. Thus, the limits of FDG have stimulated the use and development of other radiopharmaceuticals. These tracers represent the opportunity for expanding the use of PET to other areas in oncology in the near future.

Additional value of FDG-PET to contrast enhanced-computed tomography (CT) for the diagnosis of mediastinal lymph node metastasis in non-small cell lung cancer: a Japanese multicenter clinical study

OBJECTIVE

This study was a controlled multicenter clinical study to verify the diagnostic effects of additional FDG-PET to contrast-enhanced CT for mediastinal lymph node metastasis in patients with operable non-small cell lung cancer (NSCLC).

METHODS

NSCLC patients with enlarged mediastinal lymph nodes (short diameter, 7-20 mm), confirmed using contrast-enhanced CT, were examined using FDG-PET to detect metastases prior to surgery. The primary endpoint was the accuracy for concomitantly used CT and FDG-PET showing the additional effects of FDG, compared with CT alone. The secondary endpoints were the clinical impact of FDG-PET on therapeutic decisions and adverse reaction from FDG administration. The images were interpreted by investigators at each institution. Moreover, blinded readings were performed by an image interpretation committee independent of the institutions. The gold standard was the pathological diagnosis determined by surgery or biopsy after PET, and patients in whom a pathological diagnosis was not obtained were excluded from the analysis.

RESULTS

Among 99 subjects, the results for 81 subjects eligible for analysis showed that the accuracy improved from 69.1% (56/81) for CT alone to 75.3% (61/81) for CT + PET (p = 0.404). These findings contributed to treatment decisions in 63.0% (51/81) of the cases, mainly with regard to the selection of the operative procedure. The results of the image interpretation committee showed that the accuracy improved from 64.2% (52/81) (95% CI 52.8-74.6) for CT to 75.3% (61/81) (95% CI 64.5-84.2) for CT + PET. The accuracy for 106 mediastinal lymph nodes improved significantly from 62.3% (66/106) (95% CI 52.3-71.5) for CT to 79.2% (84/106) (95% CI 70.3-86.5) for CT + PET (p < 0.05). We found that no serious adverse drug reactions appeared in any of the 99 patients who received FDG, except for transient mild outliers in the laboratory data for two patients.

CONCLUSIONS

The addition of FDG-PET to contrast-enhanced CT imaging for the staging of NSCLC improved the diagnostic accuracy for mediastinal lymph node metastasis. FDG-PET improved the precision of the staging of NSCLC and contributed to the surgical decisions.

Diagnostic value of EBUS-TBNA for lung cancer with non-enlarged lymph nodes: a study in a tuberculosis-endemic country

BACKGROUND

In tuberculosis (TB)-endemic areas, contrast-enhanced computed tomography (CT) and positron emission tomography (PET) findings of lung cancer patients with non-enlarged lymph nodes are frequently discrepant. Endobronchial ultrasound-guided transbronchial aspiration (EBUS-TBNA) enables real-time nodal sampling, and thereby improves nodal diagnosis accuracy. This study aimed to compare the accuracy of nodal diagnosis by using EBUS-TBNA, and PET.

METHODS

We studied 43 lung cancer patients with CT-defined non-enlarged mediastinal and hilar lymph nodes and examined 78 lymph nodes using EBUS-TBNA.

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of EBUS-TBNA were 80.6%, 100%, 100%, and 85.7%, respectively. PET had low specificity (18.9%) and a low positive predictive value (44.4%). The diagnostic accuracy of EBUS-TBNA was higher than that of PET (91% vs. 47.4%; p<0.001). Compared to CT-based nodal assessment, PET yielded a positive diagnostic impact in 36.9% nodes, a negative diagnostic impact in 46.2% nodes, and no diagnostic impact in 16.9% nodes. Patients with lymph nodes showing negative PET diagnostic impact had a high incidence of previous pulmonary TB. Multivariate analysis indicated that detection of hilar nodes on PET was an independent predictor of negative diagnostic impact of PET.

CONCLUSION

In a TB-endemic area with a condition of CT-defined non-enlarged lymph node, the negative diagnostic impact of PET limits its clinical usefulness for nodal staging; therefore, EBUS-TBNA, which facilitates direct diagnosis, is preferred.

