Needle Biopsy Of Lung Research Articles

Multimodal Sparse Representation-Based Classification for Lung Needle Biopsy Images

Lung needle biopsy image classification is a critical task for computer-aided lung cancer diagnosis. In this study, a novel method, multimodal sparse representation-based classification (mSRC), is proposed for classifying lung needle biopsy images. In the data acquisition procedure of our method, the cell nuclei are automatically segmented from the images captured by needle biopsy specimens. Then, features of three modalities (shape, color, and texture) are extracted from the segmented cell nuclei. After this procedure, mSRC goes through a training phase and a testing phase. In the training phase, three discriminative subdictionaries corresponding to the shape, color, and texture information are jointly learned by a genetic algorithm guided multimodal dictionary learning approach. The dictionary learning aims to select the topmost discriminative samples and encourage large disagreement among different subdictionaries. In the testing phase, when a new image comes, a hierarchical fusion strategy is applied, which first predicts the labels of the cell nuclei by fusing three modalities, then predicts the label of the image by majority voting. Our method is evaluated on a real image set of 4372 cell nuclei regions segmented from 271 images. These cell nuclei regions can be divided into five classes: four cancerous classes (corresponding to four types of lung cancer) plus one normal class (no cancer). The results demonstrate that the multimodal information is important for lung needle biopsy image classification. Moreover, compared to several state-of-the-art methods (LapRLS, MCMI-AB, mcSVM, ESRC, KSRC), the proposed mSRC can achieve significant improvement (mean accuracy of 88.1%, precision of 85.2%, recall of 92.8%, etc.), especially for classifying different cancerous types.

Problemas clínicos en micología médica: problema número 46

A 49 year old-man, without known previous diseases, who suffered an acute lung infection, is presented. He was a smoker and belonged to a high socioeconomic class. He suddenly presented high fever, dry cough and legs’ pain. Thorax X-ray and CT scan showed two excavated pneumonic infiltrates in the lower part of the right lung. He was treated with antibacterial antibiotics without clinical response. A transparietal fine needle lung biopsy was performed and the histopathology and cytological studies revealed an epithelioid granuloma with capsulated yeasts. Cryptococcus neoformans antigenemia was positive 1/128, and brain MR, as well as CSF studies, allowed to rule out a central nervous system compromise. The patient was successfully treated with itraconazole by oral route at a daily dose of 400mg during 6 months. Post-treatment thorax CT scan showed a thin walled lung cavity as a sequela.

Diagnostic performance of percutaneous lung biopsy using automated biopsy needles under CT-fluoroscopic guidance for ground-glass opacity lesions

The goal of our study was to evaluate the diagnostic performance of percutaneous lung biopsy under CT-fluoroscopic guidance for ground-glass opacity (GGO) lesions. 85 percutaneous needle lung biopsies were performed in 73 patients. Specimens were obtained by core biopsy utilising an automated cutting needle and were evaluated histologically. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Rates of adequate specimens obtained and of precise diagnosis by needle biopsy were 92.9% (79/85) and 90.6% (77/85) of evaluated lung lesions, respectively. Precise diagnosis was achieved in 87.1% (27/31) of lesions ≤10 mm in diameter, 90.0% (36/40) of lesions >10 mm to ≤20 mm and 100.0% (14/14) of lesions >20 mm. Precision in diagnosing GGO lesions according to the GGO component was 73.9% (17/23) for pure GGO lesions and 96.8% (60/62) for part-solid GGO lesions. Obtaining a precise diagnosis did not differ significantly according to the lesion size (p=0.3840), but differences were significant according to the GGO component (p=0.0047). Malignancy was accurately diagnosed in 35 of 36 malignant lesions for which surgery was later performed. The specific cell type determined from specimens obtained by needle biopsy was exactly the same as the final histological diagnosis obtained after surgery in 20 lesions. Tissue-core lung biopsy under CT-fluoroscopic guidance for a GGO lesion provides a high degree of diagnostic accuracy but is less reliable for determining the specific cell type. Percutaneous lung biopsy under CT-fluoroscopic guidance for GGO is useful in differentiating malignancy.

