is it common to get chest CT 6 months after starting big 3 for MAC?

I'm approaching 6 months after starting the big 3 to treat MAC and want to safely and accurately determine the status of my infection. I was diagnosed via bronchoscopy and have never generated a positive sputum sample otherwise. Each month since starting drug therapy, I've submitted a sputum sample. My samples are mostly saliva, even after going to the sputum induction lab. Even if I found a way to submit better quality sputum samples, no one knows whether that sputum came from a part of my lungs that's impacted by MAC.

At the 6 month mark, should I get a low-dose CT scan? Would it be informative after just 6 months? If the past 6 months of drug therapy were effective, would that result in noticeable improvement in nodules and tree-in-bud opacities in that amount of time? Or would a CT that looks the same as the baseline indicate that the drugs are effective, given this time frame? If it's prudent to reschedule the CT for later, when do you recommend I schedule it for and why?