Can chest CT decrease the use of preoperative bronchoscopy in the evaluation of suspected bronchogenic carcinoma?

A Novel Translational Ovine Pulmonary Adenocarcinoma Model for Human Lung Cancer

In vitro cell line and in vivo murine models have historically dominated pre-clinical cancer research. These models can be expensive and time consuming and lead to only a small percentage of anti-cancer drugs gaining a license for human use. Large animal models that reflect human disease have high translational value; these can be used to overcome current pre-clinical research limitations through the integration of drug development techniques with surgical procedures and anesthetic protocols, along with emerging fields such as implantable medical devices. Ovine pulmonary adenocarcinoma (OPA) is a naturally-occurring lung cancer that is caused by the jaagsiekte sheep retrovirus. The disease has similar histological classification and oncogenic pathway activation to that of human lung adenocarcinomas making it a valuable model for studying human lung cancer. Developing OPA models to include techniques used in the treatment of human lung cancer would enhance its translational potential, making it an excellent research tool in assessing cancer therapeutics. In this study we developed a novel OPA model to validate the ability of miniaturized implantable O₂ and pH sensors to monitor the tumor microenvironment. Naturally-occurring pre-clinical OPA cases were obtained through an on-farm ultrasound screening programme. Sensors were implanted into OPA tumors of anesthetized sheep using a CT-guided trans-thoracic percutaneous implantation procedure. This study reports the findings from 9 sheep that received sensor implantations. Time taken from initial CT scans to the placement of a single sensor into an OPA tumor was 45 ± 5 min, with all implantations resulting in the successful delivery of sensors into tumors. Immediate post-implantation mild pneumothoraces occurred in 4 sheep, which was successfully managed in all cases. This is, to the best of our knowledge, the first description of the use of naturally-occurring OPA cases as a pre-clinical surgical model. Through the integration of techniques used in the treatment of human lung cancer patients, including ultrasound, general anesthesia, CT and surgery into the OPA model, we have demonstrated its translational potential. Although our research was tailored specifically for the implantation of sensors into lung tumors, we believe the model could also be developed for other pre-clinical applications.

Outcome of incidentally detected airway nodules

Low-dose chest computed tomography (LDCT) screening increased detection of airway nodules. Most nodules appear to be secretions, but pathological lesions may show similar findings. The National Comprehensive Cancer Network (NCCN) recommends repeating LDCT after 1 month and proceeding to bronchoscopy if the nodules persist. However, no reports exist about incidentally detected airway nodules. We investigated the significance of airway nodules detected by LDCT screening.We screened patients with incidental airway nodules detected by LDCT in the Seoul National University Hospital group. The characteristics of computed tomography, bronchoscopy, pathology and clinical findings were analysed.Among 53 036 individuals who underwent LDCT screening, 313 (0.6%) had airway nodules. Of these, 186 (59.4%) were followed-up with chest computed tomography and/or bronchoscopy. Seven (3.8%) cases had significant lesions, including leiomyoma (n=2), endobronchial tuberculosis (n=2), chronic inflammation (n=1), hamartoma (n=1) and benign granuloma (n=1). The remaining 179 lesions were transient, suggesting that they were secretions.The use of LDCT for lung cancer screening demonstrated the low incidence of airway lesions. Most lesions were transient secretions. True pathological lesions were rare, and no malignant lesion was found. The current recommendation of the NCCN guideline is a reasonable approach that can avoid unnecessary bronchoscopy.

[Incidental bronchoscopic findings]

Inflexible and flexible bronchoscopy represents a standard diagnostic procedure in pneumology. Besides lung carcinomas, which is the most frequent indication for diagnostic bronchoscopy, a plethora of clinical symptoms such as chronic persistent cough, hoarseness, unexplained dyspnea, hemoptysis, and suspicious findings on auscultation require further endoscopic evaluation. Moreover, bronchoscopy plays a central role in the diagnostic work-up of interstitial lung diseases and persistent lung infiltrates, in particular those of infectious origin (e.g., fungal, viral, tuberculous, and Pneumocystis jiroveci infections). In addition, diagnostic bronchoscopy has more recently been complemented by endobronchial ultrasound (EBUS). EBUS is predominantly employed for the accurate diagnosis and mediastinal staging of lung carcinomas, and the assessment of lympadenopathy-associated diseases such as sarcoidosis.Since endoscopic evaluation is typically preceded by computed tomography (CT) of the chest, genuine incidental findings occur relatively seldom and usually account for pathological findings that have been missed on conventional imaging approaches. For instance, characteristic incidental findings include benign and malignant tumors in the area of the endoscopic access and central airways, anatomical variations and (vascular) malformations, tracheal and bronchial airway alterations, and aspirated objects. This review focuses on bronchoscopic findings that have either been completely missed by conventional imaging or differently interpreted due to its radiologic morphology.

