Figure 2.

A potential algorithm for assessment of MSI-H/dMMR rectal cancer treated with immunotherapy, and the suspicion of pseudoprogression. *, assessment with MRI, colonoscopy and digital rectal exam. ^a, in those patients who achieve a clinical complete response with no evidence of residual disease on digital rectal examination, rectal MRI and direct endoscopic evaluation, may be considered in centers with experienced multidisciplinary teams; ^b, continue ICI until 2 years. MRI, magnetic resonance imaging; ICI, immune checkpoint inhibitor; W&W, watch-and-wait; cCR, clinical complete response; MSI-H/dMMR, microsatellite instability-high/deficient mismatch repair. Prefix “i” indicates immune response assigned using iRECIST: iCR, complete response; iPR, partial response; iSD, stable disease; iUPD, unconfirmed progressive disease; non-iCR, no complete response; non-iUPD, unconfirmed progressive disease; iCPD, confirmed progressive disease.