Preoperative nodal staging of non-small cell lung cancer using 99mTc-sestamibi spect/ct imaging

OBJECTIVES

The proper nodal staging of non-small cell lung cancer is important for choosing the best treatment modality. Although computed tomography remains the first-line imaging test for the primary staging of lung cancer, its limitations for mediastinum nodal staging are well known. The aim of this study is to evaluate the accuracy of hybrid single-photon emission computed tomography and computed tomography using 99mTc-sestamibi in the nodal staging of patients with non-small cell lung cancer and to identify potential candidates for surgical treatment.

METHODS

Prospective data were collected for 41 patients from December 2006 to February 2009. The patients underwent chest computed tomography and single-photon emission computed tomography/computed tomography examinations with 99mTc-sestamibi within a 30-day time period before surgery. Single-photon emission computed tomography/computed tomography was considered positive when there was focal uptake of sestamibi in the mediastinum, and computed tomography scan when there was lymph nodes larger than 10 mm in short axis. The results of single-photon emission computed tomography and computed tomography were correlated with pathology findings after surgery.

RESULTS

Single-photon emission computed tomography/computed tomography correctly identified six out of 19 cases involving hilar lymph nodes and one out of seven cases involving nodal metastases in the mediastinum. The sensitivity, specificity, positive predictive value, and negative predictive value for 99mTc-sestamibi single-photon emission computed tomography/computed tomography in the hilum assessment were 31.6%, 95.5%, 85.7%, and 61.8%, respectively. The same values for the mediastinum were 14.3%, 97.1%, 50%, and 84.6%, respectively. For the hilar and mediastinal lymph nodes, chest tomography showed sensitivity values of 47.4% and 57.1%, specificity values of 95.5% and 91.2%, positive predictive values of 90% and 57.1% and negative predictive values of 67.7% and 91.2%, respectively.

CONCLUSION

Single-photon emission computed tomography/computed tomography with 99mTc-sestamibi showed very low sensitivity and accuracy for the nodal staging of patients with non-small cell lung cancer, despite its high level of specificity. In addition, the performance of single-photon emission computed tomography/computed tomography added no relevant information compared to computed tomography that would justify its use in the routine preoperative staging of non-small cell lung carcinoma.

Carinal surgery: experience of a single center and review of the current literature

Background

To report our experience for the treatment of lung tumors of the right main bronchus (RMB) invading the carina.

Methods

From February 2000 till January 2007 we have identified 8 cases (1.09%) requiring carinal surgery.

Plan of action: Close cooperation with anaesthetics, long flexible ET tube, Right posterolateral thoracotomy, no irrevocable steps until resection guaranteed, mobilization of trachea and main bronchus, division of the trachea & Left main bronchus. Intubate across surgical field. Tailoring for airway size discrepancies, appropriately. Construction of the tracheobronchial anastomosis around the ventilatory tube. Skillfull reintubation, over a long boogie.

Results

Mortality: 12.5% due to ARDS (one patient)

Morbidity: anastomotic stenosis requiring stent (one patient). Follow-up 52 ± 11 months.

Recurrences: 2 patients (both with pathological N2 disease on histology).

Conclusions

Success of carinal surgery depends on careful patient selection, team approach and attention to detail. Patients with N2 disease carry the worst prognosis.

High correlations between primary tumours and loco-regional metastatic lymph nodes in non-small-cell lung cancer with respect to glucose transporter type 1-mediated 2-deoxy-2-F18-fluoro-D-glucose uptake

The purpose of the study was to investigate whether glucose transporter type 1 (Glut-1) mediated 2-deoxy-2-F18-fluoro-D-glucose (FDG) uptake of primary tumour is related to the likelihood of malignancy involvement in loco-regional lymph nodes (LNs) in 126 non-small-cell lung cancer (NSCLC) patients (M:F=103:23, age=65+/-9.7 years). Maximum standardised uptake values (maxSUV) and Glut-1 expression levels (determined by PET and immunostaining, respectively) of primary tumours and PET positive loco-regional LNs were compared. Significant correlations were found between malignant LNs and primary tumours with respect to maxSUV (r=0.6451, p<0.0001), %Glut-1 expression (r=0.8341, p<0.0001) and Glut-1 staining intensity (rho=0.827, p<0.0001). The area-under-curve value for LN differentiation using lymph node maxSUV was significantly higher in patients with a primary tumour maxSUV of >6 (AUC=0.775, p=0.0001). High correlations between the primary tumours and metastatic LNs in NSCLC with respect to the Glut-1 mediated FDG uptake may be useful for mediastinal LN discrimination by FDG-PET.