An Unusual Cerebral Air Embolism Developing within the Posterior Circulation Territory after a Needle Lung Biopsy

We herein report the case of a 75-year-old woman with a paradoxical cerebral air embolism (CAE). She developed a bilateral visual disturbance at the time of needle puncture during a computed tomography (CT)-guided percutaneous needle lung biopsy in the face down position. The air density within the descending aorta on chest CT suggested the presence of a cerebral air embolism. Brain MRI demonstrated increased signal intensity in the bilateral occipital lobes on diffusion-weighted images. Usually, CAE occurs predominantly in the right hemisphere for anatomical reasons. The face down position and the anatomical features of the right subclavian artery, which diverges backward from the brachiocephalic artery, might explain such a unique distribution of CAE in this patient.

Risks of Transthoracic Needle Biopsy

Transthoracic needle lung biopsy is a commonly performed diagnostic procedure for pulmonary nodules and masses. To make an informed decision about whether to pursue this procedure, doctors and patients must be aware of the possible risks of the procedure. We performed a MEDLINE search, 2003-2012 to identify relevant English-language studies that included at least 100 subjects and reported data on complications of transthoracic needle lung biopsy performed within the last 10 years. We found the most common complication to be any pneumothorax (risk 15-25%), with pneumothorax requiring chest tube occurring less often (risk 4-6%). Hemorrhage, defined as radiographically visualized blood along the needle tract was common, but clinically significant hemorrhage was infrequent (~1%). Rare complications, including air embolism and tumor seeding of the biopsy tract, occurred in fewer than 1% of cases but were potentially serious. We summarize data on factors associated with complications, including patient age, COPD, lesion size and location, and number of punctures. We also provide data on techniques to mitigate severity of pneumothorax post-biopsy, such as rapid patient rollover, manual aspiration, and instillation of substances into the biopsy tract.

Immediate cytology improves accuracy and decreases complication rate in real‐time computed tomography‐guided needle lung biopsy

Computed tomography-guided percutaneous transthoracic needle biopsy (CTNB) of the lung is a well-established diagnostic technique for the evaluation of thoracic lesions. At our institution, we have performed real-time CTNB using automated biopsy needles since 1998 and we introduced immediate cytology in 2004. We evaluate immediate cytology in CTNB to increase the diagnostic accuracy and to reduce the number of inadequate specimens. We retrospectively reviewed a consecutive series of 270 patients (group A: 98 patients before introduction, group B: 172 patients after introduction) who underwent CTNB between 2002 and 2009. We compared the diagnostic performance and the complication rates between two groups. There were no significant differences between groups A and B in patient and lesion characteristics. The rates of one time biopsy were significantly different: 56.1% (55/98) in group A and 69.2% (119/172) in group B. The rates of diagnostic accuracy in groups A and B were 79.6% (78/98) and 94.8% (163/172), respectively; the sensitivity were 74.0% (57/77) and 94.1% (127/135); the specificity were 100% (21/21) and 97.3% (36/37); the rates of major complications were 14.3% (14/98) and 2.9% (5/172). Group B had significantly higher diagnostic accuracy, sensitivity, and a lower complication rate in comparison with group A. CTNB with immediate cytology can improve diagnostic performance and decrease the complication rate. These improvements may help make CTNB less of a burden for patients.

The diagnostic values of CT-guided transthoracic needle lung biopsy and transbronchoscopic lung biopsy for peripheral lung lesions

Objective To explore the values of CT-guided transthoracic needle lung biopsy ( TNLB ) and transbronchoscopic lung biopsy ( TBLB )in the clinical diagnosis by comparing the identification rates of both procedrues for peripheral lung lesions and the incidence rates of procedure-related complications.Methods 249 patients with peripheral lung lesions on radiographic examinations were divided into TNLB group( 153 patients ) and TBLB group ( 96 patients ) based on the method for lung biosy.The rate of lesion identification and the incidence rate of complications were compared between the two groups.Results The rate of lesion identification was markedly higher in TNLB group than in TBLB group ( 77.8％ vs.45.8％ ).The incidence of pneumothorax was similar in the two groups.The incidence of pulmonary hemorrhage was significantly higher in TBLB group than in TNLB group ( 53.1％ vs.7.2％ ),but the rate of bleeding volume of 30 ml or more did not differ significantly between the two groups.The incidence rates of tachycardia and decreased SaO2 were evidently higher in TBLB group than in TNLB group.Conlusions Both biopsies is a less invasive,safer procudure and have their own advantages and disadvantages.Combination of the two procedures is beneficial for the improvement of the identification rate of peripheral lung lesions. Key words: Peripheral lung lesions; Transthoracic needle lung biopsy; Transbronchoscopic lung biopsy

