Metastases from non-small cell lung cancer: mediastinal staging in the 1990s--meta-analytic comparison of PET and CT

NOX4 promotes non-small cell lung cancer cell proliferation and metastasis through positive feedback regulation of PI3K/Akt signaling

NADPH oxidase 4 (NOX4) is deregulated in various cancers and involved in cancer proliferation and metastasis. However, what the role of NOX4 plays during malignant progression of non-small cell lung cancer (NSCLC) remains unknown. Our results show that NOX4 was upregulated in NSCLC cell lines and samples from patients, compared with controls; NOX4 protein levels were closely correlated with clinical disease stage and survival time. Overexpression of NOX4 in A549 and H460 NSCLC cells enhanced cell proliferation and invasion in vitro, and produced larger tumors, shorter survival time, and more lung metastasis in nude mice than control cells. On the contrary, NOX4 depletion inhibited NSCLC cell aggressiveness. Inhibition of PI3K/Akt pathway could sufficiently block the cellular effects of NOX4 overexpression in NSCLC cells both in vitro and in vivo. Specifically, we demonstrated that PI3K/Akt pathway also positively regulated NOX4 expression via NF-κB-mediated manner. Therefore, there existed a mutual positive regulation between NOX4 and PI3K/Akt signaling in NSCLC cells, and NOX4 was confirmed to functionally interplay with PI3K/Akt signaling to promote NSCLC cell proliferation and invasion. In conclusion, the positive feedback loop between NOX4 and PI3K/Akt signaling contributes to NSCLC progression.

The usefulness of combined axial and coronal computed tomography for the evaluation of metastatic supraclavicular lymph nodes

The purpose is to assess the value of adding coronal images for the identification of metastatic supraclavicular lymph nodes (LNs). Two radiologists reviewed axial images and combined axial and coronal images using thoracic computed tomography (CT) of 386 patients whose maximum standardized uptake value measured in a supraclavicular LN was ≥2.0 on a positron emission tomography. We compared sensitivity and agreement between readers before and after the addition of coronal images. For combined images, agreement was almost perfect (κ=0.982), and sensitivity was significantly higher (90.4%, P<.001). Interpreting both axial and coronal images improves the diagnostic accuracy for supraclavicular metastasis.

Endoscopic ultrasonography-fine needle aspiration versus PET-CT in undiagnosed mediastinal and upper abdominal lymphadenopathy: a comparative clinical study

BACKGROUND AND STUDY AIMS

The wide use of PET-CT for the staging of neoplasms has extended to enlarged lymph nodes of unknown origin. Nevertheless, upper abdominal and mediastinal nodes are accessible to endoscopic ultrasonography-fine needle aspiration (EUS-FNA), providing a cytological diagnosis, with a high diagnostic yield in previous reports. In this paper, we have compared the accuracy of both procedures in this particular setting.

PATIENTS AND METHODS

After the finding of a lymphadenopathy in a conventional CT, both PET-CT and EUS-FNA were performed. The endoscopist had no information about PET-CT results. FNA was performed after a systematic EUS exam, with a 25 G needle and no suction. We considered the pathologic results as the gold standard or, if not available, the patients' outcome as a surrogate marker.

RESULTS

A total of 54 patients were included. Common locations of nodes included subcarinal space (33.3%), porta hepatis (31.5%), upper mediastinum (15%), peripancreatic (7.4%), and other locations (12.8%). Adequate specimens were obtained in 48/54 patients (89%). The most common diagnoses based on cytology were benign/reactive (42%), epidermoid carcinoma (8.4%), lymphoma (8.4%), and ductal adenocarcinoma of pancreatic origin (6.3%). PET was positive in 67% of patients. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of EUS-FNA were 91.3, 100, 100, 92.5, and 95.8%, respectively. The same values for PET-CT were 75, 25, 50, 50, and 50%, respectively.

CONCLUSION

In our series, EUS-FNA has proven to be the best diagnostic procedure to accurately establish the etiology of isolated adenopathies, showing a much better diagnostic yield than PET-CT, the role of which should be re-evaluated in this setting.

Computed tomography: revolutionizing the practice of medicine for 40 years

Computed tomography (CT) has had a profound effect on the practice of medicine. Both the spectrum of clinical applications and the role that CT has played in enhancing the depth of our understanding of disease have been profound. Although almost 90 000 articles on CT have been published in peer-reviewed journals over the past 40 years, fewer than 5% of these have been published in Radiology. Nevertheless, these almost 4000 articles have provided a basis for many important medical advances. By enabling a deepened understanding of anatomy, physiology, and pathology, CT has facilitated key advances in the detection and management of disease. This article celebrates this breadth of scientific discovery and development by examining the impact that CT has had on the diagnosis, characterization, and management of a sampling of major health challenges, including stroke, vascular diseases, cancer, trauma, acute abdominal pain, and diffuse lung diseases, as related to key technical advances in CT and manifested in Radiology.

Risk factors for mediastinal lymph node metastasis in non-small-cell lung cancer by PET/CT

OBJECTIVE

The aim of this study was to investigate the relationship between mediastinal lymph node metastasis based on fluorine-18 fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (PET/CT) of the primary tumor and various clinical indexes to determine the risk factors for malignant lymph nodes in non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

A total of 130 patients with histologically proven NSCLC who had not received any therapy underwent (18)F-FDG PET/CT for staging. The relationship between node metastasis, sex, age, smoking status, primary tumor maximum standardized uptake value (SUV(max)), size, pathological type, and differentiation was studied by univariate analyses, and risk factors for nodal metastasis in NSCLC were assessed by multivariate logistic regression.

