Defining response to radiotherapy in rectal cancer using magnetic resonance imaging and histopathological scales

Table 11 Study definitions of good response according to magnetic resonance imaging tumour regression grade scales

Ref.	Year	TRG scale used (histological stage based upon)	Scales accurate?	Good response definition	Total (n)	Good responders (n)	Average F/up in months	LR (%) 5 yr	DR (%) 5 yr	DFS (%)	OS (%)
Shihab et al[52]	2011	MRI TRG (based on Mandard)	Yes	TRG 1,2,3	37	20		1	3
Patel et al[6]	2012	MRI TRG (based on Dworak)	Yes	TRG 1,2,3	69	47
Patel et al[5] and Patel et al[7]	2011 and 2012	MRI TRG (based on Dworak)	Yes	TRG 1,2,3	66	32	60	14		Yr. 5: 64	Yr. 5: 72
Yu[53]	2014 (unpublished data from our centre)	MRI TRG (based on Mandard and Dworak)	Yes	TRG 1,2	152	61				DFS, Yr. 5: 83%	DFS, Yr. 5: 90%

LR: Local recurrence; DR: Distant recurrence; DFS: Disease- free survival; OS: Overall survival; TRG: Tumour regression grade.