Abstract Rationale Patients eligible for lung cancer screening (LCS) are at risk for structural abnormalities including emphysema. Quantitative CT analysis enables objective assessment of emphysema burden. Emphysema hole-size has been linked to more severe disease and increased mortality. The clinical implications of emphysema hole-size and its impact on emphysema progression have been poorly described. Methods The Temple Healthy Chest Initiative is an urban, health system-wide lung cancer screening program. LDCTs were processed with an AI-assisted quantitative CT platform (AVIEW, Coreline Inc., Seoul, Korea). Emphysema was quantitated using percent low attenuation areas (%LAA) at -950 and -910HU. Progression was evaluated by comparing between-group differences in %LAA change across sequential LDCTs. Emphysema hole-size was calculated for each baseline LDCT. Changes in %LAA over sequential LDCT between 1mm and 1mm hole-size groups were performed using the nonparametric Mann-Whitney U test. Results 51 patients (30 female, 21 male, median age 63) were included in the analysis at baseline LDCT. 35 (69%) and 16 (31%) individuals had two and three repeat LDCT during the follow-up period. 33 (65%) patients had 1mm emphysema hole-size while 18 (35%) had 1mm on baseline LDCT. Baseline emphysema was higher in the 1mm-hole group. Between baseline and first follow-up LDCT, there was a median (IQR) change in %LAA-950 of 0 (1) and -3.5 (3.25) for 1mm-hole and 1mm-hole group respectively (p 0.001). The median (IQR) change in %LAA-910 was 1 (11) and -14 (19) for 1mm-hole and 1mm-hole group respectively (p 0.001). Between baseline and second LDCT, there was a median (IQR) change in %LAA-950 of 0 (1) and -3 (6.5) for 1mm-hole and 1mm-hole group respectively (p 0.001). The median (IQR) change in %LAA-910 was 3 (9) and -11 (19.5) for 1mm-hole and 1mm-hole group respectively (p 0.001). Between baseline and third LDCT, there was a median (IQR) change in %LAA-950 of 1.5 (7) and -4 (6) for 1mm-hole and 1mm-hole group respectively (p = 0.05). The median (IQR) change in %LAA-910 was 9 (20.5) and -13 (13) for 1mm-hole and 1mm-hole group respectively (p = 0.003). Conclusion Results from the THCI LCS cohort demonstrate patients with emphysema hole sizes 1mm at the time of baseline LDCT was associated with significantly greater emphysema progression on quantitative CT over time compared to patients with emphysema hole sizes 1mm. Larger hole sizes may represent areas of local air-trapping which may change over time and with changes in airway resistance. Additional research is needed to further solidify this relationship. This abstract is funded by: None
Deng et al. (Fri,) studied this question.