Lung Function Assessment of Elexacaftor/Tezacaftor/Ivacaftor Therapy in Cystic Fibrosis Patients With Ventilation/Perfusion SPECT/CT.

The advent of CFTR modulators has marked a breakthrough in cystic fibrosis management. Current monitoring relies on clinical data, spirometry, and CT. We report the interest of functional assessment using ventilation/perfusion (V/Q) SPECT/CT with 99m Tc in 3 patients treated with Elexacaftor/Tezacaftor/Ivacaftor (ETI). Two patients exhibited improvement in lung function on SPECT imaging, consistent with their clinical response, which was more pronounced than the structural changes observed on CT. The third patient exhibited no scintigraphic improvement, consistent with no clinical benefit. These results suggest that, while CT reflects structural changes, V/Q SPECT/CT provides complementary information on regional lung function, enabling early detection of ETI response.