Diagnostic yield of non-guided flexible bronchoscopy for peripheral pulmonary neoplasia

Background

The role of conventional bronchoscopy for peripheral pulmonary neoplasia remains controversial. We aimed to assess the diagnostic yield and the added value of non-guided bronchial aspiration, bronchoalveolar lavage (BAL), and brushing for the diagnosis of pulmonary neoplasia not visible endoscopically.

Methods

We retrospectively assessed 207 consecutive patients with a final diagnosis of peripheral lung malignancy who underwent bronchoscopy with non-guided aspiration, brushing, and BAL as their initial evaluation. The influence of clinical and radiological factors on diagnostic yield was assessed using univariate logistic regression analyses.

Results

The overall sensitivity of non-guided bronchoscopy was 25.6%, whereas sensitivities for bronchial aspiration, BAL, and brushing were 14.2%, 11.6%, and 16.5%, respectively. Younger age, larger lesion, central/intermediate distance from the hilum, presence of a bronchus sign, and higher standardized uptake value (SUV) on positron emission tomography scan were predictors of a higher diagnostic yield. Conversely, forced expiratory volume in one second, fellow implication in the procedure, and tumor histology did not influence sensitivity. The overall sensitivity of bronshoscopy was >40% for tumors >4 cm, located in the central/intermediate thirds of the lung, showing a bronchus sign, with an SUV >12 or occurring in patients <50 years of age. Conversely, the sensitivity was <10% for tumors <2 cm, located peripherally or with an SUV <4.

Conclusion

Neoplasia characteristics may help targeting situations in which conventional bronchoscopy could be used as the initial diagnostic procedure when advanced techniques are unavailable. However, advanced diagnostic tools should probably be proposed as the initial modality for the diagnosis of peripheral malignant lesions when available.

Establishing the diagnosis of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Lung cancer is usually suspected in individuals who have an abnormal chest radiograph or have symptoms caused by either local or systemic effects of the tumor. The method of diagnosis of lung cancer depends on the type of lung cancer (small cell lung cancer or non-small cell lung cancer [NSCLC]), the size and location of the primary tumor, the presence of metastasis, and the overall clinical status of the patient. The objective of this study was to determine the test performance characteristics of various modalities for the diagnosis of suspected lung cancer.

METHODS

To update previous recommendations on techniques available for the initial diagnosis of lung cancer, a systematic search of the MEDLINE, Healthstar, and Cochrane Library databases covering material to July 2011 and print bibliographies was performed to identify studies comparing the results of sputum cytology, conventional bronchoscopy, flexible bronchoscopy (FB), electromagnetic navigation (EMN) bronchoscopy, radial endobronchial ultrasound (R-EBUS)-guided lung biopsy, transthoracic needle aspiration (TTNA) or biopsy, pleural fluid cytology, and pleural biopsy with histologic reference standard diagnoses among at least 50 patients with suspected lung cancer. Recommendations were developed by the writing committee, graded by a standardized method (see the article "Methodology for Development of Guidelines for Lung Cancer" in this guideline), and reviewed by all members of the Lung Cancer Guideline Panel prior to approval by the Thoracic Oncology NetWork, the Guidelines Oversight Committee, and the Board of Regents of the American College of Chest Physicians.