RESULTS

Of the 130 patients, 68 were seen to have nodal metastasis on histological analysis. Nodal metastasis was correlated with SUV(max), size, and differentiation of primary lung lesions (P<0.05), and all the other factors were nonsignificant (P>0.05). On multivariate logistic regression analysis, the only independent factor was SUV(max) of the primary tumor, and the optimal cutoff value was 9.3 (sensitivity: 75.41%, 95% confidence interval: 62.7-85.5; specificity: 54.41%, 95% confidence interval: 41.9-66.5).

CONCLUSION

The mediastinal lymph node metastasis ratio was correlated with SUV(max), size, and differentiation in primary lung lesions. SUV(max) was the only independent predictor of lymph node metastasis in NSCLC. Video Abstract: http://links.lww.com/NMC/A22.

PET-based radiation therapy planning

In this review, we review the literature on the use of PET in radiation treatment planning, with an emphasis on describing our institutional methodology (where applicable). This discussion is intended to provide other radiation oncologists with methodological details on the use of PET imaging for treatment planning in radiation oncology, or other oncologists with an introduction to the use of PET in planning radiation therapy.

Unexpected lymph node disease in resections for pulmonary metastases

BACKGROUND

Pulmonary metastasectomy is widely accepted for different malignant diseases. The role of mediastinal lymph node (LN) dissection in these procedures is discussed controversially. We evaluated our results of LN removal at the time of pulmonary metastasectomy with respect to the frequency of unexpected LN disease.

METHODS

This was a retrospective analysis of 313 resections performed in 209 patients. Operations were performed in curative intention. Patients with known thoracic LN involvement and those without lymphadenectomy (n = 43) were excluded. Patients were analyzed according the type of LN dissection. Subgroups of different primary cancers were evaluated separately.

RESULTS

Sublobar resections were performed in 256 procedures with lymphadenectomy, and 14 patients underwent lobectomy. Patients underwent radical lymphadenectomy (n = 158) or LN sampling (n = 112). The overall incidence of unexpected tumor in LN was 17% (radical lymphadenectomy, 15.8%; sampling, 18.8%). Unexpected LN involvement was found in 17 patients (35.5%) with breast cancer, in 120 (9.2%) with colorectal cancer, and in 53 (20.8%) with renal cell carcinoma. The 5-year survival was 30.2% if LN were tumor negative and 25% if positive (p = 0.19). LN sampling vs radical removal had no significant effect on 5-year survival (23.6% vs 30.9%; p = 0.29).

CONCLUSIONS

Dissection of mediastinal LN in resection of lung metastases will reveal unexpected LN involvement in a relevant proportion of patients, in particular in breast and renal cancer. Routine LN dissection appears necessary and may become important for further therapeutic decisions. On the basis of our data, LN sampling seems to be sufficient.

Relationships between EGFR mutation status of lung cancer and preoperative factors - are they predictive?

BACKGROUND

The epidermal growth factor receptor (EGFR) mutation status of lung cancer is important because it means that EGFR-tyrosine kinase inhibitor treatment is indicated. The purpose of this prospective study is to determine whether EGFR mutation status could be identified with reference to preoperative factors.

MATERIALS AND METHODS

One hundred-forty eight patients with lung cancer (111 adenocarcinomas, 25 squamous cell carcinomas and 12 other cell types) were enrolled in this study. The EGFR mutation status of each lung cancer was analyzed postoperatively.

RESULTS

There were 58 patients with mutant EGFR lung cancers (mutant LC) and 90 patients with wild-type EGFR lung cancers (wild-type LC). There were significant differences in gender, smoking status, maximum tumor diameter in chest CT, type of tumor shadow, clinical stage between mutant LC and wild-type LC. EGFR mutations were detected only in adenocarcinomas. Maximum standardized uptake value (SUVmax:3.66±4.53) in positron emission tomography-computed tomography of mutant LC was significantly lower than that (8.26±6.11) of wild-type LC (p<0.0001). Concerning type of tumor shadow, the percentage of mutant LC was 85.7% (6/7) in lung cancers with pure ground glass opacity (GGO), 65.3%(32/49) in lung cancers with mixed GGO and 21.7%(20/92) in lung cancers with solid shadow (p<0.0001). For the results of discriminant analysis, type of tumor shadow (p=0.00036) was most significantly associated with mutant EGFR. Tumor histology (p=0.0028), smoking status (p=0.0051) and maximum diameter of tumor shadow in chest CT (p=0.047) were also significantly associated with mutant EGFR. The accuracy for evaluating EGFR mutation status by discriminant analysis was 77.0% (114/148).

CONCLUSIONS

Mutant EGFR is significantly associated with lung cancer with pure or mixed GGO, adenocarcinoma, never-smoker, smaller tumor diameter in chest CT. Preoperatively, EGFR mutation status can be identified correctly in about 77 % of lung cancers.

(18)F-fluorodeoxyglucose positron emission tomography/computed tomography accuracy in the staging of non-small cell lung cancer: review and cost-effectiveness

Aim of the performed clinical study was to compare the accuracy and cost-effectiveness of PET/CT in the staging of non-small cell lung cancer (NSCLC). Material and Methods. Cross-sectional and prospective study including 103 patients with histologically confirmed NSCLC. All patients were examined using PET/CT with intravenous contrast medium. Those with disease stage ≤IIB underwent surgery (n = 40). Disease stage was confirmed based on histology results, which were compared with those of PET/CT and positron emission tomography (PET) and computed tomography (CT) separately. 63 patients classified with ≥IIIA disease stage by PET/CT did not undergo surgery. The cost-effectiveness of PET/CT for disease classification was examined using a decision tree analysis. Results. Compared with histology, the accuracy of PET/CT for disease staging has a positive predictive value of 80%, a negative predictive value of 95%, a sensitivity of 94%, and a specificity of 82%. For PET alone, these values are 53%, 66%, 60%, and 50%, whereas for CT alone they are 68%, 86%, 76%, and 72%, respectively. Incremental cost-effectiveness of PET/CT over CT alone was €17,412 quality-adjusted life-year (QALY). Conclusion. In our clinical study, PET/CT using intravenous contrast medium was an accurate and cost-effective method for staging of patients with NSCLC.