Staging of Lung Cancer

Imaging techniques play a vital role in the diagnosis, staging, and follow-up of patients who have lung cancer. For this purpose, PET has become an important adjunct to conventional imaging techniques such as chest radiography, CT, ultrasonography, and MR imaging. The ability of PET to differentiate the metabolic properties of tissues allows more accurate assessment of undetermined lung lesions, mediastinal lymph nodes, or extrathoracic abnormalities, tumor response after induction treatment, and detection of disease recurrence.

Comparison of endobronchial ultrasound, positron emission tomography, and CT for lymph node staging of lung cancer

STUDY OBJECTIVES

To perform a prospective comparison of direct real-time endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA), positron emission tomography (PET), and thoracic CT for detection of mediastinal and hilar lymph node metastasis in patients with lung cancer considered for surgical resection.

DESIGN

Prospective patient enrollment.

SETTING

University teaching hospital.

PATIENTS

One hundred two potentially operable patients with proven (n = 96) or radiologically suspected (n = 6) lung cancer were included in the study.

INTERVENTIONS

CT, PET, and EBUS-TBNA were performed prior to surgery for the evaluation of mediastinal and hilar lymph node metastasis. The convex probe EBUS, which is integrated with a convex scanning probe on its tip, was used for EBUS-TBNA. Surgical histology was used as the "gold standard" to confirm lymph node metastasis unless patients were found inoperable for N3 or extensive N2 disease proven by EBUS-TBNA.

MAIN RESULTS

EBUS-TBNA was successfully performed in all 102 patients (mean age, 67.8 years) from 147 mediastinal and 53 hilar lymph nodes. EBUS-TBNA proved malignancy in 37 lymph node stations in 24 patients. CT identified 92 positive lymph nodes, and PET identified 89 positive lymph nodes (4 supraclavicular, 63 mediastinal, 22 hilar). The sensitivities of CT, PET, and EBUS-TBNA for the correct diagnosis of mediastinal and hilar lymph node staging were 76.9%, 80.0%, and 92.3%, respectively; specificities were 55.3%, 70.1%, and 100%, and diagnostic accuracies were 60.8%, 72.5%, and 98.0%. EBUS-TBNA was uneventful, and there were no complications.

CONCLUSION

Compared to CT and PET, EBUS-TBNA has a high sensitivity as well as specificity for mediastinal and hilar lymph node staging in patients with lung cancer. EBUS-TBNA should be considered for evaluation of the mediastinum early in the staging process of lung cancer.

Prospective comparative study of integrated positron emission tomography-computed tomography scan compared with remediastinoscopy in the assessment of residual mediastinal lymph node disease after induction chemotherapy for mediastinoscopy-proven stage IIIA-N2 Non-small-cell lung cancer: a Leuven Lung Cancer Group Study

PURPOSE

Mediastinal restaging after induction therapy for non-small-cell lung cancer remains a difficult and controversial issue. The goal of this prospective study was to compare the performance of integrated positron emission tomography (PET)--computed tomography (CT) and remediastinoscopy in the evaluation of mediastinal lymph node metastasis after induction chemotherapy.

PATIENTS AND METHODS

Thirty consecutive stage IIIA-N2 non-small-cell lung cancer patients surgically treated at our institution were entered onto this prospective study. N2 disease was proven by cervical mediastinoscopy, at which a mean number of 3.8 lymph node levels were biopsied. After completion of induction chemotherapy, the mediastinum was reassessed by integrated PET-CT and remediastinoscopy. All patients underwent thoracotomy with attempted complete resection and systematic nodal dissection.

