The role of computed tomographic scanning in diagnosing mediastinal node involvement in non-small cell lung cancer

Predictive value of radiomic features extracted from primary lung adenocarcinoma in forecasting thoracic lymph node metastasis: a systematic review and meta-analysis

BACKGROUND

The application of radiomics in thoracic lymph node metastasis (LNM) of lung adenocarcinoma is increasing, but diagnostic performance of radiomics from primary tumor to predict LNM has not been systematically reviewed. Therefore, this study sought to provide a general overview regarding the methodological quality and diagnostic performance of using radiomic approaches to predict the likelihood of LNM in lung adenocarcinoma.

METHODS

Studies were gathered from literature databases such as PubMed, Embase, the Web of Science Core Collection, and the Cochrane library. The Radiomic Quality Score (RQS) and the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) were both used to assess the quality of each study. The pooled sensitivity, specificity, and area under the curve (AUC) of the best radiomics models in the training and validation cohorts were calculated. Subgroup and meta-regression analyses were also conducted.

RESULTS

Seventeen studies with 159 to 1202 patients each were enrolled between the years of 2018 to 2022, of which ten studies had sufficient data for the quantitative evaluation. The percentage of RQS was between 11.1% and 44.4% and most of the studies were considered to have a low risk of bias and few applicability concerns in QUADAS-2. Pyradiomics and logistic regression analysis were the most commonly used software and methods for radiomics feature extraction and selection, respectively. In addition, the best prediction models in seventeen studies were mainly based on radiomics features combined with non-radiomics features (semantic features and/or clinical features). The pooled sensitivity, specificity, and AUC of the training cohorts were 0.84 (95% confidence interval (CI) [0.73-0.91]), 0.88 (95% CI [0.81-0.93]), and 0.93(95% CI [0.90-0.95]), respectively. For the validation cohorts, the pooled sensitivity, specificity, and AUC were 0.89 (95% CI [0.82-0.94]), 0.86 (95% CI [0.74-0.93]) and 0.94 (95% CI [0.91-0.96]), respectively.

CONCLUSIONS

Radiomic features based on the primary tumor have the potential to predict preoperative LNM of lung adenocarcinoma. However, radiomics workflow needs to be standardized to better promote the applicability of radiomics.

TRIAL REGISTRATION

CRD42022375712.

Prognostic impact of artificial intelligence-based volumetric quantification of the solid part of the tumor in clinical stage 0-I adenocarcinoma

INTRODUCTION

The size of the solid part of a tumor, as measured using thin-section computed tomography, can help predict disease prognosis in patients with early-stage lung cancer. Although three-dimensional volumetric analysis may be more useful than two-dimensional evaluation, measuring the solid part of some lesions is difficult using this methods. We developed an artificial intelligence-based analysis software that can distinguish the solid and non-solid parts (ground-grass opacity). This software calculates the solid part volume in a totally automated and reproducible manner. The predictive performance of the artificial intelligence software was evaluated in terms of survival or recurrence-free survival.

METHODS

We analyzed the high-resolution computed tomography images of the primary lesion in 772 consecutive patients with clinical stage 0-I adenocarcinoma. We performed automated measurement of the solid part volume using an artificial intelligence-based algorithm in collaboration with FUJIFILM Corporation. The solid part size, the solid part volume based on traditional three-dimensional volumetric analysis, and the solid part volume based on artificial intelligence were compared.

RESULTS

Higher areas under the curve related to the solid part volume were provided by the artificial intelligence-based method (0.752) than by the solid part size (0.722) and traditional three-dimensional volumetric analysis-based method (0.723). Multivariate analysis demonstrated that the solid part volume based on artificial intelligence was independently correlated with overall survival (P = 0.019) and recurrence-free survival (P < 0.001).

CONCLUSION

The solid part volume measured by artificial intelligence was superior to conventional methods in predicting the prognosis of clinical stage 0-I adenocarcinoma.

Latest Clinical Evidence and Operative Strategy for Small-Sized Lung Cancers

Many thoracic surgeons revealed that consolidation tumor ratio or solid component size on thin-section computed tomography has been considered more prognostic than maximum tumor size in non-small cell lung cancer (NCSLC). According to the results, the 8th TNM classification drastically changed the staging system, i.e., clinical T category was determined based on the invasive or solid component size excluding a ground-glass opacity (GGO). However, several debates are arising over the application of radiological solid size for the clinical T staging. Meanwhile, recent several institutional reports have noticed a significantly simple fact that the presence of a GGO denotes an influence on the favorable prognosis of NSCLC. More important, radiologic pure-solid lung cancers without a GGO exhibit more malignant behaviors with regard to both the clinical and pathological aspects, and show several histologic types that have a poorer prognosis than radiologic part-solid lung cancer. In contrast, favorable prognostic impact of the presence of a GGO component was demonstrated, which was irrespective of the solid component size in cases in which the tumor showed a GGO component. Recently, this concept has been gradually noticed on a nationwide level. Obvious distinctions regarding the several baseline characteristics between the tumor with/without GGO component is a fundamental biological feature of early-stage lung cancer, which would result in a big difference in prognosis, modes of recurrence, overall behavior, and appropriate operative strategies. As a future perspective, the presence or absence of a GGO should be considered as an important parameter in the next clinical T classification.

The utility of three-dimensional computed tomography for prediction of tumor invasiveness in clinical stage IA lung adenocarcinoma

Background

It is critical to have an accurate measurement of solid tumor size in order to predict the invasiveness of small lung adenocarcinomas. Some lesions cannot be measured accurately via High-resolution computed tomography (HRCT) due to their irregular shape and unclear borders. For this reason, we evaluated the relative efficacy of three-dimensional (3D) CT for predicting invasive adenocarcinoma.

Methods

We evaluated 195 patients with clinical stage IA adenocarcinomas, including 109 with lesions documented as invasive that were surgically resected at our institute during 2017. All lesions were categorized as either (I) lesions that were difficult to evaluate (i.e., hazy lesions; HL) or (II) more typical lesions (TL). The relationships between solid tumor size as determined by HRCT, solid tumor volume as determined by 3D CT and pathologic diagnosis were evaluated.

Results

Fifty-seven patients (29%) were diagnosed with HL. We set the cut-off value for the solid volume at 225 mm³ as predictive for invasive adenocarcinoma. When evaluating all 195 patients as a group, the accuracy, sensitivity, and specificity based on the solid tumor volume were similar to those based on the solid tumor size. When we limit our analysis to the HL group, the specificity based on solid tumor volume (65.5%) was higher than that based on solid tumor size (44.8%) with a difference that approached statistical significance (P=0.070).

Conclusions

3D CT was equivalent to HRCT for predicting invasive adenocarcinoma and may be particularly useful for diagnosing lesions that are difficult to evaluate on HRCT.

Prognostic impact of a ground-glass opacity component in clinical stage IA non-small cell lung cancer

OBJECTIVE

We performed a validation study to confirm the prognostic importance of the presence of a ground-glass opacity component based on data of the Japan Clinical Oncology Group study, JCOG0201, which was a prospective observational study to predict the pathological noninvasiveness of clinical stage IA lung cancer in Japan.

METHODS

Among the 811 patients registered in JCOG0201, 671 were confirmed eligible by study monitoring and a central review of computed tomography. Registered c-stage IA lung cancer was less than 30 mm in maximum tumor size, which was classified into a with ground-glass opacity group (pure ground-glass opacity and part-solid tumor) or solid group based on the status of a ground-glass opacity component. T staging was reassigned in accordance with the 8th edition of the TNM staging system. To validate the prognostic impact, overall survival was estimated.