Absence of a relationship between tumor ¹⁸F-fluorodeoxyglucose standardized uptake value and survival in patients treated with definitive radiotherapy for non-small-cell lung cancer

Introduction:

A recent meta-analysis suggested that patients with non–small-cell lung cancer (NSCLC) whose primary tumors have a higher standardized uptake value (SUV) derived from ¹⁸F-fluorodeoxyglucose positron emission tomography (PET) have a worse prognosis in comparison with those with tumors with lower values. However, previous analyses have had methodological weaknesses. Furthermore, the prognostic significance over the full range of SUV values in patients treated nonsurgically remains unclear. The aim of this retrospective study was to investigate the relationship between survival and maximum SUV (SUV_max) analyzed as a continuous variable, in patients with NSCLC, staged using PET/computed tomography (CT) and treated with radiotherapy with or without chemotherapy.

Methods:

Eligible patients had a histological diagnosis of NSCLC, were treated with radical radiotherapy with or without chemotherapy as their primary treatment, and had pretreatment PET/CT scans. SUV_max, defined as the maximum pixel SUV value retrieved from the primary tumor, was analyzed primarily as a continuous variable for overall survival.

Results:

Eighty-eight patients met eligibility criteria: stage I, 19; stage II, 10; and stage III, 59. Median SUV_max was 15.0 (range, 2.5–56). Higher stage was associated with higher SUV_max values (p = 0.048). In univariate analysis, there was no evidence of a prognostic effect of SUV_max (hazard ratio per doubling = 0.83; 95% confidence interval, 0.62–1.11; p = 0.22). Analyzing SUV_max as a dichotomous variable (median cut point = 15.0), the hazard ratio (high: low) for risk of death was 0.71, with p = 0.18 (95% confidence interval, 0.44–1.15).

Conclusions:

In this cohort of patients, increasing SUV_max derived from ¹⁸F-fluorodeoxyglucose–PET/CT was associated with increasing tumor, node, metastasis (TNM) stage. We found no evidence of an association of increasing SUV_max with a shorter survival. Previous reports of an association between prognosis and SUV_max may partly be the result of methodological differences between this study and previous reports and an association between stage and SUV_max.

Magnetic resonance imaging diagnosis of metastatic lymph nodes in a rabbit model: efficacy of PJY10, a new ultrasmall superparamagnetic iron oxide agent, with monodisperse iron oxide core and multiple-interaction ligands

Background

Accurate diagnosis of lymph node metastasis is crucial in treatment planning for cancer patients. Despite the use of various parameters, making correct diagnosis of a small metastatic or a hyperplastic benign node is still a challenge. In this study, we evaluated the feasibility of detecting lymph node metastasis using a new ultrasmall superparamagnetic iron oxide particle, PJY10, in a rabbit model.

Methods

To make metastatic and benign lymph nodes, either VX2 carcinoma or fecal material suspension was inoculated into thighs of 56 rabbits three weeks or three days before magnetic resonance (MR) imaging, respectively. T2*-weighted 3T MR imaging was performed before and 24 hours after PJY10 injection (5.2 [n = 15], 7.8 [n = 17], and 10.4 [n = 24] mg Fe/kg). MR images were correlated with pathologic results to calculate sensitivity and specificity. Quantitative analysis of the signal intensity (SI) – number of voxels_[low] (the fraction of the number of voxels with the normalized SI on the postcontrast image lower than that on the precontrast image) and mean SI ratio – was also performed for each lymph node.

Results

Sensitivities were 100% at all three dosages, whereas specificity increased with increasing dosage (89% at 10.4 mg Fe/kg). The benign nodes had a significantly higher number of voxels_[low] and a lower mean SI ratio than the metastatic nodes at the dosage of 10.4 mg Fe/kg (P<.001). Az values were 0.905 for the number of voxels_[low] and 0.952 for the mean SI ratio. The number of voxels_[low] (P = .019) and the mean SI ratio (P = .034) had significant correlations with the histopathologic area ratio of metastatic foci in the metastatic nodes at 10.4 mg Fe/kg.

Conclusions

PJY10 enabled clear demonstration of lymph node metastasis with high sensitivity and specificity at its optimal dosage of 10.4 mg Fe/kg.

Prognostic value of volumetric parameters of (18)F-FDG PET in non-small-cell lung cancer: a meta-analysis

PURPOSE

We conducted a comprehensive systematic review of the literature on volumetric parameters from (18)F-FDG PET and a meta-analysis of the prognostic value of metabolic tumour volume (MTV) and total lesion glycolysis (TLG) in patients with lung cancer.

METHODS

A systematic search of MEDLINE and EMBASE was performed using the keywords "positron emission tomography (PET)", "lung cancer", and "volume". Inclusion criteria were: (18)F-FDG PET used as an initial imaging tool; studies limited to non-small-cell lung cancer (NSCLC); volume measurement of lung cancer; patients who had not undergone surgery, chemotherapy, or radiotherapy before the PET scan; and studies that reported survival data. Event-free survival and overall survival were evaluated as outcomes. The impact of MTV and TLG on survival was measured in terms of the hazard ratio (HR) effect size. Data from each study were analysed using Review Manager 5.2.