RESULTS

PET-CT showed no evidence of nodal disease (N0) in 13 patients, Hilar nodal disease (N1) disease in three patients, and residual mediastinal disease (N2) in 14 patients. Remediastinoscopy was positive in only five patients. The preinduction involved lymph node level could be accurately re-evaluated in 18 patients. This was not the case in the other 12 because of extensive fibrosis and adhesions. In 17 patients, persistent N2 disease was found at thoracotomy. The sensitivity, specificity, and accuracy of PET-CT were 77%, 92%, and 83%, respectively. These parameters for remediastinoscopy were 29%, 100%, and 60%, respectively. Sensitivity (P < .0001) and accuracy (P = .012) were significantly better for PET-CT.

CONCLUSION

After a thorough staging mediastinoscopy, postinduction remediastinoscopy had a disappointing sensitivity because of adhesions and fibrosis. Integrated PET-CT yielded a better result than that obtained in previous studies with side-by-side PET and CT images.

Quantitative analysis and effect of attenuation correction on lymph node staging of non-small cell lung cancer on SPECT and CT

OBJECTIVE

The purpose of our study was to assess quantitative indexes and the effect of attenuation correction on the evaluation of lymph node metastasis in the staging of non-small cell lung cancer (NSCLC) using fused thallium-201 SPECT/CT images.

MATERIALS AND METHODS

We evaluated 156 lymph nodes (66 metastatic, 90 nonmetastatic) from 29 patients with NSCLC. Using our combined SPECT/CT system, all patients underwent 201Tl SPECT and CT examinations immediately (early images) and 3 hr after (delayed images) the injection of 201Tl. SPECT images were reconstructed with and without attenuation correction. For the quantitative evaluation of lymph node metastasis, we calculated the early ratio, the delayed ratio, and the washout ratio for SPECT images and the short-axis diameter for CT images. Receiver operating characteristic (ROC) analysis was performed in each index for the differentiation between metastatic and nonmetastatic lymph nodes. Visual analysis was also performed by two experienced radiologists.

RESULTS

The area under the ROC curve (A(z)) showed that early ratio and delayed ratio were superior to short-axis diameter for the assessment of lymph node metastasis. In addition, early and delayed ratios on attenuation-corrected images were superior to those ratios on images without attenuation correction. However, the A(z) value for washout ratio was smaller than that for short-axis diameter. Early ratio on attenuation-corrected images was the most useful index (A(z) = 0.94). The sensitivity, specificity, and accuracy for early ratio on attenuation-corrected images were 78.8%, 94.4%, and 87.8% for the diagnosis of lymph node metastasis and 84.6%, 100%, and 93.1% for clinical staging (N0-N1 vs N2-N3), respectively. Fused images showed significantly higher diagnostic accuracy than CT images on visual analysis.

CONCLUSION

Quantitative assessment using fused SPECT/CT images is useful for the diagnosis of lymph node metastasis in patients with NSCLC.

Traditional versus up-front [18F] fluorodeoxyglucose-positron emission tomography staging of non-small-cell lung cancer: a Dutch cooperative randomized study

PURPOSE

We investigated whether application of positron emission tomography (PET) immediately after first presentation might simplify staging while maintaining accuracy, as compared with traditional strategy in routine clinical setting.

METHODS

At first presentation, patients with a provisional diagnosis of lung cancer without overt dissemination were randomly assigned to traditional work-up (TWU) according to international guidelines or early PET followed by histologic/cytologic verification of lesions, or imaging and follow-up. Patients with [18F] fluorodeoxyglucose (18FDG) -avid, noncentral tumors without suspicion of mediastinal or distant metastases on PET proceeded directly to thoracotomy. Follow-up in presumed benign lesions was at least 12 months. In patients treated with surgery or neoadjuvant therapy, the quality of staging was measured by comparing the clinical stage to the final stage (combination of peroperative staging and 6 months of follow-up). To investigate test substitution, we analyzed the number of (non)invasive tests to achieve clinical TNM staging, and its associated costs.

