Lung cancer is the leading cause of cancer related death in Taiwan and world wide. The application of low dose helical computed tomography (CT) has been the milestone of lung cancer screening. Recently, The National Lung Screening Trial (NLST) shows screening with low-dose CT could reduce mortality from lung cancer. We conducted this clinical trial to determine the efficacy of low dose CT in early lung cancer screening in Taiwan.

This is a single center, single arm, non-randomized prospective study. We plan to enroll persons between 50 and 74 years in age, who had cigarette smoking of at least 30 pack-years, and, if former smokers, had quit within the previous 15 years. Persons who had previously received a diagnosis of lung cancer, had undergone chest CT within 18 months before enrollment, had hemoptysis, or had an unexplained weight loss of more than 6.8 kg in the preceding year were excluded.

All the participants should complete a questionnaire that covers many topics, including demographic characteristics and smoking behavior. We also plan to collect additional data for planned analyses of cost-effectiveness, and smoking cessation. Lung-cancer got by biopsy and other biospecimens are available to researchers through a peer-review process All screening examinations are planed to perform in accordance with a standard protocol, developed by medical physicists associated with the trial, that specified acceptable characteristics of the machine and acquisition variables. All low-dose CT scans are acquired with the use of multidetector scanners with a minimum of 16 channels.

IDEALCAP radiologists are certified by appropriate agencies or boards and has completed training in image acquisition; radiologists also has completed training in image quality and standardized image interpretation. Images are interpreted first in isolation and then in comparison with available historical images and images from prior IDEALCAP screening examinations.

IDEALCAP primary analysis is the detection rate of lung cancer. Secondary analysis include the detection rate of lung nodule, 5-year survival rate of persons with lung cancer who receive standard surgical treatment, 5-year survival rate of persons with lung cancer who receive alternative treatment other than standard surgical treatment (ex. Radiotherapy, chemotherapy or target therapy), the correlation of CT images and cigarette smoking history, the correlation of CT images and pulmonary function.

Key Word： low dose computed-tomography (LDCT), lung cancer screening

Inclusion Criteria:

• Age 50-74 years
• 30 or more pack-years of cigarette smoking history
• Former smokers: quit smoking within the previous 15 years
• Ability to tolerate CT procedure
• Signed informed consent

Exclusion Criteria:

• Severe uncontrolled heart, vascular, respiratory or endocrine pathology.
• Life-expectancy less than 1 year
• History of lung cancer
• Acute respiratory disease
• Hemoptysis.
• Weight loss more than 6.8 kg in the 12 months prior to eligibility assessment
• Participation in other cancer clinical trial
• Chest CT examination in the 12 months prior to eligibility assessment.