RESULTS

Of the cases, 432 (64%) were in the with ground-glass opacity group and 239 (36%) were in the solid group with a median follow-up time of 10.1 years. The 5-year overall survival was significantly different between the with ground-glass opacity group and solid group (95.1% vs 81.1%). The 5-year overall survival was excellent regardless of the solid component size in the with ground-glass opacity group (c-T1a or less: 97.2%, c-T1b: 93.4%, c-T1c: 91.7%). In contrast, prognostic impact of the tumor size was definitive in the solid group (c-T1a: 87.5%, c-T1b: 85.9%, c-T1c: 73.7%).

CONCLUSIONS

Favorable prognostic impact of the presence of a ground-glass opacity component was demonstrated in JCOG0201. The presence or absence of a ground-glass opacity should be considered as an important parameter in the next clinical T classification.

Mediastinal lymph node staging for lung cancer

Mediastinal lymph node staging is crucial in deciding the treatment strategy for lung carcinoma. The diagnosis rate of computed tomography is not high; however, it is a standard examination. Although the contrast computed tomography is necessary for an accurate diagnosis, images from the positron emission tomography are excellent, and these two technologies are independent and complementary. Positron emission tomography has a disadvantage of false positives and false negatives, but it should also be used in cases where lymph node diameters are 1 cm or more. However, image-based diagnostic methods are not an alternative to histological examination. The results of a transbronchial needle biopsy are extremely dependent on the inspection method, the diagnostic ability of the physician, and the staging of the case. The transesophageal ultrasound endoscope is useful for reaching parts inaccessible by a mediastinoscope. Although its employment requires technical training, it is becoming popular as a minimally invasive method of obtaining cell and the tissue samples. A thoracoscopic biopsy is considered as a last resort for mediastinal lymph node diagnosis. Carefully-chosen invasive procedures are necessary to diagnose swollen lymph nodes. Although mediastinoscopy is still considered as the gold standard, most procedures will be replaced by a comparatively minimally invasive method in the future.

Improved detection of metastatic lymph nodes in oesophageal squamous cell carcinoma by combined interpretation of fluorine-18-fluorodeoxyglucose positron-emission tomography/computed tomography

Background

We sought to evaluate the diagnostic performance of fluorine-18-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the detection of metastatic lymph nodes by combined interpretation of PET/CT images in patients with oesophageal squamous cell carcinoma.

Methods

Two hundred three patients with oesophageal squamous cell carcinoma underwent ¹⁸F-FDG PET/CT before oesophagectomy and lymph node dissection. Maximum standardized uptake value (SUV_max), mean Hounsfield unit (HU), short axis diameter (size), and visual CT attenuation (high, iso-, low) were evaluated on noncontrast CT and PET images following PET/CT scan. In this combined interpretation protocol, the high attenuated lymph nodes were considered benign, even if the SUV_max value was high. The diagnostic accuracy of each method was compared using the postoperative histologic result as a reference standard.

Results

A total of 1099 nodal stations were dissected and 949 nodal stations were proven to demonstrate metastasis. SUV_max and size of the malignant lymph nodes were higher than those of the benign nodes, and visual CT attenuation was significantly different among the two groups (P < 0.001). Using cutoff values of 2.6 for SUV_max and 10.2 mm for size, the combined interpretation of an SUV_max of more than 2.6 with iso- or low CT attenuation [area under the curve (AUC): 0.846, 95% confidence interval (CI): 0.824–0.867] showed significantly better diagnostic performance for detecting malignant lymph nodes than SUV_max only (AUC: 0.791, 95% CI: 0.766–0.815) and size (AUC: 0.693, 95% CI: 0.665–0.720) methods (P < 0.001) in a receiver operating characteristic curve analysis.

Conclusions

The diagnostic accuracy of PET/CT for nodal metastasis in oesophageal squamous cell carcinoma was improved by the combined interpretation of ¹⁸F-FDG uptake and visual CT attenuation pattern.

New revisions and current issues in the eighth edition of the TNM classification for non-small cell lung cancer

In the eighth edition of the TNM classification of lung cancer, the prognostic impact of tumor size is emphasized as a descriptor of all T categories. Especially in lung cancer where tumor size is 5 cm or less, the 1-cm cutoff point significantly differentiated the survival outcome. In addition, the new staging categories were assigned, namely, Tis (adenocarcinoma in situ) and T1mi (minimally invasive adenocarcinoma). Furthermore, the measurement of a radiological solid component size excluding the ground glass opacity component or pathological invasive size without a lepidic component was proposed for deciding the cT/pT categories for lung adenocarcinoma. The N descriptors were kept the same as in the eventh edition on the whole, however, quantification of nodal disease had a prognostic impact based on the number of nodal stations involved in the eighth edition, i.e. N1a as a single N1 station, N1b as a multiple N1 station, N2a1 as a single N2 station without N1 (skip metastasis), N2a2 as a single N2 station with N1 disease, and N2b as a multiple N2 station. In the M descriptors, subclassification was performed based on the location or numbers of distantly metastatic lesions, i.e. M1a as any intrathoracic metastases, M1b as a single distant metastatic lesion in one organ, and M1c as multiple distant metastases in either a single organ or multiple organs. Survival analysis of the eighth edition of the TNM classification clearly separated the distinct groups, however, unsolved issues still remain that should be discussed and further revised for the forthcoming TNM staging system.

Prognostic value of tumor solid-part size and solid-part volume in patients with clinical stage I non-small cell lung cancer

Background

This study aimed to predict the malignant potential of clinical stage I non-small cell lung cancer (c-I NSCLC) by semiautomatic three-dimensional (3D) volumetric measurement of a tumor (3D-data) and the axial computed tomography (CT) data derived from a 3D volumetric dataset (2D-data). The predictive performance was evaluated in terms of overall survival (OS), disease-free survival (DFS), and pathological invasive factors (positive lymphatic invasion, blood vessel invasion, pleural invasion, or lymph node metastasis).

Methods

We identified 252 patients (122 male; mean age, 68 years; range, 23-84 years) with c-I NSCLC who underwent high resolution CT and reconstruction of 3D imaging, followed by complete resection between January 2012 and December 2015. In this study, 2D-data including whole tumor size (WTS) and solid-part size (SPS) and 3D-data including whole tumor volume (WTV) and solid-part volume (SPV) acquired by a 3D volume rendering software were analyzed.

Results

The area under the receiver operating characteristic (ROC) curve for WTS, SPS, WTV, SPV relevant to recurrence was 0.667, 0.727, 0.654, and 0.751 while analyses of ROC curves revealed optimal WTS, SPS, WTV, and SPV cut-off values to predict recurrence of 2.48 cm, 2.03 cm, 3,258 mm³ and 1,889 mm³, respectively. The association between SPS and SPV was the coefficient of determination (R ²) =0.59. Multivariate analysis showed that SPV >1,889 mm³ (P=0.016) and male (P=0.041) were significant predictors of OS whereas SPV >1,889 mm³ (P=0.001), male (P=0.003), and the serum carcinoembryonic antigen value (P=0.041) were significantly correlated with DFS. SPS, SPV as well as the combination of SPS and SPV were all significantly correlated with the prediction of OS and DFS, and the incidence of pathological invasive factors.

Conclusions

SPV and the integrated use of SPS and SPV was highly beneficial for the prediction of postoperative prognosis in c-I NSCLC.

Predictive accuracy of lepidic growth subtypes in early-stage adenocarcinoma of the lung by quantitative CT histogram and FDG-PET

OBJECTIVES

The aim of this study was to analyze the accuracy of computed tomography (CT) and F-18 fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT) to distinguish lepidic growth adenocarcinoma (LGA), including adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic-predominant adenocarcinoma, all of which have favorable survival outcomes, from the more aggressive and invasive non-LGA subtypes.

