Transbronchial needle aspiration in diagnosing and staging lung cancer: how many aspirates are needed?

Transbronchial needle aspiration has emerged as a key technique for sampling mediastinal adenopathy but variable yields are reported. To determine the number of aspirates needed to optimize yield, we prospectively studied transbronchial needle aspiration and the sequential effect of each successive specimen on diagnostic yield in 79 patients with known or suspected lung carcinoma and mediastinal adenopathy. A total of 451 aspirates were performed in 79 patients (mean, 5.7 aspirates per patient; range, 2-13) with 45 cases (57%) positive for malignancy. A cytologically positive transbronchial needle aspiration occurred with the first aspirate in 42% of patients in whom this procedure established mediastinal nodal involvement. All positive results were achieved with seven or fewer aspirates. Similar yields were obtained for small cell and non-small cell lung cancer after seven aspirates. Rapid on-site specimen cytologic evaluation was used in 55 of 79 cases (70%), with a positive diagnosis obtained in 39 of 55 cases (71%) with on-site evaluation compared with six of 24 cases (25%) performed without on-site evaluation. The data suggest there is a plateau in yield after seven transbronchial needle aspirates, which may be sufficient to obtain an optimal yield in assessing patients with lung cancer and mediastinal adenopathy.

Whole body FDG-PET for the evaluation and staging of small cell lung cancer: a preliminary study.

[F18]-2-deoxy-2fluoro-D-glucose positron emission tomography (FDG-PET) is increasingly used in the diagnosis and staging of lung cancer. Despite its positive performance characteristics in non-small cell lung cancer (NSCLC), the role of FDG-PET in the staging of small cell lung cancer (SCLC) remains to be determined. We designed a prospective study to address this question. Eighteen patients with SCLC were enrolled prospectively to undergo total body FDG-PET in addition to conventional staging procedures (chest computed tomography (CT), abdominal CT, cranial CT or magnetic resonance imaging (MRI), and bone scan/bone marrow biopsy). The agreement between FDG-PET and conventional staging modalities in identifying the presence or absence of metastatic disease was compared using the Veterans Administration (VA) cooperative staging system for staging. Overall staging by FDG-PET agreed with conventional staging exams in 15/18 (83%) patients (kappa=0.67), which included eight extensive and seven limited cases. FDG-PET showed more extensive disease in two of the three patients for which FDG-PET and conventional staging disagreed. These data suggest that total body FDG-PET may be useful in the staging, treatment planning, and prognostication of SCLC. Whether FDG-PET will replace other more established staging modalities remains to be determined by larger prospective randomized controlled studies.