What Does Ptb Regressing Mean? I Have 3 Year Old

what does ptb regressing mean? i have 3 year old daugther took 6 months medicine for primary complex and yesterday she had finished taking meds and the ped-pulmonologist ask for chest x-ray, and the impression is ptb is regressing. do i need to stop the medicines or should i continue for another 3 months? i hope i get a response from you. thank you.