MATERIALS AND METHODS

We identified 225 patients with c-0/I adenocarcinoma of the lung who underwent PET/CT and 3DCT followed by complete resection. Maximum standardized uptake values (SUVmax) of FDG and several histogram parameters were analyzed. Histological grades were classified according to the predominant subtype (G1: lepidic; G3: micropapillary or solid; and G2: subtypes other than G1/G3).

RESULTS

The proportion of pathological invasive factors (lymphatic vessel involvement/blood vessel invasion/pleural invasion/lymph node metastasis) of patients with preinvasive adenocarcinoma, G1, G2, and G3 tumors were 0%, 3.6%, 48.0%, and 100%, respectively; p <  0.001). Multivariate analysis with CT-related parameters demonstrated that 75^th percentile CT attenuation value (75^th%, p <  0.001) and maximum CT attenuation value (maxCT, p =  0.009) were associated with incidence of non-LGA, whereas the value of SUVmax demonstrated a significant correlation (p <  0.001). When all patients were dichotomized according to ground-glass opacities (GGO)/solid-dominancy for CT maximum diameter, a significant correlation with non-LGA was shown in patients with solid-dominant tumor on SUVmax (p <  0.001) and with GGO-dominant tumor on 75^th% (p =  0.006) and maxCT (p =  0.007). The combination of one of the two significant histogram parameters and SUVmax revealed higher predictive performance for pathological high malignant features (positive pathological invasive factors, non-LGA, and the highly malignant subtype covering G2 with moderately or poorly-differentiated carcinoma and G3) than the individual use of either factor.

CONCLUSION

The 75^th%, maxCT, and SUVmax were highly useful in distinguishing LGA from non-LGA in c-0/I adenocarcinoma.

Clinicopathological characteristics of lung cancer mimicking organizing pneumonia on computed tomography-a novel radiological entity of pulmonary malignancy

OBJECTIVE

Lung cancer could be misdiagnosed as benign due to its atypical radiological findings or difficulty in the histological diagnosis. We intended to elucidate the clinicopathological features of such lung cancers.

METHODS

Between 2008 and 2011, we performed surgical resection for 564 consecutive patients with lung adenocarcinoma. Findings on thin-section computed tomography were reviewed for all patients, 13 of whom were found to have lung cancer mimicking organizing pneumonia. The radiological and clinicopathological features of lung cancer mimicking organizing pneumonia and other adenocarcinomas were evaluated.

RESULTS

Among 13 patients with lung cancer mimicking organizing pneumonia, 4 were men. The median age was 70 years (range 62-81 years). Six patients were followed up for more than 1 year (range 1-108 months) as their lesions were misdiagnosed as organizing pneumonia. Preoperative carcinoembryonic antigen was significantly high (P = 0.025), and maximum tumor dimension was significantly large for lung cancer mimicking organizing pneumonia (30 vs. 23.6 mm, P = 0.001). Pathologically, there was no vascular invasion (P = 0.012) and only one lymphatic invasion (P = 0.064). One case of lymph node metastasis to the N2 node was found due to misdiagnosis as organizing pneumonia for 9 years.

CONCLUSIONS

Basically, lung cancer mimicking organizing pneumonia was less invasive and showed slow growth. However, nodal metastasis could be found. Thus, radiological diagnosis based on the findings of thin-section computed tomography is valuable to avoid delay in diagnosis.

Low-Grade and High-Grade Mucoepidermoid Carcinoma of the Lung: CT Findings and Clinical Features of 17 Cases

OBJECTIVE

The objective of our study was to characterize the CT features and clinical findings of low-grade and high-grade mucoepidermoid carcinoma (MEC) of the lung.

MATERIALS AND METHODS

The CT findings and clinical information of 17 consecutive patients with primary low-grade (n = 11) or high-grade (n = 6) MEC were analyzed retrospectively. We assessed tumor location, size, contour, margin, density, calcification, obstructive changes, presence of metastasis, and enhancement.

RESULTS

In patients with low-grade MEC, tumor location was central in 10 and peripheral in one. In contrast, one and five tumors in patients with high-grade MEC were central and peripheral, respectively. There was a significant difference between central and peripheral locations among tumor grades (p = 0.005). In low-grade MECs, tumor contour was smoothly oval (n = 3) or spheric (n = 4); four were lobular. In five patients with low-grade MEC, tumors had well-defined margins; margins in the other six were poorly defined. Tumor density was homogeneous and heterogeneous in eight and three low-grade tumors, respectively. All six high-grade tumors had heterogeneous density, lobular contours, and poorly defined margins. Enhancement in both low-grade and high-grade tumors was greater than that of chest wall muscles, and low-grade tumors showed greater enhancement (46.90 ± 20.44 HU) than did high-grade tumors (22.50 ± 8.38 HU) (p = 0.015).

CONCLUSION

A markedly enhanced homogeneous central bronchial nodule or mass may suggest low-grade MEC. High-grade MEC tends to be peripheral, to have poorly defined margins, and to be lobular, heterogeneous nodules or masses with less enhancement.

Predictors of pathological non-invasive lung cancer with pure-solid appearance on computed tomography to identify possible candidates for sublobar resection

PURPOSE

This study aimed to establish favorable predictors for patients with clinical stage IA radiological pure-solid lung cancer to identify possible candidates for sublobar resection.

METHODS

We examined 275 patients with surgically resected clinical stage IA radiological pure-solid lung cancer. Pathological grade PL0, Ly0, V0, or N0 disease was defined as non-invasive pure-solid lung cancer (NIPS).

RESULTS

Nodal involvement was observed in 63 (23 %) patients with clinical stage IA pure-solid lung cancer, while NIPS was identified in 77 (28 %). Multivariate analysis revealed that air bronchogram (p = 0.0328), clinical T1a (p = 0.0041), and SUV_max (p = 0.0002) were significant clinical predictors of NIPS. When these clinical predictors were combined and the relevant patients' disease was classified as favorable, the frequency of nodal involvement was only 4 %. Furthermore, the 3-year overall survival (OS) of the patients with "favorable" clinical stage IA pure-solid lung cancer was 100 % despite their operative modes. In contrast, the 3-year OS even for patients with clinical stage IA disease, if they had neither of these clinical predictors, was 74.1 %.

CONCLUSIONS

Tumor size, the presence of air bronchogram, and the SUV_max level were significant favorable predictors of pathological non-invasive status, and patients with these clinical predictors could be candidates for sublobar resection for clinical stage IA pure-solid lung cancers.

What is the appropriate operative strategy for radiologically solid tumours in subcentimetre lung cancer patients?†

OBJECTIVES

Solid lung cancers, even subcentimetre lesions, are considered to be invasive pathologically. However, the clinicopathological features and appropriate operative strategies in patients with these small lesions are still controversial, especially for those with a radiologically solid appearance.

METHODS

Between 2004 and 2011, 135 patients underwent pulmonary resection for subcentimetre lung cancer with clinical-N0 (c-N0) status. The findings of preoperative thin-section computed tomography (CT) were reviewed, and subcentimetre lung cancer was divided into three groups: pure ground-glass nodule, part-solid and pure-solid lesions.

RESULTS

Among the 135 subcentimetre lung cancer patients with c-N0 status, 71 showed a solid appearance on thin-section CT scan. Furthermore, pathological nodal examinations were performed in 49 patients, and nodal involvement was found pathologically in 6 (12.2%) patients. All of them had pure-solid tumours (P = 0.0010). Among the patients with solid subcentimetre lung cancers, the maximum standardized uptake value (SUVmax) was the only significant predictor of nodal involvement by a multivariate analysis (P = 0.0205). With regard to the surgical outcomes, the overall 5-year survival and disease-free survival rates were 100 and 97.8% for part-solid lesions, and 87.3 and 74.8% for pure-solid lesions, respectively. Moreover, there was a significant difference in disease-free survival between a high SUVmax group (60.0%) and a low SUVmax group (94.9%) (P = 0.0013).

