Table 1.

Criteria for clinical assessment of response to neoadjuvant therapy in the OPRA trial^a

Modality	Criteria
	Complete response	Near complete response	Incomplete response
Endoscopy	Flat white scar, telangiectasia, no ulcer, no nodularity	Irregular mucosa, small mucosal nodules or minor mucosal abnormality, superficial ulceration, mild persisting erythema of scar	Visible tumor
Digital rectal exam	Normal	Smooth induration or minor mucosal abnormalities	Palpable tumor nodules
MRI
T2 weighted	Only dark T2 signal, no intermediate T2 signal, no visible lymph nodes	Mostly dark T2 signal, some remaining intermediate signal, or partial regression of lymph nodes	More intermediate than dark T2 signal, no T2 scar, or no regression of lymph nodes
Diffusion weighted	No visible tumor on B800-B1000 signal or Lack of or low signal on ADC mapb	Significant regression of B800-B1000 signal or minimal residual signal on ADC map	Insignificant regression of B800-B1000 signal or obvious low signal on ADC map

^aFrom Yuval et al. 2020, J. Gastrointest. Surg. 24:1880–1888; with permission.

^bUniform linear signal in wall above the tumor is acceptable. ADC, apparent diffusion coefficient.