RESULTS

Sputum cytology is an acceptable method of establishing the diagnosis of lung cancer, with a pooled sensitivity rate of 66% and a specificity rate of 99%. However, the sensitivity of sputum cytology varies according to the location of the lung cancer. For central, endobronchial lesions, the overall sensitivity of FB for diagnosing lung cancer is 88%. The diagnostic yield of bronchoscopy decreases for peripheral lesions. Peripheral lesions &lt; 2 or &gt; 2 cm in diameter showed a sensitivity of 34% and 63%, respectively. R-EBUS and EMN are emerging technologies for the diagnosis of peripheral lung cancer, with diagnostic yields of 73% and 71%, respectively. The pooled sensitivity of TTNA for the diagnosis of lung cancer was 90%. A trend toward lower sensitivity was noted for lesions &lt; 2 cm in diameter. TTNA is associated with a higher rate of pneumothorax compared with bronchoscopic procedures. In a patient with a malignant pleural effusion, pleural fluid cytology is reported to have a mean sensitivity of about 72%. A definitive diagnosis of metastatic disease to the pleural space can be estalished with a pleural biopsy. The diagnostic yield for closed pleural biopsy ranges from 38% to 47% and from 75% to 88% for image-guided closed biopsy. Thoracoscopic biopsy of the pleura carries the highest diagnostic yield, 95% to 97%. The accuracy in differentiating between small cell and non-small cell cytology for the various diagnostic modalities was 98%, with individual studies ranging from 94% to 100%. The average false-positive and false-negative rates were 9% and 2%, respectively. Although the distinction between small cell and NSCLC by cytology appears to be accurate, NSCLCs are clinically, pathologically, and molecularly heterogeneous tumors. In the past decade, clinical trials have shown us that NSCLCs respond to different therapeutic agents based on histologic phenotypes and molecular characteristics. The physician performing diagnostic procedures on a patient suspected of having lung cancer must ensure that adequate tissue is acquired to perform accurate histologic and molecular characterization of NSCLCs.

CONCLUSIONS

The sensitivity of bronchoscopy is high for endobronchial disease and poor for peripheral lesions &lt; 2 cm in diameter. The sensitivity of TTNA is excellent for malignant disease, but TTNA has a higher rate of pneumothorax than do bronchoscopic modalities. R-EBUS and EMN bronchoscopy show potential for increasing the diagnostic yield of FB for peripheral lung cancers. Thoracoscopic biopsy of the pleura has the highest diagnostic yield for diagnosis of metastatic pleural effusion in a patient with lung cancer. Adequate tissue acquisition for histologic and molecular characterization of NSCLCs is paramount.

Newer modalities in the work-up of peripheral pulmonary nodules

Technological advances in recent years have translated into the availability of newer modalities to establish the cause of peripheral pulmonary nodules (PPN). Even though the verdict is still out on the ideal diagnostic modality, there is no doubt that the bronchoscope is becoming a popular tool in the armamentarium of physicians who deal with PPN. This article focuses on newer bronchoscopic modalities being studied for the work-up of PPN. The authors also summarize the value of established diagnostic modalities to provide a balanced perspective.

Endobronchial tumours in a campaign for early detection of bronchial cancer: Computed tomography versus endoscopy

OBJECTIVE

To study endobronchial cancers occurring in a population at high risk of bronchial cancer (history of surgically treated bronchial or ENT cancer in complete remission, and symptoms due to smoking) detected by annual volume CT scans and biannual fibroscopy.

MATERIAL AND METHODS

Two hundred and sixty-six patients were included in this single centre prospective study; 27 bronchopulmonary cancers were detected. Ten endobronchial cancers (37%) were identified by fibroscopy (nine invasive cancers and one carcinoma in situ) in 10 patients (nine men) (51-78 years old) nine of whom were smokers (dark tobacco: seven). The screening CTs were reappraised by two radiologists.

RESULTS

Three cancers out of 10 were detected by CT during the initial reading. The sensitivity of the reappraised CT was 80% with seven false positives. In five cases, the mean period between the first CT scan where the lesion was visible retrospectively, but not described, and the diagnostic fibroscopy was 463 days (213-808 days); two cancers were not visible in the CT scan. Seven curative treatments were undertaken.

CONCLUSION

In this population, the sensitivity of the initial reading of the CT scan for detecting endobronchial tumours was 30%, while 80% of the tumours were visible retrospectively, underlining the importance of careful analysis of the proximal bronchial tree.

Predictors of diagnostic yield in bronchoscopy: a retrospective cohort study comparing different combinations of sampling techniques

BACKGROUND

The reported diagnostic yield from bronchoscopies in patients with lung cancer varies greatly. The optimal combination of sampling techniques has not been finally established. The objectives of this study were to find the predictors of diagnostic yield in bronchoscopy and to evaluate different combinations of sampling techniques.

METHODS

All bronchoscopies performed on suspicion of lung malignancy in 2003 and 2004 were reviewed, and 363 patients with proven malignant lung disease were included in the study. Sampling techniques performed were biopsy, transbronchial needle aspiration (TBNA), brushing, small volume lavage (SVL), and aspiration of fluid from the entire procedure. Logistic regression analyses were adjusted for sex, age, endobronchial visibility, localization (lobe), distance from carina, and tumor size.