Risk for Complications After Transthoracic Needle Lung Biopsy

Letters6 December 2011Risk for Complications After Transthoracic Needle Lung BiopsySteven Leong, MBBSSteven Leong, MBBSFrom The Prince Charles Hospital, Brisbane, Australia 4032.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-155-11-201112060-00023 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail TO THE EDITOR:I read with interest the important findings by Wiener and colleagues (1) that highlight the 15% (95% CI, 14% to 16%) risk for pneumothorax as a complication of transthoracic needle biopsy for pulmonary nodules. We agree that the need is increasing for clinicians to consider this procedure for evaluation of pulmonary nodules, which are frequently identified in this era of modern imaging intentionally through screening studies and unintentionally through computed tomography (CT) pulmonary angiography (2) and CT coronary angiography (3).This high-quality study provides a reliable estimate of population-level risk. However, as with all good clinical decisions, ...

Presence of EGFR mutation in pathologically non-malignant specimens from computed tomography-guided lung needle biopsies

Activating mutations of the epidermal growth factor receptor (EGFR) gene are characteristic of non-small cell lung cancer (NSCLC). EGFR mutations were previously detected in histologically normal lung tissue around NSCLC tumors. Computed tomography-guided lung needle biopsy (CTNB) is an accurate and useful technique for the diagnosis of lung tumors. However, pathologically non-malignant cases occasionally become apparent following lung tumor resection. In this study, we determined the EGFR mutational status of lung tumors diagnosed as non-malignant in CTNB specimens, but diagnosed as NSCLC following surgical resection. Between 2000 and 2008, 1,109 CTNBs were performed at Okayama University Hospital. Among them, 15 cases were initially diagnosed as non-malignant by CTNB, but diagnosed as NSCLC following surgical resection as a result of a high likelihood of malignancy by clinical findings. Twelve paired DNAs of CTNB and corresponding resected specimens were available to examine the EGFR mutational status using a mutant-enriched PCR assay. EGFR mutations were detected in one out of 12 CTNB specimens and three of the corresponding resected tumors. This case harbored the same EGFR mutation in the CTNB specimen and resected tumor, but not in the distant corresponding non-malignant lung tissue. Our results indicated that the detection of EGFR mutations may therefore aid the diagnosis of NSCLC in pathologically non-malignant CTNB specimens.

Diagnostic efficiency and complication rate of CT-guided lung biopsy: a single center experience of the procedures conducted over a 10-year period

Background Computed tomography (CT)-guided transthoracic lung biopsy is a well-established technique for the diagnosis of pulmonary lesions. The objective of this study was to evaluate the diagnostic efficiency and complication rate of CT-guided lung biopsy in a Chinese population. Methods CT-guided cutting needle lung biopsies were performed in our institution on 1014 patients between January 2000 and October 2010. A chest radiograph was taken after the biopsy. Data about basic patient information, final diagnosis, and complications secondary to biopsy procedure (pneumothorax and bleeding) were extracted. Results The diagnostic efficiency of CT-guided lung biopsy was 94.8%; only 53 patients did not get a final diagnosis from lung biopsy. Final diagnoses found 639 malignant lesions (63.0%) and 322 benign lesions (31.8%). Pneumothorax occurred in 131 patients and 15 required insertion of an intercostal drain. Small hemoptysis occurred in 41 patients and mild parenchymal hemorrhage occurred in 16 patients. The overall complication rate was 18.5%. Conclusions CT-guided cutting needle biopsy of pulmonary lesions is a relatively safe technique with a high diagnostic accuracy. It can be safely performed in clinical trials.

Does Negative Immediate Postprocedure Chest CT Obviate the Need for Delayed Chest X-ray in Patients Undergoing CT-Guided Needle Lung Biopsies

Does Negative Immediate Postprocedure Chest CT Obviate the Need for Delayed Chest X-ray in Patients Undergoing CT-Guided Needle Lung Biopsies

Population-based risk of complications following transthoracic needle lung biopsy of a pulmonary nodule

Background Because pulmonary nodules are found in up to 25% of patients undergoing chest computed tomography, the question of whether to biopsy is becoming increasingly common. Data on complications following transthoracic needle lung biopsy are limited to case series from selected institutions.

