Dx Mediastinal Malignant LAP:Compare PET and EBUS-TBNA
Dx Mediastinal Malignant LAP:Compare PET and EBUS-TBNA
Lung cancer is the leading cause of death in Taiwan. The outcomes of the disease vary
 depending on early detection, histologic types and staging. Because the mediastinal
 involvement including lymph node status is a significant prognostic factor for survival,
 lymph node biopsy is necessary for clinical staging of some patients. Although
 fluorodeoxyglucose-positron emission tomography (FDG-PET) is suggested for precise evaluation
 of mediastinum, tissue proof of PET positive lesions are recommended due to its limited
 diagnostic specificity for identifying mediastinal metastases. Cervical mediastinoscopy
 remains the "gold standard" for mediastinal lymph node sampling. However, it is invasive,
 requires general anesthesia. Another new minimally invasive method of mediastinal biopsy is
 real-time endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The
 aim of this study is to compare the accuracy of PET and EBUS-TBNA for correct staging of the
 mediastinum for lung cancer patients.
Lung cancer ranks among the most commonly occurring malignancies and currently is the leading
 cause of cancer-related cause worldwide including Taiwan [1, 2]. Although a lot of research
 focus on the treatment of lung cancer, the prognosis of lung cancer remains dismal and a five
 year survival ate is less than 15% [3]. Unfortunately, early detection of lung cancer is
 still a problem. In a tertiary care hospital in Taiwan, only 27.3% of patients could received
 operation (stage I 15%, stage II 7.5%) [4]. Lymph node staging is also important for
 evaluation the possibility of operation.

 Fluorodeoxyglucose-positron emission tomography (FDP-PET) is now used by oncologist to
 evaluate lung masses, solitary pulmonary nodules and intrathoracic lymph nodes. As the
 technique becomes more widespread, it is now used even as a first line imaging investigation.
 Although PET has a high negative predictive value, it is neither sensitive nor specific to
 differentiate benign from malignant mediastinal lymph nodes [5, 6]. If PET positive
 mediastinal lymph nodes are equal to malignant involvement, some patients might be excluded
 from potentially curative surgery. Several national guideline groups suggest that PET
 positive lymph nodes should be biopsied if it is likely that the result will alter clinical
 management [7, 8].

 "Cervical mediastinoscopy" has been regarded as the "standard procedure" for sampling
 mediastinal lymph nodes. However, these techniques require general anesthesia and could not
 be repeated because of adhesion. Access to hilar nodal stations can be difficult for
 mediastinoscopy. In recent years, one minimally invasive method endobronchial
 ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was used for biopsy of both
 hilar and mediastinal lymph nodes [9]. EBUS-TBNA allows the mediastinal lymph nodes to be
 targeted in the areas accessible to cervical mediastinoscopy, as well as some hilar nodes
 (lymph node stations 2-4, 7, 10-12)[9] .

 Kazuhiro Yasufuku had published the first report of real-time EBUS-TBNA in evaluating
 mediastinal lymphadenopathy in 2004 [10]. Currently, the main indication of EBUS-TBNA is the
 mediastinal nodal staging of NSCLC after recent meta-analyses established the comparable
 sensitivity and specificity of nodal staging by EBUS-TBNA and cervical mediastinoscopy [11].
 Efficacy in evaluation of other disease processes such as sarcoidosis and lymphoma has also
 been established [12].

 Although there were several large studies to compare the diagnostic efficacy of mediastinal
 malignant lymphadenopathy between FDG-PET and EBUS-TBNA, the investigators need to have our
 own data because of high incidence of TB lymphadenitis in Taiwan, where the diagnostic
 accuracy of PET may be lower than other countries.
Inclusion Criteria:

 1. Age older than 18 years

 2. Patient with suspected malignant mediastinal lymphadenopathy

 Exclusion Criteria:

 1. Age younger than 18 years

 2. Bleeding diathesis(INR > 1.4, Platelet count < 10,000/mcl)