RESULTS

Thirteen eligible studies including 1,581 patients were analysed. Patients with high MTV showed a worse prognosis with an HR of 2.71 (95% CI 1.82 - 4.02, p < 0.00001) for adverse events and an HR of 2.31 (95% CI 1.54 - 3.47, p < 0.00001) for death. Patients with high TLG also showed a worse prognosis with an HR of 2.35 (95% CI 1.91 - 2.89, p < 0.00001) for adverse events and an HR of 2.43 (95% CI 1.89 - 3.11, p < 0.00001) for death. The prognostic value of MTV and TLG remained significant in a subgroup analysis according to TNM stage as well as the methods for defining cut-off values and tumour delineation.

CONCLUSION

Volumetric parameters from (18)F-FDG PET are significant prognostic factors for outcome in patients with NSCLC. Patients with a high MTV or TLG are at higher risk of adverse events and death. MTV and TLG were significant prognostic factors in patients with TNM stage I/II and stage III/IV NSCLC.

Predictive value of 18F-fluorodeoxyglucose positron emission tomography - computed tomography compared to postoperative pathological findings for patients with non-small-cell lung cancer

This study was conducted to investigate the predictive value of ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET-CT) in patients with non-small-cell lung cancer (NSCLC), compared to that of postoperative pathological findings, for T and N staging and the associations of the metabolic parameters of the primary tumor with histological type and differentiation. The preoperative contrast-enhanced CT and ¹⁸F-FDG PET-CT and postoperative pathological findings of 112 NSCLC patients treated with lobectomy or pneumonectomy combined with systematic mediastinal lymphadenectomy were retrospectively reviewed. Compared to the postoperative pathological findings, the effect of contrast-enhanced CT and ¹⁸F-FDG PET-CT on T and N staging were evaluated. The metabolic tumor volume (MTV) and maximum standardized uptake value (SUVmax) of the primary tumor were measured. The associations between these metabolic parameters and histological type and differentiation were also evaluated. The differences in the accuracy in overall staging and T staging between PET-CT and contrast-enhanced CT were significant (91.1 vs. 69.6%, P=0.000; and 92.9 vs. 76.8%, P=0.000, respectively). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of regional lymph node metastasis detection were 91.7, 93.0, 86.5, 95.8 and 92.6%, respectively, with PET-CT; and 71.3, 77.2, 60.6, 84.5 and 75.2%, respectively, with contrast-enhanced CT. The SUVmax (7.29±1.83 vs. 5.91±1.65, t=4.15, P=0.000) and MTV (48.20±22.47 vs. 30.21±19.72 cm³, t=4.48, P=0.000) were significantly higher for squamous cell carcinoma (SCC) compared to those for adenocarcinoma (AC). There was a positive correlation between the MTV and SUVmax of the primary tumor (Pearson's r=0.838, P=0.000). Significant differences were observed among differentiation subgroups in the SUVmax and MTV of the primary tumor for both SCC and AC. In conclusion, compared to the postoperative pathological findings, the predictive value of ¹⁸F-FDG PET-CT for T and N staging in NSCLC was higher compared to that of contrast-enhanced CT. The FDG uptake of the primary tumor was associated with histological type and differentiation and the difference was statistically significant. Therefore, the SUVmax and MTV of the primary tumor may be valuable indices to partly predict the histological type and grade of differentiation of NSCLC.

Locoregional tumor failure after definitive radiation for patients with stage III non-small cell lung cancer

Background

Locoregional tumor failure (LRF) after definitive chemoradiation for patients with stage III NSCLC remains unacceptably high. This analysis sought to further define where LRF occurs relative to radiation dose received and pre-treatment PET scan-defined maximum standard uptake value (SUVmax).

Methods

This was a retrospective study analyzing patients with stage III NSCLC treated with definitive radiation between 2006 and 2011. LRF was defined as failure within the ipsilateral lung, hilum or mediastinum. The CT simulation scan with the radiation dose distribution was registered to the CT or PET/CT documenting LRF. The region of LRF was contoured, and the dose to 95% of the volume (D95) of LRF was extracted. The pre-treatment SUVmax was also extracted for the anatomic region of LRF.

Results

Sixty-one patients were identified. Median follow-up time was 19.1 months (range 2.37-76.33). Seventy four percent of patients were treated with 3-D conformal technique (3DCRT), 15% were treated with Intensity Modulated Radiotherapy (IMRT), and 11% were treated with a combination of 3DCRT and IMRT. Median prescribed radiation dose for all patients was 66 Gy (39.6-74). Concurrent chemotherapy was delivered in 90% of patients. Twenty-two patients (36%) developed a LRF, with a total of 39 anatomic regions of LRF identified. Median time to LRF was 11.4 months (3.5-44.6). Failures were distributed as follows: 36% were in-field failures, 27% were out-of-field failures, 18% were in-field and out-of-field failures, and 18% were in-field and marginal (recurrences within the field edge) failures. There were no isolated marginal failures. Of the patients that developed a LRF, 73% developed a LRF with an in-field component. Sixty-two percent of LRFs were nodal. The median pre-treatment SUVmax for the anatomic region of LRF for patients with an in-field failure was 13. The median D95 of in-field LRF was 63 Gy.

Conclusions

LRF after definitive chemoradiation are comprised primarily of in-field failures, though out-of field failures are not insignificant. Marginal failures are rare, indicating field margins are appropriate. Although radiation dose escalation to standard radiation fields has not yielded success, using PET parameters to define high-risk regions remains worthy of further investigation.