Population-Based Risk for Complications After Transthoracic Needle Lung Biopsy of a Pulmonary Nodule: An Analysis of Discharge Records

Because pulmonary nodules are found in up to 25% of patients undergoing computed tomography of the chest, the question of whether to perform biopsy is becoming increasingly common. Data on complications after transthoracic needle lung biopsy are limited to case series from selected institutions. To determine population-based estimates of risks for complications after transthoracic needle biopsy of a pulmonary nodule. Cross-sectional analysis. The 2006 State Ambulatory Surgery Databases and State Inpatient Databases for California, Florida, Michigan, and New York from the Healthcare Cost and Utilization Project. 15 865 adults who had transthoracic needle biopsy of a pulmonary nodule. Percentage of biopsies complicated by hemorrhage, any pneumothorax, or pneumothorax requiring a chest tube, and adjusted odds ratios for these complications associated with various biopsy characteristics, calculated by using multivariate, population-averaged generalized estimating equations. Although hemorrhage was rare, complicating 1.0% (95% CI, 0.9% to 1.2%) of biopsies, 17.8% (CI, 11.8% to 23.8%) of patients with hemorrhage required a blood transfusion. In contrast, the risk for any pneumothorax was 15.0% (CI, 14.0% to 16.0%), and 6.6% (CI, 6.0% to 7.2%) of all biopsies resulted in pneumothorax requiring a chest tube. Compared with patients without complications, those who experienced hemorrhage or pneumothorax requiring a chest tube had longer lengths of stay (P < 0.001) and were more likely to develop respiratory failure requiring mechanical ventilation (P = 0.020). Patients aged 60 to 69 years (as opposed to younger or older patients), smokers, and those with chronic obstructive pulmonary disease had higher risk for complications. Estimated risks may be inaccurate if coding of complications is incomplete. The analyzed databases contain little clinical detail (such as information on nodule characteristics or biopsy pathology) and cannot indicate whether performing the biopsy produced useful information. Whereas hemorrhage is an infrequent complication of transthoracic needle lung biopsy, pneumothorax is common and often necessitates chest tube placement. These population-based data should help patients and physicians make more informed choices about whether to perform biopsy of a pulmonary nodule. Department of Veterans Affairs and National Cancer Institute.

Needle Gauge and Cytological Yield in CT-Guided Lung Biopsy

Rationale and Objectives. The aim of this study is to determine the effect of needle size on the diagnostic yield and complication rate of lung nodule biopsy. Materials and Methods. A total of 209 patients are included in a retrospective study. All patients underwent a needle lung biopsy under computer-tomography-guided guidance. Multiple different needle gauges are used in this study. Results. We found no correlation between the gauge of the needle and the incidence of complications or diagnostic yield associated with lung nodule biopsy. However, there was a statistically significant difference in the number of needle passes and the gauge of the needle (). Conclusion. Using a larger gauge needle does not correlate with an increase in complication rate. However, there is a statically significant decrease in the number of needle passes using a larger gauge needle. While the diagnostic yield comparing small gauge needle and large gauge needle was not statistically different, this lack of difference in yield could be related to the difference in number of passes. The use of larger needle is likely to decrease number of passes, thereby resulting in decreased procedure times.

Diagnostic performance of percutaneous core needle lung biopsy under multi-CT fluoroscopic guidance for ground-glass opacity pulmonary lesions

