Beach sunrise, you may want to add Signatera test into your mix of arsenals. Its a blood test which is suppose to help with detecting whether there are cancer cell in your body or not. Though this is also not 100%. If the tumor is sheding cell into blood while the blood was drawn then it will detect it, else it wont, a timing issue too. But at least you have another data point. Most people do it every 3 months thru your normal oncologist and I've just request it as well.
Wife to my DH
8/10: Dx 45 M, father of 2 boys(5 and 3), Greater Chicago region
Tumor location: left side, sigmoid colon, CEA 945
Stage 4, Colorectal Poorly differentiated Adenocarcinoma,
Mets: Lymph nodes Cervical, Chest, abdominal, pelvis
Biomarker: Tumor burden 2.1, MSS, KRAS/BRAF/NRAS wild, RAD51B, TP53, APC, ZNF217
9/13: 2nd CEA scan 1008