Hello,
My cavitary lesion went away after I stopped doing the nebs of 7% saline. I replaced the nebs with. Dry salt inhaler. I have also been negative for MAC now for a few months. My doctor at Mayo in Rochester is Dr Clain. Following his instructions to continue the Big 3 and raise the head of my bed 4” may have contributed to the cavity collapsing, as well. I did go against his advice and stopped nebulizing in Nov 2021. I do not produce sputum easily and the twice daily nebs may have contributed to the cavity? Purely anecdotal but it worked for me. Good luck!