CONCLUSIONS

There might be a possibility of lymph node metastasis despite subcentimetre lung cancer, especially for radiological pure-solid nodules that show a high SUVmax. If limited surgery is indicated for solid subcentimetre lung cancer, a thorough intraoperative evaluation of lymph nodes is needed to prevent loco-regional failure.

Visceral pleural invasion is not a significant prognostic factor in patients with a part-solid lung cancer

BACKGROUND

Visceral pleural invasion (VPI) has been considered to be a prognostic factor. If a tumor shows VPI, it increases the T descriptor and upstages a tumor from stage IA to stage IB pathologically, even for those less than 30 mm in diameter. However, there is still some controversy regarding the prognostic significance of VPI in patients with radiologically early lung cancer with ground glass opacity.

METHODS

Between 2004 and 2012, 466 patients with surgically resected pathologic N0 non-small cell lung cancer less than 30 mm in diameter who showed a "part-solid" or "pure-solid" appearance on thin-section computed tomography scan were retrospectively reviewed. A Cox proportional hazard model was used to evaluate prognostic factors. Survival was calculated by the Kaplan-Meier method.

RESULTS

Two hundred thirty-seven patients (55%) showed part-solid and 209 (45%) showed pure-solid nodules on thin-section computed tomography scan. VPI was found in 24 (10%) part-solid nodules and 79 (38%) pure-solid nodules. On the basis of a multivariate analysis, VPI was not a significant prognostic factor in patients with part-solid nodules (p=0.5902). In this group, the 5-year survival rates in patients with and without VPI were 85.6% and 94.9%, respectively (p=0.3798). By contrast, VPI, vessel invasion, maximum tumor diameter, and carcinoembryonic antigen level were significant prognostic factors in patients with pure-solid nodules (p=0.0211, 0.0188, 0.0372, and 0.0492, respectively). Moreover, the 5-year survival in patients with VPI (70.1%) was significantly worse than that in patients without VPI (81.3%) among patients with pure-solid nodules (p=0.0051).

CONCLUSIONS

VPI may not contribute to the prognosis of patients with part-solid nodules. Thus, upgrading of the TNM stage on the basis of VPI should be carefully considered in these patients.

Tumour standardized uptake value on positron emission tomography is a novel predictor of adenocarcinoma in situ for c-Stage IA lung cancer patients with a part-solid nodule on thin-section computed tomography scan

OBJECTIVES

Adenocarcinoma in situ (AIS), which is considered to be pathologically non-invasive in the new International Association for the Study of Lung Cancer/the American Thoracic Society/the European Respiratory Society classification, might be present in patients who show a part-solid nodule on thin-section computed tomography (CT) scan.

METHODS

Between 2008 and 2011, 556 clinical Stage IA (c-Stage IA) lung cancer patients underwent pulmonary resection. For all the patients, the findings obtained by preoperative thin-section CT were reviewed and categorized as pure ground-glass nodule (GGN), part-solid nodule or pure-solid nodule based on the findings on thin-section CT, i.e. based on the consolidation/tumour ratio (CTR). A part-solid nodule was defined as a tumour with 0 < CTR < 1.0, which indicated focal nodular opacity that contained both solid and GGN components. All the patients were evaluated by positron emission tomography (PET), and the maximum standardized uptake value (SUVmax) was recorded. Several clinicopathological features were investigated to identify predictors of AIS in clinical Stage IA lung cancer patients with a part-solid nodule radiologically, using multivariate analyses.

RESULTS

One-hundred and twelve c-Stage IA lung cancer patients showed a part-solid appearance on thin-section CT. Among them, AIS was found in 10 (32%) of the tumours with 0 < CTR ≤ 0.5, in contrast to 3 (5%) with 0.5 < CTR < 1.0. According to multivariate analyses, SUVmax and CTR significantly predicted AIS in patients with a part-solid nodule (P = 0.04, 0.02). The mean SUVmax of the patients with AIS was 0.57 (0-1.6). Moreover, in the subgroup of part-solid nodule with a SUVmax of ≤1.0 and a CTR of ≤0.40, which were calculated as cut-off values for AIS based on the results for a receiver operating characteristic curve, 6 (40%) patients with these criteria showed a pathological non-invasive nature, even patients with a part-solid nodule.

CONCLUSIONS

Among c-Stage IA adenocarcinoma with a part-solid nodule on thin-section CT scan, an extremely low level of SUVmax could reflect a pure GGN equivalent radiologically and AIS pathologically. The preoperative tumour SUVmax on PET could yield important information for predicting non-invasiveness in patients with a part-solid nodule.

FDG PET/CT for the preoperative nodal staging of non-small cell lung cancer in a tuberculosis-endemic country: Are maximum standardized uptake values useful?

BACKGROUND

The aim of this study was to determine an optimum standardized uptake value threshold for identifying nodal metastasis in non-small cell lung cancer (NSCLC) patients using Fluorine-18 2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) in Taiwan, a tuberculosis-endemic country. The variation in standardized uptake values of nodal metastasis among different NSCLC histological subtypes was also evaluated.

METHODS

We retrospectively reviewed 75 NSCLC patients who had received FDG PET/CT before surgery. The diagnostic accuracy of FDG PET/CT for the preoperative nodal staging was evaluated by histopathologic findings.

RESULTS

A total of 316 nodal stations were evaluated. The sensitivity and specificity of FDG PET/CT for nodal staging were 58.6% and 81.8%, respectively, using an SUV cut-off of 2.6. With regard to the levels of mean SUVmax in true-positive and false-positive groups, there was no significant difference among different histological subtypes.

CONCLUSION

The present study demonstrated that FDG PET/CT for pre-operative nodal staging using SUVmax > 2.6 is a useful tool (with a higher specificity and a higher negative predictive value) to rule out the possibility of metastatic lymphadenopathy in operable patients with NSCLC.

Methods for staging non-small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Correctly staging lung cancer is important because the treatment options and prognosis differ significantly by stage. Several noninvasive imaging studies and invasive tests are available. Understanding the accuracy, advantages, and disadvantages of the available methods for staging non-small cell lung cancer is critical to decision-making.

METHODS

Test accuracies for the available staging studies were updated from the second iteration of the American College of Chest Physicians Lung Cancer Guidelines. Systematic searches of the MEDLINE database were performed up to June 2012 with the inclusion of selected meta-analyses, practice guidelines, and reviews. Study designs and results are summarized in evidence tables.

RESULTS

The sensitivity and specificity of CT scanning for identifying mediastinal lymph node metastasis were approximately 55% and 81%, respectively, confirming that CT scanning has limited ability either to rule in or exclude mediastinal metastasis. For PET scanning, estimates of sensitivity and specificity for identifying mediastinal metastasis were approximately 77% and 86%, respectively. These findings demonstrate that PET scanning is more accurate than CT scanning, but tissue biopsy is still required to confirm PET scan findings. The needle techniques endobronchial ultrasound-needle aspiration, endoscopic ultrasound-needle aspiration, and combined endobronchial ultrasound/endoscopic ultrasound-needle aspiration have sensitivities of approximately 89%, 89%, and 91%, respectively. In direct comparison with surgical staging, needle techniques have emerged as the best first diagnostic tools to obtain tissue. Based on randomized controlled trials, PET or PET-CT scanning is recommended for staging and to detect unsuspected metastatic disease and avoid noncurative resections.