RESULTS

Between 1999 and 2001, 465 patients (233 TWU, 232 PET) were enrolled at 22 hospitals. The mean (standard deviation) number of procedures to finalize staging was equal in the TWU arm and the PET arm: 7.9 (2.0) v 7.9 (1.9), P = .90, respectively. Mediastinoscopies occurred significantly less often in the PET arm. Agreement between clinical and final stage was good in both arms (kappa = .85 v .78; P = .07). Costs did not differ significantly.

CONCLUSION

Up-front 18FDG-PET in patients with (suspected) lung cancer does not reduce the overall number of diagnostic test, but it maintains quality of TNM staging with the use of less invasive surgery.

Meta-analysis of positron emission tomographic and computed tomographic imaging in detecting mediastinal lymph node metastases in nonsmall cell lung cancer

A systematic review was undertaken to select studies that compared the accuracy of 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography with computed tomographic imaging in detecting mediastinal lymph node metastases in patients with nonsmall cell lung cancer. Two authors selected relevant articles according to predefined criteria. With a meta-analytic method, summary receiver operating characteristic curves were constructed. The point on the receiver operating characteristic curve with equal sensitivity and specificity for 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography was Q* = 0.90 (95% confidence interval [CI], 0.86 to 0.95). For computed tomography it was 0.70 (95% CI, 0.65 to 0.75). The difference was highly significant (p < 0.0001). We conclude that 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography is more accurate than computed tomography in detecting mediastinal lymph node metastases.

Seeking a home for a PET, part 3: Emerging applications of positron emission tomography imaging in the management of patients with lung cancer

Positron emission tomography (PET) imaging is an important tool to refine the diagnosis and staging approach in patients with a possible lung cancer. In addition, other applications of PET imaging are being explored. Data consistently show that the intensity of uptake on a PET scan correlates with the biological aggressiveness of a tumor. PET imaging for restaging after induction therapy does not appear to be accurate enough to guide management. The results of PET imaging late after completion of treatment are highly predictive of future survival, and changes in PET images after only one cycle of chemotherapy are predictive of how a patient will respond to that planned treatment. PET imaging may allow radiotherapy treatment fields to be planned with greater accuracy, although data on how this affects patient outcomes are not yet available. Further technologic improvements in PET scanners are likely to bring further benefits to the management of patients with lung cancer in the future.

Endoscopic Ultrasound in Non–Small Cell Lung Cancer and Negative Mediastinum on Computed Tomography

Despite technical advances in staging non-small cell lung cancer (NSCLC), accurate staging remains a challenge. Endoscopic ultrasound is useful in staging NSCLC when lymphadenopathy is present on a computed tomography (CT), but its role in the absence of lymphadenopathy on CT has not been well defined. Therefore, we sought to determine the clinical impact of endoscopic ultrasound (EUS) in staging NSCLC in absence of mediastinal lymphadenopathy on CT. Seventy-six patients with NSCLC with absence of mediastinal lymphadenopathy on CT were enrolled and followed prospectively. EUS-guided fine-needle aspiration was performed on sites that were suspicious for metastases. Surgical pathology after thoracotomy was used as the reference standard for assessing accuracy. Sixty-two (86%) patients underwent surgery, and 10 (13%) did not. EUS precluded surgery in 9 patients (12%) and influenced management in 18 (25%) of all patients in this study. EUS detected malignant mediastinal lymphadenopathy more frequently in patients with lower lobe and hilar cancers combined compared with upper lobe cancers (p = 0.004). EUS played a significant role in identifying patients with unresectable (N3) NSCLC when adenopathy was not present on CT imaging and appears to be more sensitive in detecting lymph node metastases in lower lobe and hilar NSCLC compared with upper lobe NSCLC.

