Light therapy

Hi everyone. First time using this and first ever dermatology appointment today. So I scored 11.9 on the pasi, I got new creams and am starting light therapy later this week. Im totally new to all of this evening though I have had psoriasis for 30years, my GP never referred me, just always gave me steroid cream. I would be so grateful for any advice/info about my score and the treatment I am about to have. Thank you