Would you ever consider foregoing surveillance CT scans for resected stage II or III colon cancer in favor of circulating ctDNA assays?

As someone who was introduced to CEA in colon surveillance when discovered simultaneously by Gold and LoGerfo in the early 1970s, I am excited by the rapid acceptance of ctDNA in evaluation and management of colon cancer. We know that ctDNA can be positive up to 9 months before a CT scan demonstrates recurrence. However, until there is evidence of the benefit that treating "ctDNA recurrence" early without CT evidence, I feel that both should be simultaneously utilized. Evidence of ctDNA presence might cause us to shorten the interval between follow-up scans.