Lung cancer screening with low-dose chest CT: current issues

Radiological Report of Pilot Study for the Korean Lung Cancer Screening (K-LUCAS) Project: Feasibility of Implementing Lung Imaging Reporting and Data System

Objective

To report the radiological results of a pilot study for the Korean Lung Cancer Screening project conducted to evaluate the feasibility of lung cancer screening using low-dose chest computed tomography (LDCT) in Korea.

Materials and Methods

The National Cancer Center and three regional cancer centers participated in this study. Asymptomatic current or ex-smokers aged 55–74 years with a smoking history of at least 30 pack-years who had used tobacco within the last 15 years were considered eligible. In total, 256 participants underwent LDCT November 2016 through March 2017. The American College of Radiology Lung Imaging Reporting and Data System (Lung-RADS) was used to categorize the LDCT findings.

Results

In total, 57%, 35.5%, 3.9%, and 3.5% participants belonged to Lung-RADS categories 1, 2, 3, and 4, respectively. Accordingly, 7.4% participants exhibited positive findings (category 3 or 4). Lung cancer was diagnosed in one participant (stage IA, small cell lung cancer). Other LDCT findings included pulmonary emphysema (32.8%), coronary artery calcification (30.9%), old pulmonary tuberculosis (11.7%), bronchiectasis (12.9%), interstitial lung disease with a usual interstitial pneumonia pattern (1.2%), and pleural effusion (0.8%).

Conclusion

Even though the size of our study population was small, the positive rate of 7.4% was like or lower than those in other lung cancer screening studies. Early lung cancer was detected using LDCT screening in one participant. Lung-RADS may be applicable to participants in Korea, where pulmonary tuberculosis is endemic.

Overuse of CT and MRI in paediatric emergency departments

The aim of this review is to survey CT and MRI overuse in the paediatric emergency department (ED) population. CT is one of the most important modalities employed in the ED. Not surprisingly, its high accuracy, rapid acquisition and availability have resulted in overuse. An obvious limitation of CT is ionizing radiation; in addition there are economic implications to overuse. Studies from the last two decades have shown increase in paediatric ED CT utilization in the first decade, reaching a plateau forming around 2008, followed by a decrease in the last decade. This decrease occurred in conjunction with campaigns raising awareness to the risks of radiation exposure. Although a trend of decrease in overuse have been observed, great variability has been shown across different facilities, as well as among physicians, with more pronounced overuse in non-teaching and non-children dedicated EDs. The leading types of paediatric ED CTs are head and abdominal scans. Decision rules, such as PECARN for head injury and the Alvarado score for abdominal pain, as well as using alternative imaging modalities, have been shown to reduce CT overuse in these two categories. MRI has the obvious benefit of avoiding radiation exposure, but the disadvantages of higher costs, less availability and less tolerability in younger children. Although anecdotally paediatric ED MRI usage has increased in recent years, only scarce reports have been published. In our opinion, there is need to conduct up-to-date studies covering paediatric CT and MRI overuse trends, usage variability and adherence to clinical protocols.