Roles of Ki-67, p53, transforming growth factor-β and lysyl oxidase in the metastasis of lung cancer

BACKGROUND AND OBJECTIVE

Most lung cancer (LC) patients have metastatic disease at time of diagnosis, which influence the treatment regimen and is the most important prognostic factor. The main purpose of our study was to evaluate the relationship between cell proliferation (Ki-67 label index), p53, transforming growth factor-β (TGF-β) and lysyl oxidase (LOX), and the metastatic stages of different lung cancers. The secondary aim was to correlate these parameters with the standardized uptake value (SUVmax) of the primary lesion during positron emission tomography-computed tomography (PET-CT).

METHODS

Eighty-five treatment-naive patients with LC were enrolled. All patients were examined with PET-CT. Ki-67, p53, TGF-β and LOX were evaluated histopathologically.

RESULTS

Small cell lung cancer (SCLC) showed the most intense staining in all parameters. A well-differentiated adenocarcinoma (AC) demonstrated a more diffuse and intense staining than squamous cell carcinoma (SCC). There was no statistically significant relationship between the four parameters and metastases of SCLC and SCC. However, a significant relationship between TGF-β, LOX and metastatic AC was demonstrated with regards to diffusivity and intensity. p53 and Ki-67 did not show a significant relationship. No correlation between SCLC and SCC and SUVmax was found. However, in AC, the diffusivity and intensity of the LOX and p53 staining showed a statistically significant relationship to the SUVmax.

CONCLUSIONS

LOX and TGF-β may play roles in metastatic AC. LOX and TGF-β may become markers of metastatic disease and inhibition could be explored for treatment.

Modern diagnostic and therapeutic interventional radiology in lung cancer

Imaging has an important role in the multidisciplinary management of primary lung cancer. This article reviews the current state-of-the-art imaging modalities used for the evaluation, staging and post-treatment follow-up and surveillance of lung cancers, and image-guided percutaneous techniques for biopsy to confirm the diagnosis and for local therapy in non-surgical candidates.

Positron emission tomography/computerized tomography in lung cancer

Positron emission tomography (PET) using 2-(18F)-flouro-2-deoxy-D-glucose (FDG) has emerged as a useful tool in the clinical work-up of lung cancer. This review article provides an overview of applications of PET in diagnosis, staging, treatment response evaluation, radiotherapy planning, recurrence assessment and prognostication of lung cancer.

New CT criteria for nodal staging in non-small cell lung cancer

OBJECTIVE

The purpose of our study was to develop a simple noninvasive technique for nodal staging using routine preoperative computed tomography (CT).

MATERIALS AND METHODS

The institutional review board approved this retrospective study, and written informed consent to perform the initial and follow-up CT studies was obtained from all patients. Preoperative CT findings (n=218 patients with resectable non-small cell lung cancer) and pathological diagnoses after surgical resection were evaluated. Using CT images, lymph node section area, circumference, and lesion attenuation values (LAVs) were drawn freehand, and the short axis (SA) and long axis (LA) were measured using caliper software. Receiver operating characteristic (ROC) curves were then used to analyze the section area, circumference, and LAVs.

RESULTS

Based on ROC curves, two cut-off values, lymph node section area >30 mm(2) and circumference >25 mm, showed greater sensitivity for nodal staging than the conventional criterion of lymph node SA ≥10 mm or the LA, SA/LA ratio or LAVs. Using lymph node section area >30 mm(2) for diagnosis, the sensitivity, specificity, and accuracy of nodal staging were 90.5%, 56.3%, and 58.3%, respectively. Using lymph node circumference >25 mm, the values were 76.2%, 70.4%, and 70.8%, respectively.

CONCLUSION

Lymph node section area >30 mm(2) and circumference >25 mm can serve as supportive criteria used by radiologists and surgeons to determine nodal staging. If these CT criteria are met, use of a more sensitive procedure such as positron emission tomography or mediastinoscopy is recommended.

CONCISE ABSTRACT

CT is used routinely during preoperative management of lung cancer. Based on ROC analyses, the cut-off values for surface area, circumference, the SA/LA ratio, and LAVs for diagnosis of lymph node metastasis were 30 mm(2), 25 mm, 0.65, and 50 Hounsfield units, respectively. Our findings indicate that lymph node surface area >30 mm(2) and circumference >25 mm are supportive criteria that can be used by radiologists and thoracic surgeons to determine nodal staging and surgical indications.

Positron emission tomography: clinical applications in oncology. Part 1

Positron emission tomography is a functional diagnostic imaging technique, which can accurately measure in vivo distribution of a radiopharmaceutical with high resolution. The ability of positron emission tomography to study various biologic processes opens up new possibilities for both research and day-to-day clinical use. Positron emission tomography has progressed rapidly from being a research technique in laboratories to a routine clinical imaging modality becoming part of armamentarium for the medical profession. The most widely used radiotracer in positron emission tomography is 18F-fluoro-2-deoxy-D-glucose (FDG), which is an analog of glucose. FDG uptake in cells is directly proportional to glucose metabolism of cells. Since glucose metabolism is increased many fold in malignant tumors, positron emission tomography has a high sensitivity and high negative predictive value. Positron emission tomography with FDG is now the standard of care in initial staging, monitoring the response to therapy and management of lung cancer, colorectal cancer, lymphoma, melanoma, esophageal cancer, head and neck cancer and breast cancer. The aim of this article is to review the clinical applications of positron emission tomography in oncology.