CONCLUSIONS

Since the last iteration of the staging guidelines, PET scanning has assumed a more prominent role both in its use prior to surgery and when evaluating for metastatic disease. Minimally invasive needle techniques to stage the mediastinum have become increasingly accepted and are the tests of first choice to confirm mediastinal disease in accessible lymph node stations. If negative, these needle techniques should be followed by surgical biopsy. All abnormal scans should be confirmed by tissue biopsy (by whatever method is available) to ensure accurate staging. Evidence suggests that more complete staging improves patient outcomes.

Thoroughness of mediastinal staging in stage IIIA non-small cell lung cancer

INTRODUCTION

Guidelines recommend that patients with clinical stage IIIA non-small cell lung cancer (NSCLC) undergo histologic confirmation of pathologic lymph nodes. Studies have suggested that invasive mediastinal staging is underutilized, although practice patterns have not been rigorously evaluated.

METHODS

We used the Surveillance, Epidemiology, and End Results-Medicare database to identify patients with stage IIIA NSCLC diagnosed from 1998 through 2005. Invasive staging and use of positron emission tomography (PET) scanning were assessed using Medicare claims. Multivariable logistic regression was used to identify patient characteristics associated with use of invasive staging.

RESULTS

Of 7583 stage IIIA NSCLC patients, 1678 (22%) underwent invasive staging. Patients who received curative intent cancer treatment were more likely to undergo invasive staging than patients who did not receive cancer-specific therapy (30% versus 9.8%, adjusted odds ratio, 3.31; 95% confidence interval, 2.78-3.95). The oldest patients (age, 85-94 years) were less likely to receive invasive staging than the youngest (age, 67-69 years; 27.6% versus 11.9%; odds ratio, 0.46; 95% confidence interval, 0.34-0.61). Sex, marital status, income, and race were not associated with the use of the invasive staging. The use of invasive staging was stable throughout the study period, despite an increase in the use of PET scanning from less than 10% of patients before 2000 to almost 70% in 2005.

CONCLUSION

Nearly 80% of Medicare beneficiaries with stage IIIA NSCLC do not receive guideline adherent mediastinal staging; this failure cannot be entirely explained by patient factors or a reliance on PET imaging. Incentives to encourage use of invasive staging may improve care.

Relationship between peripheral lung cancer and the surrounding bronchi, pulmonary arteries, pulmonary veins: a multidetector CT observation

AIM

This study aimed to investigate the relationship between peripheral lung cancer and the surrounding pulmonary vessels and bronchi using contrast-enhanced multidetector computed tomography (MDCT) and to analyze associated factors such as pathology types, stage, size, density, and location of peripheral lung cancer.

MATERIALS AND METHODS

A total of 93 patients with solitary peripheral lung cancers underwent contrast-enhanced MDCT before thoracotomy were enrolled. Multiplanar reconstruction, maximal intensity projection, and volume rendering were used for demonstrating the patterns of the tumor-bronchi (Br), tumor-pulmonary artery (PA) and tumor-pulmonary vein (PV) relationship, respectively. Five subtypes were identified: Type1 (Br1, PA1 and PV1), Br, PA, or PV was erupted at the edge of nodule; Type2 (Br2, PA2, and PV2), erupted at the center of nodule; Type3 (Br3, PA3 and PV3), penetrated through the nodule; Type4, (Br4, PA4 and PV4), contacting the nodule but stretched or encased; Type5 (Br5, PA5, and PV5), contacting the nodule but smoothly compressed.

RESULTS

Both bronchi and PA were interrupted in 70 (Type 1+2); both narrowed in 9 (Type 3+4). The bronchi and PA changes surrounding the lung cancer had positive relations (χ(2)=12.3918, r=0.7524, P<.01). Br1 and PA1 were more often seen in the group of solid, ≥2.0 cm, and Stage II-IV focal lesions, while Br2 and PA2, more often in the group of part-solid, non-solid, <2.0 cm, and Stage I focal lesions. PV2 was more often seen in the part-solid and non-solid focal lesions group, while PV (4+5), more often in solid focal lesions group.

CONCLUSION

MDCT can demonstrate and subtype relationships among peripheral lung cancer and the bronchi, pulmonary arteries and pulmonary veins. This can be the basis for further clinical research and differential diagnosis.

Predictive factors of pathologically proven noninvasive tumor characteristics in T1aN0M0 peripheral non-small cell lung cancer

BACKGROUND

We retrospectively analyzed preoperative factors that may predict pathologically invasive tumor characteristics, including lymph node involvement, and pleural and vessel invasion in patients with cT1aN0M0 peripheral non-small cell lung cancer (NSCLC), in an attempt to identify candidates for pulmonary resection less than lobectomy.

METHODS

We reviewed the charts of 363 patients in whom cT1aN0M0 lung cancer in the lung periphery had been diagnosed or was suspected, based on high-resolution CT scan of 1- or 2-mm-slice intervals, within 1 month of surgical resection, and examined the relationships between preoperative clinical information and pathologic invasive tumor characteristics, corresponding to lymph node involvement and pleural and vessel invasion.

RESULTS

Multivariate analysis showed that a tumor disappearance ratio (TDR) < 0.5, the presence of spiculation, and an absence of air bronchograms were statistically significant independent predictors of pathologic invasiveness. Most TDR ≥ 0.5 tumors were noninvasive (98.7%), and only one patient had a recurrence within 5 years after surgical resection. Of the tumors with a TDR ≥ 0.5 without spiculation, 98.3% were noninvasive, and all those patients remained recurrence-free for 5 years after surgery.

CONCLUSION

The combination of a TDR ≥ 0.5 and the absence of spiculation was highly predictive of noninvasive or minimally invasive NSCLC. Future studies should evaluate whether limited resection of these tumors provides acceptable outcomes.

Impact of Lymphoid Follicles and Histiocytes on the False-Positive FDG Uptake of Lymph Nodes in Non-Small Cell Lung Cancer

PURPOSE

Although (18)F-fluorodeoxyglucose (FDG) PET/CT has improved the accuracy of evaluating lymph node (LN) staging in non-small cell lung cancer (NSCLC), false-positive results remain a problem. The reason why benign LNs show high FDG uptake is still unclear. The aim of this study was to identify molecular and pathological characteristics of benign LNs showing high FDG uptake.

MATERIALS AND METHODS

We studied 108 mediastinal LNs of pathologically benign nature obtained from 43 patients with NSCLC who underwent FDG PET/CT and surgery. We measured the following parameters in each LN: maximum standardized uptake value (maxSUV), short diameter, maximum Hounsfield unit (maxHU) value, occupied proportions of lymphoid follicles, histiocytes in extrafollicular space and the degree of glucose transporter 1 (Glut1) expression. We compared the parameters between two LN groups according to maxSUV.

RESULTS

There were 74 LNs showing maxSUV≥3.0 (group 1) and 34 LNs with maxSUV<3.0 (group 2). The size of LN (p < 0.001) and maxHU (p = 0.003) in group 1 was higher than that in group 2. Histologically, the occupied proportions of lymphoid follicles (p = 0.031) or histiocytes (p = 0.004) were higher in group 1. The Glut1 expression of lymphoid follicles (p = 0.035) or histiocytes (p = 0.005) was also higher in group 1.

CONCLUSION

Lymphoid follicular hyperplasia and histiocyte infiltration associated with Glut1 overexpression are important molecular and pathological mechanisms for false-positive FDG uptake in benign mediastinal LNs in patients with NSCLC.

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.

Hounsfield units upon PET/CT are useful in evaluating metastatic regional lymph nodes in patients with oesophageal squamous cell carcinoma

OBJECTIVES

This study evaluated the usefulness of measurements of X-ray attenuation (in Hounsfield units) obtained from unenhanced CT images for attenuation correction of the positron emission tomography (PET) data from PET/CT in the assessment of regional lymph node metastasis in oesophageal squamous cell carcinoma.

