Recurrence after Bi-lateral mastectomy and full hysterectomy

Hi ladies, so many amazing stories on here! I was originally diagnosed in August 2013 with 1cm invasive DCIS. Lumpectomy found a further 5cm mass, which had not been detected on mammogram, ultrasound, or CT scan. I opted for bi-lateral mastectomy as there was no way of knowing if it was in the left side. Mastectomy revealed another 3 DCIS on the right side. I have had full reconstruction. Took tamoxifen for 8 months but was very sick so oncologist suggested full hysterectomy, which I did (was pre-menopausal). Fast forward 4.5 years and have been diagnosed with DCIS in exactly same spot on right side. Review of yearly ultrasounds shows it’s been there since first ultrasound end 2014. Have had a lumpectomy and will do radiation and hormone therapy, although not sure what. Have had a bone scan and CT which are both clear. My concern is it’s been there since last time, and I have a history of tumours not being visible on scans so not very confident in bone and CT results. Would a Pet scan be more accurate? Have yet to see oncologist but there’s been no mention of chemo either. I don’t want to be dealing with Mets in a few years. Would love to hear from anyone whose been through similar or any who have suggestions I can ask oncologist. Thanks everyone!!