Lobe-specific mediastinal nodal dissection is sufficient during lobectomy by video-assisted thoracic surgery or thoracotomy for early-stage lung cancer

BACKGROUND

Lobectomy with complete mediastinal lymphadenectomy is considered standard for patients with early-stage non-small cell lung cancer (NSCLC). However, the benefits of complete lymphadenectomy are unproven. There is evidence suggesting a predictable pattern of mediastinal nodal drainage. This study analyzed the frequency and pattern of mediastinal nodal disease and its impact on outcome in patients with early-stage NSCLC.

METHODS

Patients with clinical N0/N1 NSCLC staged with CT scans and PET scans were identified. Disease involvement of resected nodal stations was recorded. Patterns of recurrence in patients who underwent lobectomy with complete mediastinal systematic lymph node sampling (SLNS) were compared with those who underwent lobe-specific mediastinal SLNS.

RESULTS

From July 2004 to April 2011, 370 patients were identified. Complete SLNS was performed in 282 patients. Fifteen patients (5.3%) in the group with complete SLNS were found to have N2 disease after pathologic evaluation. Patients with left-sided tumors were more likely to have pathologic N2 disease than were patients with right-sided tumors (P = .03). Only one patient (0.36%) had positive N2 disease in the distal mediastinum while skipping lobe-specific mediastinal nodes. In addition, patients with complete SLNS had a rate of recurrence similar to that of the group that had lobe-specific mediastinal evaluation (20.6% vs 18.2%, P = .68).

CONCLUSIONS

Mediastinal N2 metastases follow predictable lobe-specific patterns in patients with negative preoperative CT scans and PET scans. Lobe-specific N2 nodal evaluation results in a recurrence rate similar to that of complete mediastinal evaluation. Lobe-specific mediastinal nodal evaluation appears acceptable in patients with early-stage NSCLC.

Integrated positron emission tomography and computed tomography in preoperative lymph node staging of non-small cell lung cancer

BACKGROUND

Integrated positron emission tomography and computed tomography (PET/CT) is increasingly used for the preoperative nodal staging of non-small cell lung cancer (NSCLC). The aim of this study was to evaluate the accuracy of PET/CT in comparison with CT in detection of nodal metastasis and preoperative nodal staging in patients with NSCLC, and to analyze the causes of the PET/CT false-negative and false-positive results.

METHODS

Consecutive patients with pathologically proven NSCLC who underwent staging using PET/CT from July 2008 to February 2012 were evaluated retrospectively. Nodal staging was pathologically confirmed on tissue specimens obtained at thoracotomy. The accuracy of PET/CT and CT in the assessment of intrathoracic nodal involvement was determined using histological results as the reference standard. Logistic regression was used to define the causes of the false-negative and false-positive results.

RESULTS

A total of 528 lymph node stations were evaluated in 101 patients. Lymph nodes were positive for malignancy in 43 out of 101 patients (42.6%), and 101 out of 528 nodal stations (19.2%). PET/CT was significantly more accurate for nodal staging than CT. The sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT for detecting nodal metastasis were 51.5%, 95.8%, 74.3%, 89.3%, and 87.3% and the corresponding data by CT were 45.5%, 87.1%, 45.5%, 87.1%, and 79.2%, respectively. PET/CT confers significantly higher specificity, positive predictive value, and accuracy than CT in detecting nodal metastasis. False-negative results by PET/CT are significantly associated with smaller lymph node size, whereas false-positive results are related to a combination of inflammatory disorders and larger lymph node size.

CONCLUSION

PET/CT confers significantly higher accuracy than CT in nodal staging, and is more specific and accurate than CT in detecting nodal metastasis but has a low sensitivity and high false-negative rate.

Functional imaging in lung cancer

Lung cancer represents an increasingly frequent cancer diagnosis worldwide. An increasing awareness on smoking cessation as an important mean to reduce lung cancer incidence and mortality, an increasing number of therapy options and a steady focus on early diagnosis and adequate staging have resulted in a modestly improved survival. For early diagnosis and precise staging, imaging, especially positron emission tomography combined with CT (PET/CT), plays an important role. Other functional imaging modalities such as dynamic contrast-enhanced CT (DCE-CT) and diffusion-weighted MR imaging (DW-MRI) have demonstrated promising results within this field. The purpose of this review is to provide the reader with a brief and balanced introduction to these three functional imaging modalities and their current or potential application in the care of patients with lung cancer.

Mediastinoscopy: trends and practice patterns in the United States

OBJECTIVES

Historically, mediastinoscopy has been the gold standard for the staging of lung cancer. A practice gap exists as the result of a variation in knowledge concerning current trends and practice patterns of mediastinoscopy usage. In addition, there are regional variations in practice-based learning and patient care. Lessons learned during surgeries performed on patients with lung cancer and other advances such as positron emission tomography and endobronchial ultrasound could be universally applied to improve surgeons' management of patient care. The purpose of this study was to assess contemporary practices in the staging of lung cancer.

METHODS

We queried the Society of Thoracic Surgeons National Database for data regarding mediastinoscopy usage, yield, and variation, both by year and region.

RESULTS

Cases with mediastinoscopy, as a percentage of all cases performed in the database, have significantly decreased from 14.6% in 2006 to 11.4% in 2010 (P < 0.001). The 5-year median rate of mediastinoscopy in lung cancer patients at 163 centers was 15.3% (interquartile range 5.2%-31.7%), indicating significant variation among centers. The overall median center rate also decreased over time from 21.4% (2006) to 10.0% (2010).

CONCLUSIONS

With advances in minimally invasive procedures and imaging, mediastinoscopy usage has declined significantly. Our findings are likely to be relevant to both clinical practice and practice guidelines.