RESULTS

The adjusted odds ratios (OR) with 95% confidence intervals (CI) for a positive diagnostic yield through all procedures were 17.0 (8.5-34.0) for endobronchial lesions, and 2.6 (1.3-5.2) for constriction/compression, compared to non-visible lesions; 3.8 (1.3-10.7) for lesions > 4 cm, 6.7 (2.1-21.8) for lesions 3-4 cm, and 2.5 (0.8-7.9) for lesions 2-3 cm compared with lesions <= 2 cm. The combined diagnostic yield of biopsy and TBNA was 83.7% for endobronchial lesions and 54.2% for the combined group without visible lesions. This was superior to either technique alone, whereas additional brushing, SVL, and aspiration did not significantly increase the diagnostic yield.

CONCLUSION

In patients with malignant lung disease, visible lesions and larger tumor size were significant predictors of higher diagnostic yield, after adjustment for sex, age, distance from carina, side and lobe. The combined diagnostic yield of biopsy and TBNA was significant higher than with either technique alone.

Initial Diagnosis of Lung Cancer

BACKGROUND

Lung cancer is usually suspected in individuals who have an abnormal chest radiograph finding or have symptoms caused by either local or systemic effects of the tumor. The method of diagnosis of suspected lung cancer depends on the type of lung cancer (ie, small cell lung cancer [SCLC] or non-SCLC [NSCLC]), the size and location of the primary tumor, the presence of metastasis, and the overall clinical status of the patient.

OBJECTIVES

To determine the test performance characteristics of various modalities for the diagnosis of suspected lung cancer.

METHODS

To update previous recommendations on the initial diagnosis of lung cancer, a systematic search of MEDLINE, Healthstar, and Cochrane Library databases to July 2004, and print bibliographies was performed to identify studies comparing the results of sputum cytology, bronchoscopy, transthoracic needle aspiration (TTNA), or biopsy with histologic reference standard diagnoses among at least 50 patients with suspected lung cancer. Recommendations were developed by the writing committee, graded by a standardized method, and reviewed by all members of the lung cancer panel prior to approval by the Thoracic Oncology Network, Health and Science Policy Committee, and the Board of Regents of the American College of Chest Physician.

RESULTS

Sputum cytology is an acceptable method of establishing the diagnosis of lung cancer with a pooled sensitivity rate of 0.66 and specificity rate of 0.99. However, the sensitivity of sputum cytology varies by location of the lung cancer. For central, endobronchial lesions, the overall sensitivity of flexible bronchoscopy (FB) for diagnosing lung cancer is 0.88. The diagnostic yield of bronchoscopy decreases for peripheral lesions. Peripheral lesions smaller or larger than 2 cm in diameter showed a sensitivity of 0.34 and 0.63, respectively. In recent years, endobronchial ultrasound (EBUS) has shown potential in increasing the diagnostic yield of FB while dealing with peripheral lesions without adding to the risk of the procedure. In appropriate situations, its use can be considered before moving on to more invasive tests. The pooled sensitivity for TTNA for the diagnosis of lung cancer is 0.90. A trend toward lower sensitivity was noted for lesions < 2 cm in diameter. The accuracy in differentiating between SCLC and NSCLC cytology for the various diagnostic modalities was 0.98, with individual studies ranging from 0.94 to 1.0. The average false-positive rate and FN rate were 0.09 and 0.02, respectively.

CONCLUSIONS

The sensitivity of bronchoscopy is high for the detection of endobronchial disease and poor for peripheral lesions < 2 cm in diameter. Detection of the latter can be aided with the use of EBUS in the appropriate clinical setting. The sensitivity of TTNA is excellent for malignant disease. The distinction between SCLC and NSCLC by cytology appears to be accurate.

Performance characteristics of different modalities for diagnosis of suspected lung cancer: summary of published evidence

STUDY OBJECTIVES

To determine the test performance characteristics of various modalities for the diagnosis of suspected lung cancer.

DESIGN, SETTING, AND PARTICIPANTS

A systematic search of MEDLINE, HealthStar, and Cochrane Library databases to July 2001 and print bibliographies was performed to identify studies comparing the results of sputum cytology, bronchoscopy, transthoracic needle aspirate (TTNA), or biopsy with histologic reference standard diagnoses among at least 50 patients with suspected lung cancer.