Objective The diagnostic performance of percutaneous core needle lung biopsy under multi-CT fluoroscopic guidance for ground-glass opacity (GGO) pulmonary lesions was evaluated. Materials and methods Out of 90 patients who underwent CT fluoroscopy-guided core needle biopsy of GGO lesions at our institution, the biopsy results and the final diagnoses were retrospectively compared in 67 patients with available data (one lesion per patient). Diagnostic performance was also compared according to the lesion size (≤10 mm ( n = 8) versus 11–20 mm ( n = 42) versus >20 mm ( n = 17)), the percentage of GGO component (50–90% ( n = 31) versus >90% ( n = 36)), and the length of needle path (≤7 cm ( n = 45) versus >7 cm ( n = 22)). Finally, all 90 cases were reviewed for complications. Results The overall sensitivity, specificity, and accuracy were 97%, 100%, and 97%, respectively. The diagnostic sensitivity and accuracy tended to be lower in smaller lesions (≤10 mm; 86 and 88%, 11–20 mm; 97 and 98%, >20 mm; 100 and 100%, respectively, p > 0.05), and in lesions with lower percentage of GGO component (50–90%; 93 and 94%, >90%; 100 and 100%, respectively, p = 0.21), but statistical significances were not reached. The sensitivity and accuracy were not significantly affected by the length of needle path (≤7 cm; 98 and 98%, >7 cm; 95 and 96%, respectively, p = 1.00). Fourteen patients (16%) developed pneumothoraces, and 13 patients (14%) experienced mild hemoptysis, all of which resolved conservatively. Conclusion The diagnostic performance was satisfactory, and it was considered that the procedure was appropriate for GGO lesions regardless of lesion size, the percentage of GGO component, or the length of needle path. The procedure was also feasible without any major complications.

Efficacy of Fluoroscopy-Guided Cutting Needle Lung Biopsy in Patients with Diffuse Infiltrative Lung Disease

Background: Open lung biopsy is used for diagnosis of diffuse infiltrative lung diseases (DILD), but it is invasive and relatively expensive procedure. Fluoroscopy- guided cutting needle lung biopsy (FCNLB) has merits of avoidance of admission and rapid diagnosis. But diagnostic accuracy and safety were not well known in the diagnosis of DILD. Methods: We included 52 patients (37 men, 15 women) having DILD on HRCT with dyspnea, except the patients who could be confidently diagnosed with clinical and HRCT findings. FCNLB was performed using 16G Ace cut needle (length 1.5 cm, diameter 2 mm) at the area of most active lesion on HRCT. Final diagnoses were made by the consensus. Results: The mean interval between the HRCT and FCNLB was 4.5 days. Most cases were performed one biopsy during 5∼10 minutes. Specific diagnosis was obtained in 43 of 52 biopsies (83%). The most common diagnosis was nonspecific interstitial pneumonia (11 cases) and followed by cryptogenic organizing pneumonia (7 cases), diffuse alveolar hemorrhage and usual interstitial pneumonia (5 cases in each), hypersensitivity pneumonitis (3 cases), tuberculosis and drug induced interstitial pneumonitis (2 cases in each), the others are in one respectively. Mild complication was developed in 9 patients (8 pneumothorax, 1 hemoptysis). Most of complications were regressed without treatment except one case with chest tube insertion for pneumothorax. Conclusion: Fluoroscopy-guided 16 G cutting needle lung biopsy was an useful method for the diagnosis of DILD.

Role of Computed Tomography Fluoroscopy–Guided Cutting Needle Biopsy of Lung Lesions After Transbronchial Examination Resulting in Negative Diagnosis

Introduction: Computed tomography (CT)–guided lung biopsy is occasionally used for the lesions that were diagnosed as nonmalignant by transbronchial examination despite the fact that other clinical data suggested those as malignant. The purpose of this study is to evaluate the outcomes of CT fluoroscopy–guided cutting needle biopsy of lung lesions after transbronchial examination resulting in negative diagnosis. Patients and MethodsWe retrospectively evaluated the outcomes of CT fluoroscopy–guided lung biopsy for 351 lesions (mean size, 2.8 cm) that were found to be nonmalignant by transbronchial examination. Diagnostic yield, including sensitivity and specificity for the diagnosis of malignancy, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. Various variables were analyzed to determine the factors for diagnostic failure. ResultsThe biopsy result was nondiagnostic, true-positive, true-negative, false-positive, or false-negative for 2, 262, 70, 0, or 17 lesions, respectively. Thus, the sensitivity, specificity, PPV, NPV, and accuracy of CT fluoroscopy–guided cutting needle biopsy was found to be 93% (262/281), 100% (70/70), 100% (262/262), 80% (70/87), and 94% (332/351), respectively. There was no significant risk factor for diagnostic failure. ConclusionComputed tomography fluoroscopy–guided cutting needle lung biopsy is a useful technique to correct or confirm negative diagnosis by transbronchial examination.