Characteristics of Metastatic Mediastinal Lymph Nodes of Non-Small Cell Lung Cancer on Preoperative F-18 FDG PET/CT

PURPOSE

The aim of this study was to evaluate the characteristics of PET and CT features of mediastinal metastatic lymph nodes on F-18 FDG PET/CT and to determine the diagnostic criteria in nodal staging of non-small cell lung cancer.

METHODS

One hundred four non-small cell lung cancer patients who had preoperative F-18 FDG PET/CT were included. For quantitative analysis, the maximum SUV of the primary tumor, maximum SUV of the lymph nodes (SUVmax), size of the lymph nodes, and average Hounsfield units (aHUs) and maximum Hounsfield units (mHUs) of the lymph nodes were measured. The SUVmax, SUV ratio of the lymph node to blood pool (LN SUV/blood pool SUV), SUV ratio of the lymph node to primary tumor (LN SUV/primary tumor SUV), size, aHU, and mHU were compared between the benign and malignant lymph nodes.

RESULTS

Among 372 dissected lymph node stations that were pathologically diagnosed after surgery, 49 node stations were malignant and 323 node stations benign. SUVmax, LN SUV/blood pool SUV, and size were significantly different between the malignant and benign lymph node stations (P < 0.0001). However, there was no significant difference in LN SUV/primary tumor SUV (P = 0.18), mHU (P = 0.42), and aHU (P = 0.98). Using receiver-operating characteristic curve analyses, there was no significant difference among these three variables (SUVmax, LN SUV/blood pool SUV, and size). The optimal cutoff values were 2.9 for SUVmax, 1.4 for LN SUV/blood pool SUV, and 5 mm for size. When the cutoff value of SUVmax ≥2.9 and size ≥5 mm were used in combination, the positive predictive value was 44.2 %, and the negative predictive value was 90.9 %. When we evaluated the results based on the histology of the primary tumor, the negative predictive value was 92.3 % in adenocarcinoma (cutoff values of SUVmax ≥2.3 and size ≥5 mm) and 97.2 % in squamous cell carcinoma (cutoff values of SUVmax ≥3.6 and size ≥8 mm), separately.

CONCLUSIONS

In the lymph node staging of non-small cell lung cancer, SUVmax, LN SUV/blood pool SUV, and size show statistically significant differences between malignant and benign lymph nodes. These variables can be used to differentiate malignant from benign lymph nodes. The combination of the SUVmax and size of lymph node might have a good negative predictive value.

Reproducibility of the adaptive thresholding calibration procedure for the delineation of 18F-FDG-PET-positive lesions

OBJECTIVE

The aim of the study was to evaluate the robustness of the calibration procedure against the counting statistics and lesion volumes when using an adaptive thresholding method for the delineation of 2-[18F]fluoro-2-deoxyglucose (18F-FDG)-PET-positive tissue.

MATERIALS AND METHODS

Three data sets obtained from physical and simulated images of a phantom containing hot spheres of known volume and contrast were used to study the robustness of the calibration procedure against the counting statistics and range of volumes and contrasts for a given PET model. The mathematical expression of the adaptive thresholding method used corresponds to a linear relationship between the optimal threshold value and the inverse of the local contrast. Robustness was evaluated by testing whether the slopes and intercepts of the linear expression found under two experimental conditions were significantly different (P<0.05).

RESULTS

It was found that the calibration step was not sensitive to the PET device for the studied PET model, nor to the counting statistics for a signal-to-noise ratio higher than 5.7. No statistical difference was found in the calibration step when using a wide range of volumes (0.2-200 ml) and contrasts (2.0-20.6) or more restricted ones (0.43-97.3 ml and 2.0-7.7, respectively). Therefore, a calibration procedure using limited experimental conditions can be applied to a wider range of volumes and contrasts.

CONCLUSION

These results show that the manufacturer could propose simulated or experimental raw data corresponding to a given PET model with high counting statistics, allowing each clinical center to reconstruct calibration images according to the algorithm parameters used in the clinic.

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.

Are discordant positron emission tomography and pathological assessments of the mediastinum in non-small cell lung cancer significant?

OBJECTIVE

Many patients with non-small cell lung cancer have positive mediastinal lymph nodes on preoperative positron emission tomography (PET) but do not have mediastinal involvement after surgery. The prognostic significance of this discordance was assessed.

METHODS

This Institutional Review Board-approved study evaluated patients treated with upfront surgery at Duke Cancer Institute (Durham, NC) for non-small cell lung cancer from 1995 to 2008. Those staged with PET with pN0-1 disease after negative invasive mediastinal assessment were included. Mediastinal lymph nodes were scored as positive or negative based on visual analysis of the preoperative PET. Clinical outcomes of the PET-positive and PET-negative cohorts were estimated using the Kaplan-Meier method and compared using a log-rank test. Prognostic factors were assessed using a multivariate analysis.

RESULTS

A total of 547 patients were assessed, of whom 105 (19%) were PET positive in the mediastinum. The median number of mediastinal lymph node stations sampled was 4 (range, 1-9). The 5-year risk of local recurrence was 26% in PET-positive versus 21% in PET-negative patients (P = .50). Patterns of local failure were similar between the 2 groups. Distant recurrence (35% vs 29%; P = .63) and overall survival (44% vs 54%; P = .52) were comparable for PET-positive and PET-negative patients. On multivariate analysis, a positive PET was not significant for local recurrence (hazard ratio [HR], 1; P = 1), distant recurrence (HR, 0.82; P = .42), or overall survival (HR, 1.08; P = .62).

