Aims and objectives
Often,
more than one nodule is found in lung cancer screening participants,
but the association of the nodule count with lung cancer probability is unclear.
The purpose of this study was to assess the prevalence of multi-nodularity and lung cancer probability in the baseline screening round of the Dutch-Belgian Randomized Lung Cancer Screening Trial.
Methods and materials
In the Dutch-Belgian randomized lung cancer screening trial (NELSON),
launched in 2003,
7557 participants in the screening arm underwent low-dose chest CT scanning.
The design of the NELSON trial including participant selection and lung nodule management have been published previously (1,
2).
The NELSON trial was approved by the Dutch Minister of Health and the ethics board of each participating center.
All participants gave written informed consent.
The CT scanning protocol consisted of four screening rounds each using a 16-detector CT scanner (three Sensation-16,
Siemens...
Results
3392 participants (84.4% male,
median age 59 years) had 7258 nodules at baseline CT screening.
Of these,
1741 participants (51.3%) had one nodule,
802 (23.6%) had two nodules,
356 (10.5%) had three nodules,
193 (5.7%) had four nodules and 300 (9.9%) had more than four nodules.
Figure 1 shows the distribution of the nodule count per participant.
In total,
62 nodules were confirmed to be malignant in the immediate period after the baseline screening CT.
The percentage of participants with lung cancer was 1.6% in...
Conclusion
Multi-nodularity is common in baseline CT lung cancer screening.
The probability of lung cancer tends to differ by number of detected prevalent nodules.
There seems to be a slight peak in percentage of malignancy in participants with four nodules.
The malignant nodule generally had the largest volume of all detected nodules.
References
Zhao YR,
Xie X,
de Koning HJ,
et al.
NELSON lung cancer screening study.
Cancer imaging 2011;11:S79-84
Xu DM,
Gietema H,
de Koning H et al.
Nodule management protocol of the NELSON randomised lung cancer screening trial.
Lung Cancer 2006;54(2):177-84