Early Results of Lung Cancer Screening and Radiation Dose Assessment by Low-dose CT at a Community Hospital

Background

The National Lung Screening Trial showed a reduction in overall and cancer-specific mortality for patients screened with low-dose computed tomography (LDCT) versus chest radiograph. Some question whether this can be achieved in community healthcare settings. Our aim was to analyze lung cancer screening outcomes and administered radiation dose using LDCT scans at a community hospital.

Patients and Methods

We retrospectively reviewed the records of 680 patients who underwent LDCT between June 2014 and December 2015, and who met Centers for Medicare and Medicaid Services lung cancer screening criteria: asymptomatic, aged 55 to 77 years, smoked within the last 15 years, and ≥ 30 pack-year history. Effective and absorbed doses were calculated and correlated with gender and body mass index.

Results

Among the 133 patients (19.6%) with a positive screening result (Lung Imaging Reporting and Data System score of 3 or 4), 18 lung cancers were identified in 16 patients, 56.3% (9 of 16) of which were stage I non–small-cell lung cancer. The false-positive rate was 82.8% (95% confidence interval, 73.6%-89.8%). Mean estimated effective dose using dose length product and size-specific dose estimate using water equivalent diameter were 1.2 mSv and 3.7 mGy for women and 1.4 mSv and 3.9 mGy for men, respectively. All dosing metrics were strongly correlated with body mass index (P < .0001).

Conclusions

Over half of screening patients diagnosed with non–small-cell lung cancer in our community had stage I disease, which we anticipate translating into significantly improved mortality. Patient radiation dose from LDCT scans is approximately one-fifth that from standard CT chest examinations.