METHODS

17 patients with oesophageal squamous cell carcinoma underwent surgery after evaluation with PET/CT. After the excised lymph nodes were reviewed, we compared the histopathology and PET/CT findings, and analysed the lymph node metastasis. When 18-F fludeoxyglucose (FDG) uptake in the lymph nodes was focally prominent in comparison with background mediastinal activity (regardless of lymph node size), the lymph nodes were considered to be positive for malignancy by PET/CT. The mean Hounsfield units of mediastinal lymph nodes showing abnormally increased FDG uptake in PET/CT was retrospectively evaluated using images from the unenhanced CT component of PET/CT. Receiver operating characteristic (ROC) curve analysis was applied to determine the optimal cut-off value of mean Hounsfield units for detecting individual lymph node metastases.

RESULTS

For depiction of malignant nodal groups in each lymph node group, the sensitivity, specificity and accuracy of PET/CT based on increased FDG uptake were 58.8%, 74.5% and 70.8%, respectively. For patients with nodal groups that were positive for uptake by PET/CT, the mean attenuation in lymph nodes as measured by CT was 48 ± 13 HU for malignant nodes and 75 ± 18 HU for benign nodes. This difference was statistically significant (p<0.001). Using ROC curve analysis, we determined the cut-off as 71 HU. When we excluded lymph nodes with attenuation higher than 71 HU from the nodes determined as malignant by PET/CT, the specificity and accuracy for detecting metastatic lymph nodes improved to 90.9% and 83.3%, respectively.

CONCLUSIONS

When interpreting lymph node metastasis in oesophageal squamous cell carcinoma using PET/CT, the assumption that any lymph node with mean HU>71 is benign can improve diagnostic accuracy.

Joint use of cervical mediastinoscopy and video-assisted thoracoscopy for the evaluation of mediastinal lymph nodes in patients with non-small cell lung cancer

OBJECTIVE

To evaluate the efficacy of the joint use of cervical mediastinoscopy and video-assisted thoracoscopy for the sampling of mediastinal lymph nodes in patients with non-small cell lung cancer (NSCLC) and candidates for pulmonary resection.

METHODS

Sixty-two patients diagnosed with NSCLC were submitted to cervical mediastinoscopy and video-assisted thoracoscopy. The samples obtained (from paratracheal chains, anterior and posterior subcarinal chains, paraesophageal chains and pulmonary ligament) were submitted to frozen section analysis. The following variables were also evaluated: age; gender; weight loss; diagnostic method; tomographic findings; histological type; staging; and location and size of the primary tumor.

RESULTS

In 11 patients, mediastinoscopy showed no involvement of the subcarinal chain, whereas such involvement was identified when video-assisted thoracoscopy was used: positive predictive value = 88.89% (95% CI: 51.75-99.72); negative predictive value = 94.34% (95% CI: 84.34-98.82); prevalence = 17.74% (95% CI: 9.2-29.53); sensitivity = 72.73% (95% CI: 39.03-93.98); and specificity = 98.77% (95% CI: 93.31-99.97). In 60% of the patients with involvement of the posterior subcarinal chain, the primary tumor was in the right inferior lobe. (p = 0.029)

CONCLUSIONS

The joint use of cervical mediastinoscopy and video-assisted thoracoscopy for the evaluation of posterior mediastinal lymph nodes proved to be an efficacious method. When there is no access to posterior chains by means of ultrasound with transbronchial or transesophageal biopsy, which dispenses with general anesthesia, this should be the method of choice for the correct evaluation of mediastinal lymph nodes in patients with NSCLC.

Noninvasive staging of non-small cell lung cancer: ACCP evidenced-based clinical practice guidelines (2nd edition)

BACKGROUND

Correctly staging lung cancer is important because the treatment options and the prognosis differ significantly by stage. Several noninvasive imaging studies including chest CT scanning and positron emission tomography (PET) scanning are available. Understanding the test characteristics of these noninvasive staging studies is critical to decision making.

METHODS

Test characteristics for the noninvasive staging studies were updated from the first iteration of the lung cancer guidelines using systematic searches of the MEDLINE, HealthStar, and Cochrane Library databases up to May 2006, including selected metaanalyses, practice guidelines, and reviews. Study designs and results are summarized in evidence tables.

RESULTS

The pooled sensitivity and specificity of CT scanning for identifying mediastinal lymph node metastasis were 51% (95% confidence interval [CI], 47 to 54%) and 85% (95% CI, 84 to 88%), respectively, confirming that CT scanning has limited ability either to rule in or exclude mediastinal metastasis. For PET scanning, the pooled estimates of sensitivity and specificity for identifying mediastinal metastasis were 74% (95% CI, 69 to 79%) and 85% (95% CI, 82 to 88%), respectively. These findings demonstrate that PET scanning is more accurate than CT scanning. If the clinical evaluation in search of metastatic disease is negative, the likelihood of finding metastasis is low.

CONCLUSIONS

CT scanning of the chest is useful in providing anatomic detail, but the accuracy of chest CT scanning in differentiating benign from malignant lymph nodes in the mediastinum is poor. PET scanning has much better sensitivity and specificity than chest CT scanning for staging lung cancer in the mediastinum, and distant metastatic disease can be detected by PET scanning. With either test, abnormal findings must be confirmed by tissue biopsy to ensure accurate staging.

Early recurrence of completely resected N2-positive non-small-cell lung cancer

OBJECTIVE

Postoperative early recurrence, defined as recurrence within 1 year postoperatively, is often experienced with completely resected N2 disease. In this study, we evaluated the risk factors for early recurrence with completely resected N2 disease.

METHODS

. Potential risk factors for postoperative early recurrence were evaluated in 75 patients with N2 disease who underwent complete resection without any preoperative therapy. Prognostic significance was determined by univariate and multivariate analyses.

RESULTS

The median follow-up period was 24 months, and the 5-year survival rate was 23%. Thirty-nine patients developed postoperative early recurrence. The 1-, 3-, and 5-year survival rates of patients with early recurrence were 64%, 10%, and 5%, respectively, and 100%, 51%, and 34%, respectively (p < 0.001). Multistation N1 metastasis was a risk factor for postoperative early recurrence by univariate analysis and an independent risk factor by multivariate analysis.

CONCLUSIONS

Early recurrence is a significant poor prognostic factor for completely resected N2 disease. It is suggested that the number of N1 stations with metastasis is a risk factor for early recurrence and a poor prognostic factor in N2 disease.

Comparison of results of computed tomography and radiography with histopathologic findings in tracheobronchial lymph nodes in dogs with primary lung tumors: 14 cases (1999–2002)

OBJECTIVE

To compare results of computed tomography (CT) and radiography with histopathologic findings in tracheobronchial lymph nodes (TBLNs) in dogs with primary lung tumors.

DESIGN

Retrospective case series.

ANIMALS

14 client-owned dogs.

PROCEDURES

Criteria for inclusion were diagnosis of primary lung tumor, use of thoracic radiography and CT, and histologic confirmation of TBLN status. Medical records were reviewed for signalment; history; and physical examination, clinicopathologic, radiographic, CT, surgical, and histopathologic findings.

RESULTS

Tracheobronchial lymphadenopathy was not identified via radiography in any dogs. Tracheobronchial lymphadenopathy was diagnosed in 5 dogs via CT. Six dogs had histologic confirmation of metastasis to TBLNs. Radiographic diagnosis yielded 6 false-negative and no false-positive results for tracheobronchial lymphadenopathy. Computed tomography yielded 1 false-negative and no false-positive results. Sensitivity of CT for correctly assessing TBLN status was 83%, and specificity was 100%. Positive predictive value was 100%, and negative predictive value was 89%. Dogs with lymphadenopathy via CT, histologic confirmation of TBLN metastasis, or primary tumors with a histologic grade > 1 had significantly shorter survival times than their counterparts.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of CT evaluation of TBLN status were in agreement with histopathologic findings and more accurate than use of thoracic radiography for evaluating TBLNs in dogs with primary lung tumors. Computed tomography imaging should be considered as part of the staging process to more accurately assess the TBLNs in dogs with primary lung tumors.

