I had two cavities (both small 1-2 cm) last September. I began IV Amikacin along with the Big 3. I tolerated the IV 10 weeks before tinnitus set in. I was then taken off the Amikacin. My CT scan at 10 weeks showed that one cavity was eliminated and the other was greatly reduced. My CT scan 3 months later showed no cavities. I am currently testing negative and expect to be off the Big 3 at the end of the year. I am wondering why you weren’t started on IV Amikacin or Arikayce as soon as they discovered the cavity? Please research protocols. There are many Facebook groups (MAC, Lung Matters) websites (NTMir) and podcasts (NTMtalk) that can provide you with information. There are also conferences throughout the year that can often be attended via zoom. NTMir has a list of support groups that meet by zoom monthly also. Best of luck.