6 - Lung Cancer: Low-dose Helical Computed Tomography

Abstract

This chapter presents the usefulness and pitfalls of a mass screening for lung cancer with low-dose helical CT (LDHCT) scan and presents the Mayo Clinic project of lung cancer screening LDHCT scan. The helical CT scan has the highest sensitivity for the detection of pulmonary nodules compared to other examinations. LDHCT might be a promising method for screening early lung cancer at health examinations. Most of the lung cancers detected in lung cancer screening with LDHCT are stage I. Well-designed clinical trials are necessary to establish the guidelines for mass screening for lung cancer. The Mayo Clinic investigated the trial of LDHCT screening for lung cancer initiated in 1999. High-risk participants more than 50 years of age and with 20 pack-years of smoking or more were listed. Low-dose helical CT with multislice CT (MSCT, four detectors) was used under conditions that included 5 mm collimation with 3.75 mm reconstruction. At least one noncalcified nodule was detected in 780 of 1520 (51%) participants on the baseline CT scan, and a total of 3356 noncalcified nodules were detected in the 1118 participants from 2000 through 2003. Some participants with pulmonary nodules undergo thoracic surgery and/or biopsies, such as transbronchial lung biopsy (TBLB) for benign disease. The rate of invasive procedures, such as TBLB and conventional thoracotomy, for benign lesions detected by computed tomography (CT) screening was 22-55% of participants with abnormal CT findings. The General Rule for the Clinical and Pathological Record of Lung Cancer (GRCPRLC) notes that further clinical examinations are necessary for cases with nodules >10 mm in diameter in helical CT screening for lung cancer.