The effects of inspiratory muscle training with pulmonary rehabilitation on NSCLC patients during radiation therapy: A pilot clinical study

Background: The effects of inspiratory muscle training (IMT) with pulmonary rehabilitation (PR) on patients with non-small cell lung cancer (NSCLC) receiving radiotherapy (RT) have not previously been reported. This pilot study aimed to determine the effectiveness of IMT with PR on respiratory muscles and exercise capacity of NSCLC patients receiving RT. Methods: We retrospectively analyzed 20 patients who underwent RT for NSCLC. The rehabilitation included IMT, stretching, strengthening, and aerobic exercises three times a week for 4 weeks with concurrent RT. IMT training lasted 10 min, consisting of one cycle of 30 breaths using the Powerbreathe KH1 device in the hospital by a physical therapist. Patients underwent two IMT sessions at home daily at an intensity of approximately 30%-50% of the participant's maximum inspiratory muscle pressure (MIP) using the threshold IMT tool. We analyzed the results from the respiratory muscle strength test, pulmonary function test, 6-min walk test (6MWT), cardiopulmonary function test, cycle endurance test (CET), Inbody test, grip measurement, knee extensor/flexor strength measurement, Cancer Core Quality of Life Questionnaire (EORTCQ-C30), and NSCLC 13 (EORTC-LC13). Results: There were no adverse events during evaluation and IMT with PR. MIP (60.1 +/- 25.1 vs. 72.5 +/- 31.9, p = 0.005), 6MWT (439.2 +/- 97.1 vs. 60.7 +/- 97.8, p = 0.002), CET (181.39 +/- 193.12 vs. 123.6 +/- 87.6, p = 0.001), knee extensor (14.4 +/- 5.3 vs. 17.4 +/- 5, p = 0.012), and knee flexor (14.0 +/- 5.2 vs. 16.9 +/- 5.5, p = 0.004) significantly improved after IMT with PR. Conclusion: IMT with PR appears effective on respiratory muscles and exercise capacity without adverse events in NSCLC patients who underwent RT.