Cáncer de pulmón no microcítico localmente avanzado

The objective of the treatment in stages III A and III B without pleural effusion should be both locoregional and distant disease control. We known that at least 80% of the patients had micrometastatic disease at the time of diagnosis, so that a treatment that is only local would be condemned to failure from the time it is suggested. Many clinical questions continue to exist and each step achieved is followed by a new diagnostic or therapeutic dilemma and is thus a fertile field for clinical research.

Problems in Diagnosis and Surgical Management of Clinical N1 Non-small Cell Lung Cancer

BACKGROUND

Clinical diagnosis of the nodal status is a significant factor in determining the treatment and predicting the prognosis in lung cancer patients. A patient with clinical N1 (cN1) disease is usually considered to be a candidate for surgical intervention in the present staging system in non-small cell lung cancer (NSCLC). However, cN1 disease is a subset for which the method of treatment and surgical results are variable, simply because both upstaging and downstaging can occur. We evaluated the surgical and pathologic results of cN1 NSCLC patients to reveal the problems in diagnosis and surgical management for this subset.

METHODS

From January 1998 to March 2003, 1,606 patients underwent thoracotomy for primary lung cancer at the National Cancer Center Hospital. Among them, the subjects for this study were 168 (10.5%) NSCLC patients who were clinically diagnosed as having N1 disease and underwent surgery without induction therapy.

RESULTS

The tumor cell types of these 168 cN1 NSCLC patients were adenocarcinoma in 73 (44%) and squamous cell carcinoma in 79 (47%). Pneumonectomy was performed in 26% (n = 43) patients, bilobectomy in 15% (n = 25), and exploratory thoracotomy in 11% (n = 19). Of 19 exploratory thoracotomy cases, 10 cases were due to pleural dissemination. The pathologic nodal status of the 135 patients who underwent pulmonary resection and mediastinal dissection was pN0, 19% (n = 25); pN1, 44% (n = 59); and pN2-3, 37% (n = 51). Of the 55 adenocarcinomas, 60% (n = 33) were revealed to be N2 disease on pathologic examination. There were no significant differences in the serum tumor markers between the pN1 and pN2 groups. Among the 25 patients who were downstaged postoperatively (cN1-pN0), 21 patients (84%) showed obstructive pneumonia in the lung.

CONCLUSIONS

In the staging process of cN1 disease, it will be helpful to perform mediastinoscopy and thoracoscopy to avoid unnecessary thoracotomy especially in adenocarcinoma, even though mediastinal nodes and pleural dissemination were negative on computed tomography investigation. Since extensive pulmonary resection (bilobectomy or pneumonectomy) was required in 41% of the patients, preoperative detailed cardiopulmonary function tests should be mandatory to reduce surgical morbidity and mortality. On the other hand, when pneumonia due to airway obstruction by the tumor exists, false-positive hilar nodes can be expected.

Pitfalls in lymph node staging with positron emission tomography in non-small cell lung cancer patients

BACKGROUND

The evidence of clinical value of positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) in lymph node (LN) staging in non-small cell lung cancer (NSCLC) has been shown in numerous papers. However, few studies have assessed its limitations. The aim of the present study is to clarify clinico-pathologic factors responsible for false PET results.

METHODS

From July 2000 through December 2001, 71 NSCLC patients underwent both FDG PET and surgical intervention at the National Cancer Center Hospital East, Chiba. Clinical records, computed tomographic (CT) scan findings, PET findings, and histologic findings were retrospectively reviewed.

RESULTS

Sensitivity, specificity, accuracy in nodal staging for CT were 29, 83, and 65% and for PET were 39, 79, and 66%, respectively. There were 10 (14%) false-positive PET scans and 14 (20%) false-negative PET scans. The causative factors for false-positive PET scan were: (1) inflammatory conditions in seven patients; (2) PET mis-localization of an interlobar LN as a mediastinal LN in one patient; (3) inability to distinguish the endobronchial polypoid growth of a primary tumor from a lobar LN in one patient; (4) unknown in one patient. All false-positive LNs due to inflammatory conditions showed reactive lymphoid hyperplasia histologically. The causative factors for false-negative PET scan were: (1) limitation of spatial resolution of the PET scanner in 12 patients (maximum tumor focus dimensions in false-negative LNs ranging from 1 to 7.5 mm, with an average of 3.4 mm); (2) PET mis-localization of a mediastinal LN as a hilar LN in one patient; (3) weak FDG uptake by microscopic tumor foci due to necrosis with massive bleeding in a metastatic LN in one patient.

CONCLUSIONS

Inflammatory conditions were most responsible for false-positive PET scans, and spatial resolution limitation of FDG PET was the causative factor of false-negative PET scans. Recognizing these factors in advance would be clinically helpful in accurate nodal staging with FDG PET.

Cost-effectiveness analysis of strategies introducing FDG-PET into the mediastinal staging of non-small-cell lung cancer from the French healthcare system perspective

AIM

To determine the most cost-effective strategy using PET for mediastinal staging of potentially operable non-small-cell lung cancer (NSCLC).

METHODS

Four decision strategies based on French NSCLC work-up practices for the selection of potential surgical candidates were compared, comprising CT only, PET for negative CT, PET for all with anatomical CT, and CT and PET for all cases. The medical literature was surveyed to obtain values for all variables of interest. Costs were assessed with reimbursements from the French healthcare insurance for the year 1999. Expected cost and life expectancy were calculated for all possible outcomes of each strategy. Sensitivity analysis was performed to determine the effects of changing variables on the expected cost and life expectancy.

RESULTS

Compared with the CT only strategy, CT and PET for all resulted in a relative reduction of 70% of surgery for persons with mediastinal lymph node metastasis. PET for all with anatomical CT was shown to be a cost-effective alternative to the CT only, with life expectancy increased by 0.10 years and expected cost savings of 61 euros. This strategy was more favourable than PET for negative CT. Overall, sensitivity analyses showed the robustness of the results.

CONCLUSION

The introduction of thoracic PET for NSCLC staging is potentially cost-effective in France. Further clinical investigation might help to validate this result.

Surgical exploration of the mediastinum: mediastinoscopy and intraoperative staging

Lung resection remains the therapy of choice offering the greatest potential for cure in non-spread lung cancer. Prognostic importance of lymph-node involvement has been underlined by several studies. So, exploration of the mediastinum is of major importance for defining the therapeutic strategy in a possibly curative setting. Pre-resectional exploration of the mediastinal lymph-nodal status is mandatory to define tumour stage exactly and establish specific therapy. Cervical mediastinoscopy is the primary diagnostic procedure and remains the gold standard in invasive surgical staging. Complementary, parasternal mediastinoscopy, extended mediastinoscopy, and video-assisted thoracoscopy may be performed. These techniques allow accurate assessment of mediastinal lymph-node involvement, resulting in an appropriate judgement as to resectability and possible treatment options. Different techniques are established for intraoperative exploration and staging. In terms of curative surgery of lung cancer we demand accurate staging which is achieved by systematic and complete Lymph-node dissection. So, individually and dependent on primary tumour site, accurate mediastinal staging of Lung cancer should be performed in combination with definitive lung resection.

