Trial Information

Dx Mediastinal Malignant LAP:Compare PET and EBUS-TBNA

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.