MEASUREMENT AND RESULTS

For sputum cytology, the pooled specificity was 0.99 and the pooled sensitivity was 0.66, but sensitivity was higher for central lesions than for peripheral lesions (0.71 vs 0.49, respectively). Studies on bronchoscopic procedures provided data only on diagnostic yield (sensitivity). The diagnosis of endobronchial disease by bronchoscopy in 30 studies showed the highest sensitivity for endobronchial biopsy (0.74), followed by cytobrushing (0.59) and washing (0.48). The sensitivity for all modalities combined was 0.88. Thirty studies reported on peripheral lesions. Cytobrushing demonstrated the highest sensitivity (0.52), followed by transbronchial biopsy (0.46) and BAL/washing (0.43). The overall sensitivity for all modalities was 0.69. Peripheral lesions < 2 cm or > 2 cm in diameter showed sensitivities of 0.33 and 0.62, respectively. Updating a previous meta-analysis with 19 studies revealed a pooled sensitivity of 0.90 for TTNA. A trend toward lower sensitivity was noted for lesions that were < 2 cm in diameter. The accuracy in differentiating between small cell and non-small cell cytology for the various diagnostic modalities was 0.98, with individual studies ranging from 0.94 to 1.0. The average false-positive and false-negative rates were 0.09 and 0.02, respectively.

CONCLUSIONS

The sensitivity of bronchoscopy is high for endobronchial disease and poor for peripheral lesions that are < 2 cm in diameter. The sensitivity of TTNA is excellent for malignant disease. The distinction between small cell lung cancer and non-small cell lung cancer by cytology appears to be accurate.

Percutaneous biopsy in lung cancer

This paper presents current indications, contraindications, technical aspects, complications and yield of diagnosis of percutaneous lung biopsy in the setting of lung cancer. Percutaneous lung biopsy should be performed each time that the therapeutic strategy can be significantly influenced, when the procedure is technically feasible and to patients for which the benefits outweigh the risks, that are pneumothorax and pulmonary haemorrhage. Factors identified as potentially favouring post-biopsy pneumothorax are numerous whereas the use of a needle size larger than 18 gauge is the major risk factor of bleeding. Although a coaxial system is highly suitable in any case, two categories of needles can be used; those providing aspiration and those for core biopsies. Both offer similar yields for the diagnosis of malignancy, but core biopsies are more efficient for the specific diagnosis of benignity and lymphoma. Technical improvements of guidance, needle design and pathological techniques may contribute to lower the size limit of the nodule to be biopsied, to decrease the complication rate and their severity and to increase the yield of diagnosis.

Estimation of performance and sequential selection of diagnostic tests in patients with lung lesions suspicious for cancer

CONTEXT

Measuring variation in clinician test ordering behavior for patients with similar indications is an important focus for quality management and cost containment.

OBJECTIVE

To obtain information from physicians and nonphysicians regarding their test-ordering behavior and their knowledge of test performance characteristics for diagnostic tests used to work up patients with lung lesions suspicious for cancer.

DESIGN

A self-administered, voluntary, anonymous questionnaire was distributed to 452 multiple-specialty physicians and 500 nonphysicians in academic and private practice in Pennsylvania, Iowa, and North Carolina. Respondents indicated their estimates of test sensitivities for multiple tests used in the diagnosis of lung lesions and provided their test selection strategy for case simulations of patients with solitary lung lesions. Data were analyzed using descriptive statistics and the chi(2) test.

RESULTS

The response rate was 11.2%. Both physicians and nonphysicians tended to underestimate the sensitivities of all minimally invasive tests, with the greatest underestimations reported for sputum cytology and transthoracic fine-needle aspiration biopsy. There was marked variation in sequential test selection for all the case simulations and no association between respondent perception of test sensitivity and their selection of first diagnostic test. Overall, the most frequently chosen first diagnostic test was bronchoscopy.

CONCLUSIONS

Physicians and nonphysicians tend to underestimate the performance of diagnostic tests used to evaluate solitary lung lesions. However, their misperceptions do not appear to explain the wide variation in test-ordering behavior for patients with lung lesions suspicious for cancer.

Intravenous extension of lung carcinoma to the left atrium: demonstration by positron emission tomography with CT correlation

Intravenous extension of lung carcinoma is rare. A right upper lobe bronchogenic carcinoma with unusually elongated intravenous extension to the left atrium was first visualized with positron emission tomography (PET) and then confirmed with dynamic CT. The PET appearance of intravascular tumour spread is striking, and presents only a short differential diagnosis.