CONCLUSIONS

Patients with positive mediastinal lymph nodes on preoperative PET, but negative on histologic analysis, are not at increased risk of disease recurrence. Pathologic staging remains the standard.

Diagnostic imaging in the preoperative management of lung cancer

Surgical resection is the accepted standard of care for patients with non-small cell lung cancer (NSCLC). Several imaging modalities play central roles in the detection and staging of the disease. The aim of this review is to evaluate the utility of computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and PET/CT for NSCLC staging. Radiographic staging refers to the use of CT as a non-invasive diagnostic technique. However, while the vast majority of patients undergo only CT, CT is a notoriously inaccurate means of tumor and nodal staging in many situations. PET/CT clearly improves the staging, particularly nodal staging, compared to CT or PET alone. In addition, as a result of the increased soft-tissue contrast, MRI is superior to CT for distinguishing between tissue characteristics. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), which is a minimally invasive technique, also has pathological diagnostic potential. Extensive research and the resultant improvements in the understanding of genetics, histology, molecular biology and oncology are transforming our understanding of lung cancer, and it is clear that imaging modalities such as CT, MRI, PET and PET/CT will have an important role in its preoperative management. However, thoracic surgeons should also be aware of the limitations of these techniques.

A practical algorithmic approach to the diagnosis and management of solitary pulmonary nodules: part 1: radiologic characteristics and imaging modalities

The solitary pulmonary nodule (SPN) is frequently encountered on chest imaging and poses an important diagnostic challenge to clinicians. The differential diagnosis is broad, ranging from benign granulomata and infectious processes to malignancy. Important concepts in the evaluation of SPNs include the definition, morphologic characteristics via appropriate imaging modalities, and the calculation of pretest probability of malignancy. Morphologic differentiation of SPN into solid or subsolid types is important in the choice of follow-up and further management. In this first part of a two-part series, we describe the morphologic characteristics and various imaging modalities available to further characterize SPN. In Part 2, we will describe the determination of pretest probability of malignancy and an algorithmic approach to the diagnosis of SPN.

Positron emission tomography-computed tomography in the management of lung cancer: An update

This communication presents an update on the current role of positron emission tomography-computed tomography (PET-CT) in the various clinical decision-making steps in lung carcinoma. The modality has been reported to be useful in characterizing solitary pulmonary nodules, improving lung cancer staging, especially for the detection of nodal and metastatic site involvement, guiding therapy, monitoring treatment response, and predicting outcome in non-small cell lung carcinoma (NSCLC). Its role has been more extensively evaluated in NSCLC than small cell lung carcinoma (SCLC). Limitations in FDG PET-CT are encountered in cases of tumor histotypes characterized by low glucose uptake (mucinous forms, bronchioalveolar carcinoma, neuroendocrine tumors), in the assessment of brain metastases (high physiologic 18F-FDG uptake in the brain) and in cases presenting with associated inflammation. The future potentials of newer PET tracers beyond FDG are enumerated. An evolving area is PET-guided assessment of targeted therapy (e.g., EGFR and EGFR tyrosine kinase overexpression) in tumors which have significant potential for drug development.

Imaging features of extrapulmonary small cell carcinoma

Small cell carcinoma accounts for approximately 20% of lung cancers; however, it rarely occurs at other sites. Extrapulmonary small cell carcinoma (EPSCC) is notoriously aggressive with a strong propensity for both regional and distant spread. The majority of the literature on these uncommon tumours is from a clinicopathological viewpoint with a relative paucity of detail regarding the radiological findings. This review will focus on the imaging features of EPSCC in its predominant sites of origin: the gastrointestinal tract, genitourinary tract, head, neck, and breast. We will also discuss the role of positron-emission tomography (PET)/computed tomography (CT) in the staging of EPSCC.

'Go with the flow ': a review of methods and advancements in blood flow imaging

Physics has delivered extraordinary developments in almost every facet of modern life. From the humble thermometer and stethoscope to X-Ray, CT, MRI, ultrasound, PET and radiotherapy, our health has been transformed by these advances yielding both morphological and functional metrics. Recently high resolution label-free imaging of the microcirculation at clinically relevant depths has become available in the research domain. In this paper, we present a comprehensive review on current imaging techniques, state-of-the-art advancements and applications, and general perspectives on the prospects for these modalities in the clinical realm.

Guidelines for the role of FDG-PET/CT in lung cancer management

Fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography (PET) and PET/computed tomography (FDG-PET/CT) is regarded as a standard of care in the management of non-small-cell lung carcinoma (NSCLC) and is a useful adjunct in the characterization of indeterminate solitary lung nodules (SLN), and pre-treatment staging of NSCLC, notably mediastinal nodal staging and detection of remote metastases. FDG-PET/CT has the ability to assess locoregional lymph node spread more precisely than CT, to detect metastatic lesions that would have been missed on conventional imaging or are located in difficult areas, and to help in the differentiation of lesions that are equivocal after conventional imaging. Increasingly FDG-PET/CT is employed in radiotherapy planning, prediction of prognosis in terms of tumor response to neo-adjuvant, radiation and chemotherapy treatment. Evidence is accumulating of usefulness of PET/CT in small cell lung cancer.

Mediastinal lymph node staging: from noninvasive to surgical

OBJECTIVE

The purpose of this review is to describe the current lymph node stations and lymph node staging of non-small cell lung carcinoma. Minimally invasive and invasive methods of mediastinal lymph node staging are emphasized, and the relative accuracy and limitations of each modality are described.

CONCLUSION

Lung carcinoma remains the most common cause of cancer death in the United States. Accurate staging of lung cancer is imperative for implementing the correct therapy and assessing patient prognosis.