CT fluoroscopy-guided cutting needle biopsy of focal pure ground-glass opacity lung lesions: Diagnostic yield in 83 lesions

The objective of our study was to retrospectively determine the diagnostic yield of CT fluoroscopy-guided cutting needle biopsy of focal pure ground-glass opacity lung lesions. Biopsies were performed using 20-G coaxial cutting needles for 83 focal pure ground-glass opacity lung lesions (mean lesion size, 12.1mm). After excluding the lesions for which biopsy specimens were unobtainable and final diagnoses were undetermined, the diagnostic yield, including sensitivity and specificity for a diagnosis of malignancy and accuracy, was calculated. The lesions were then divided into 2 groups: the diagnostic failure group, comprising lesions with false-negative results and for which a biopsy specimen was unobtainable; and the diagnostic success group, comprising lesions with true-negative results and true-positive results. Various variables were compared between the 2 groups by univariate analysis. Biopsy specimens were obtained from 82 lesions, while specimens could not be obtained from 1 lesion. Final diagnosis was undetermined in 16 lesions. The sensitivity and specificity for a diagnosis of malignancy were 95% (58/61) and 100% (5/5), respectively. Diagnostic accuracy was 95% (63/66). The 4 lesions in diagnostic failure group were smaller, deeper, and more likely to be located in the lower lobe and further, for those lesions, number of specimens obtained was smaller, compared with 63 lesions in diagnostic success group. However, none of the differences were statistically significant. CT fluoroscopy-guided cutting needle biopsy provided high diagnostic yield for focal pure ground-glass opacity lung lesions.

Cerebral air embolism complicating CT-guided trans-thoracic needle biopsy of the lung

Systemic air embolism is recognized as a rare but potentially fatal complication of trans-thoracic needle biopsy of the lung. We report the case of a young female who developed fatal cerebral air embolism following computed tomography (CT) guided needle biopsy of a lung mass. Immediately after the procedure, the patient went into cardio-respiratory arrest. Despite adequate resuscitation and ventilatory support, she showed little recovery in her neurological status and subsequently died. CT scan of the brain confirmed cerebral arterial air embolism. Radiologists and physicians need to be aware of this rare but potentially fatal complication of needle lung biopsy.

Detection of epidermal growth factor receptor mutations in non-small cell lung cancer tumor specimens from various ways by denaturing high-performance liquid chromatography

背景与目的表皮生长因子受体(epidermal growth factor receptor, EGFR)是最重要的非小细胞肺癌(non-small cell lung cancer, NSCLC)治疗靶点，EGFR突变可预测酪氨酸激酶抑制剂(tyrosine kinase inhibitor, TKI)的疗效。DNA直接测序是检测EGFR突变最常用的方法，同时也作为突变检测的“金标准”，但该方法耗时较长、所需组织量较多且敏感性较低。变性高效液相色谱法是一种快速、自动化、高敏感性的突变检测方法，本研究旨在探讨变性高效液相色谱法(denaturing high-performance liquid chromatography, DHPLC)快速检测NSCLC肿瘤组织EGFR基因突变的诊断价值。方法通过检测已知按不同比例混合的野生型及突变型EGFR质粒DNA，评价DHPLC法的准确性和敏感性。选取经多种途径获取的83例NSCLC患者的冻存肿瘤组织，提取DNA并PCR扩增EGFR外显子19、21，用DHPLC法检测并与直接测序法进行比较。结果当突变型质粒与野生型质粒按1:100混合时，仍可被DHPLC法显著检出，而直接测序法仅可检出1:10水平。83例NSCLC组织标本中，DHPLC法检出22例EGFR突变(突变率26.51%)，3例直接测序法结果为野生型，余19例EGFR突变及61例野生型均与直接测序法结果相符。DHPLC法的敏感度为100%，特异度为95.31%，对经皮细针肺穿刺活检、淋巴结活检以及外科切除等途径获取的肿瘤样本均具有较高的敏感度、特异度。EGFR突变与性别、病理类型显著相关，与吸烟状态、年龄等无相关性。结论DHPLC法可作为NSCLC患者EGFR基因型的初筛方法。