The Role of PET Scan in Diagnosis, Staging, and Management of Non‐Small Cell Lung Cancer

Positron emission tomography (PET) is now an important cancer imaging tool, both for diagnosis and staging, as well as offering prognostic information based on response. This report attempts to comprehensively review the value of PET in the locoregional and distant staging of non-small cell lung cancer (NSCLC), illustrate the potential effects on patient management, and give a short overview of newer applications. PET sets the gold standard in the evaluation of an indeterminate solitary pulmonary nodule or mass, where PET has proven to be significantly more accurate than computed tomography (CT) in the distinction between benign and malignant lesions. In the evaluation of metastatic spread to locoregional lymph nodes, PET is significantly more accurate than CT, so that invasive surgical staging may be omitted in many patients with negative mediastinal PET images. In patients with positive mediastinal PET images, invasive surgical staging remains mandatory because of the possibility of false-positive findings due to inflammatory nodes or granulomatous disorders. In the search for metastatic spread, PET is a useful adjunct to conventional imaging. This may be due to the finding of unexpected metastatic lesions or due to exclusion of malignancy in lesions that are equivocal on standard imaging. However, at this time, PET does not replace conventional imaging. Large-scale randomized studies are currently examining whether PET staging will actually improve the appearance of lung cancer outcome.

False-positive and true-negative hilar and mediastinal lymph nodes on FDG-PET--radiological-pathological correlation

OBJECTIVE

To compare histological findings of FDG-PET false-positive and true-negative hilar and mediastinal lymph nodes.

METHODS

Sixty-seven lymphnode areas in 11 patients who were diagnosed to have N3 lymph nodes by FDG-PET and underwent surgery were histologically examined, and the histopathological findings in false-positive and true-negative lymph nodes were compared. Lymph nodes with higher accumulation of FDG than the surrounding mediastinum level were judged as positive. On histological sections, proportions of macrophages and lymphocytes, amount of coal dust deposit, presence of silicotic nodules, long- and short-axes of the largest node, and volume of macrophages and lymphocytes were evaluated. Correlations between the above-mentioned factors and FDG accumulation were evaluated.

RESULTS

FDG uptake was not correlated with the proportion of macrophages and lymphocytes, coal dust amounts, or the presence of silicotic nodules. The long- and short-axes of the largest node in the false-positive areas were significantly longer than those in the true-negative areas (p = 0.01, and 0.001, respectively). Volumes of lymph nodes (mean +/- SD: 150 +/- 190 mm3) and macrophages (78 +/- 71 mm3) in false-positive areas were markedly larger than those in true-negative areas (68 +/- 87 mm3, p = 0.0009 and 34 +/- 54 mm3, p = 0.0001, respectively). The volume of lymphocytes was also larger in false-positive areas but less markedly.

CONCLUSION

Our study suggested that false-positive results of FDG-PET in hilar and mediastinal lymph nodes were closely related to the size of lymph node and the volume of macrophages.

The spectrum of treatment and future diagnosis of early non-small cell lung carcinoma

PURPOSE

Review the surgical treatment of 56 patients at a single institution of early stage non-small cell lung carcinoma (NSCLC). Briefly review the literature to report the current indications for limited pulmonary resection. Discuss newer methods of assessing early stage NSCLC.

METHODS

We reviewed 56 lobectomies performed at the Biloxi Veterans Administration Medical Center from January 1992 to December 1997 for NSCLC to report the incidence of N1 positive lymph nodes and survival data. Additionally, a search of PubMed, Ovid, and MDConsult.com, using search parameters of non-small cell lung carcinoma, limited pulmonary resection, lobectomy, and comorbidity, were used to determine indications for treating non-small cell lung carcinoma.

RESULTS

N1 positive lymph nodes occurred in 11 out of 56 patients; 4 were identified preoperatively. In this sample, 21 patients were Stage IA, 21 Stage IB, 6 Stage IIA, and 8 Stage IIB, and their 4-year median survival was as follows: (IA) greater than 44.80 months, (IB) greater than 48.0 months, (IIA) greater than 25.28 months, and (IIB) = 11.18 months. Four-year survival rates by stage were IA= 10/21 (47.62%), IB= 14/21 (66.67%), IIA= 2/6 (33.33%), and IIB= 0/8 (0.0%).

CONCLUSIONS

The 4-year survival data we reviewed were less favorable than is reported by others. Patient medical comorbidity, patient age, and sample size are thought to account for this difference. According to our literature review, reasons for limited pulmonary resection include poor physical performance, marginal lung reserve, synchronous bilateral tumors, and superior sulcus tumors (T3) in which the tumor primarily invades the chest wall. Heavier consideration of these indications might have improved the outcomes seen in this population.