A prospective study of indications for mediastinoscopy in lung cancer with CT findings, tumor size, and tumor markers

BACKGROUND

Biopsies by mediastinoscopy remain the most reliable preoperative staging method for N2 lung cancer. Because it is neither practical nor economical to recommend mediastinoscopy for all candidates for surgery, we developed indicational criteria for video-assisted mediastinoscopy (VAM) and carried out a prospective study to validate its usefulness.

METHODS

Patients with resectable primary lung cancer were chosen for VAM when at least one of three clinical indicators was present: (1) computed tomographic evidence of mediastinal adenopathy, (2) elevated levels of serologic tumor markers, and (3) diameters of primary cancers (> 2 to 3 cm). Patients without positive nodes (group 2) underwent thoracotomy, and patients with positive nodes (group 3) received induction therapy. When none of these criteria were met (group 1), thoracotomy with R2b lymph node dissection was performed without VAM.

RESULTS

One hundred twenty-one men and 82 women (total, 203) were eligible for the study. The mean age of the patients was 64.4 years (range, 39 to 75 years) with primary lung cancer. The patients were comprised of 135 adenocarcinomas, 46 squamous cell cancers, and 22 other carcinomas. There were 78 patients in group 1, 87 in group 2, and 38 in group 3. The stages of group 2 patients were more advanced (chi2 = 63.2668; p < 0.001) than those of group 1. As the incidence of positive indicators for VAM increased, the ratios of N2 patients increased from 2.5% (all negative) to 90.4% (triple positive: p < 0.001). The correlation of our criteria with the pathology findings revealed a diagnostic sensitivity of 95.8% and a negative predictive value of 97.4%. Using three indicators for N2 prediction, we selected 96% (46 of 48) pN2, N3 patients and avoided 37% (76 of 203) unnecessary VAMs.

CONCLUSIONS

We established and validated currently useful criteria for VAMs in the management of primary lung cancer.

Noninvasive staging of non-small cell lung cancer: a review of the current evidence

STUDY OBJECTIVES

To determine the test performance characteristics of CT scanning, positron emission tomography (PET) scanning, MRI, and endoscopic ultrasound (EUS) for staging the mediastinum, and to evaluate the accuracy of the clinical evaluation (ie, symptoms, physical findings, or routine blood test results) for predicting metastatic disease in patients in whom non-small cell lung cancer or small cell lung cancer is diagnosed.

DESIGN, SETTING, AND PARTICIPANTS

Systematic searches of MEDLINE, HealthStar, and Cochrane Library databases to July 2001, and of print bibliographies. Studies evaluating the staging results of CT scanning, PET scanning, MRI, or EUS, with either tissue histologic confirmation or long-term clinical follow-up, were included. The performance of the clinical evaluation was compared against the results of brain and abdominal CT scans and radionuclide bone scans.

MEASUREMENT AND RESULTS

Pooled sensitivities and specificities for staging the mediastinum were as follows: for CT scanning: sensitivity, 0.57 (95% confidence interval [CI], 0.49 to 0.66); specificity, 0.82 (95% CI, 0.77 to 0.86); for PET scanning: sensitivity, 0.84 (95% CI, 0.78 to 0.89); specificity, 0.89 (95% CI, 0.83 to 0.93); and for EUS: sensitivity, 0.78 (95% CI, 0.61 to 0.89); specificity, 0.71 (95% CI, 0.56 to 0.82). For the evaluation of brain metastases, the summary estimate of the negative predictive value (NPV) of the clinical neurologic evaluation was 0.94 (95% CI, 0.91 to 0.96). For detecting adrenal and/or liver metastases, the summary NPV of the clinical evaluation was 0.95 (95% CI, 0.93 to 0.96), and for detecting bone metastases, it was 0.90 (95% CI, 0.86 to 0.93).

CONCLUSIONS

PET scanning is more accurate than CT scanning or EUS for detecting mediastinal metastases. The NPVs of the clinical evaluations for brain, abdominal, and bone metastases are > or = 90%, suggesting that routinely imaging asymptomatic lung cancer patients may not be necessary. However, more definitive prospective studies that better define the patient population and improved reference standards are necessary to more accurately assess the true NPV of the clinical evaluation.

Lung cancer staging

Accurate staging of lung cancer is essential for proper treatment and management of the disease, and allows predictions for patient survival. Several different invasive and noninvasive modalities exist for staging, and the determination of the best approach of one or a combination of those methods depends on the clinical situation and the clinician's assessment of the most appropriate means of staging evaluation. This review discusses the elements and framework of lung cancer staging, with particular emphasis on those newer modalities, especially positron emission tomography and endoscopic ultrasound needle biopsy, which will be expected to be used increasingly more common in clinical practice.

A surface-modified chylomicron remnant-like emulsion for percutaneous computed tomography lymphography: synthesis and preliminary imaging findings

RATIONALE AND OBJECTIVES

To assess a surface-modified emulsion as a percutaneous CT lymphographic agent in normal dogs.

METHODS

An iodinated chylomicron remnant-like microemulsion was formulated with a mean particle size of 91.3 nm and an iodine concentration of 91 mg I/mL. Contrast material (2 mL) was injected into the subcutaneous tissues of the metatarsus and metacarpus of six normal dogs to enhance popliteal and cervical lymph nodes, respectively. CT images were acquired at 0, 15, 30, 45, 60, 240, 480, and 1440 minutes.

RESULTS

Significant lymph node enhancement occurred in as little as 15 minutes after injection and persisted at least 8 hours. Node opacification was most pronounced at 1 to 4 hours postinjection and exceeded 200 HU in some nodes (precontrast attenuation = 45 HU). Marked enhancement of popliteal efferent lymphatics and of iliac and sacral node groups also occurred indicating distribution to second order nodes. Attenuation of enhanced nodes reverted to precontrast levels by 24 hours.

CONCLUSION

The new surface-modified, chylomicron remnant-like emulsion provided marked, selective enhancement of targeted lymph nodes after subcutaneous administration. Moreover, the formulation produced significant opacification of more distant node groups from a single injection.

Pathologic N0 status in pulmonary adenocarcinoma is predictable by combining serum carcinoembryonic antigen level and computed tomographic findings

OBJECTIVES

It is not clear whether lymphadenectomy has therapeutic benefit in non-small cell lung cancer management. To avoid unnecessary lymphadenectomy, we attempted to identify clinical or radiologic predictors of pathologic N0 disease in patients with peripheral adenocarcinoma.

METHODS

From August 1992 through April 1997, 269 consecutive patients with peripheral adenocarcinoma who underwent major lung resection and systematic lymph node dissection were enrolled in this study. We reviewed their contrast-enhancement computed tomographic scans and recorded the maximum dimension of tumors both on pulmonary (pDmax) and on mediastinal (mDmax) window setting images, the largest dimension perpendicular to the maximum axis on both pulmonary (pDperp) and mediastinal (mDperp) window setting images, and the size of all detectable hilar-mediastinal lymph nodes. We defined a new radiologic parameter, tumor shadow disappearance rate (TDR), which is calculated with the following formula: TDR = 1 - (mDmax x mDperp)/(pDmax x pDperp).

RESULTS

In multivariable analysis a lower serum carcinoembryonic antigen level and a higher tumor shadow disappearance rate were significant predictors of pathologic N0 disease. Lymph node size on computed tomographic scanning was not a significant predictor. Among 59 patients with a normal preoperative carcinoembryonic antigen level and a tumor shadow disappearance rate of 0.8 or more, 58 (98%) patients had pathologic N0 disease, and the other patient had pathologic N1 disease.

CONCLUSIONS

Mediastinal lymph node involvement was not found in patients with a normal preoperative serum carcinoembryonic antigen level and a tumor shadow disappearance rate 0.8 or more. The patients who meet these criteria may be successfully managed with major lung resection without systematic mediastinal lymphadenectomy.