TABLE 3.

Comparison of WHO Response Criteria and RECIST (5,8,39,7)

Characteristic	WHO	RECIST	RECIST 1.1
Measurability of lesion at baseline	1. Measurable, bidimensional* (product of LD and greatest perpendicular diameter)	1. Measurable, unidimensional (LD only: size with conventional techniques ≥ 20 mm, with spiral CT ≥ 10 mm)	1. Measurable, unidimensional (LD only: size with conventional techniques ≥ 20 mm, with spiral CT ≥ 10 mm; nodes: target short axis ± 15 mm, nontarget 10- to 15-mm nodes, normal < 10 mm)
	2. Nonmeasurable/evaluable (e.g., lymphangitic pulmonary metastases, abdominal masses)	2. Nonmeasurable: all other lesions, including small lesions; evaluable is not recommended	2. Nonmeasurable: all other lesions, including small lesions; evaluable is not recommended
Objective response	1. Measurable disease (change in sum of products of the LD and greatest perpendicular diameters, no maximal number of lesions specified): CR, disappearance of all known disease, confirmed at ≥4 wk; PR, ≥50% decrease from baseline, confirmed at ≥4 wk; PD, ≥25% increase of one or more lesions or appearance of new lesions; NC, neither PR nor PD criteria met	1. Target lesions (change in sum of LD, maximum of 5 per organ up to 10 total [more than 1 organ]): CR, disappearance of all target lesions, confirmed at ≥4 wk; PR, ≥30% decrease from baseline, confirmed at 4 wk; PD, ≥20% increase over smallest sum observed or appearance of new lesions; SD, neither PR nor PD criteria met	1. Target lesions (change in sum of LDs, maximum of 2 per organ up to 5 total [more than 1 organ]): CR, disappearance of all target lesions, confirmed at ≥4 wk; PR, ≥30% decrease from baseline, confirmed at 4 wk; PD, ≥20% increase over smallest sum observed and overall 5-mm net increase or appearance of new lesions; SD, neither PR nor PD criteria met
	2. Nonmeasurable disease: CR, disappearance of all known disease, confirmed at ≥4 wk; PR, estimated decrease of ≥50%, confirmed at 4 wk; PD, estimated increase of ≥25% in existent lesions or new lesions; NC, neither PR nor PD criteria met	2. Nontarget lesions: CR, disappearance of all nontarget lesions and normalization of tumor markers, confirmed at ≥4 wk; PD, unequivocal progression of nontarget lesions or appearance of new lesions; non-PD, persistence of one or more nontarget lesions or tumor markers above normal limits	2. Nontarget lesions: CR, disappearance of all nontarget lesions and normalization of tumor markers, confirmed at ≥4 wk; PD, unequivocal progression of nontarget lesions or appearance of new lesions; non-PD: persistence of one or more nontarget lesions or tumor markers above normal limits; PD must be “unequivocal” in nontarget lesions (e.g., 75% increase in volume); PD can also be new “positive PET” scan with confirmed anatomic progression. Stably positive PET is not PD if it corresponds to anatomic non-PD
Overall response	1. Best response is recorded in measurable disease	1. Best response is recorded in measurable disease from treatment start to disease progression or recurrence	1. Best response is recorded in measurable disease from treatment start to disease progression or recurrence
	2. NC in nonmeasurable lesions will reduce CR in measurable lesions to overall PR	2. Non-PD in nontarget lesions will reduce CR in target lesions to overall PR	2. Non-PD in nontarget lesions will reduce CR in target lesions to overall PR
	3. NC in nonmeasurable lesions will not reduce PR in measurable lesions	3. Non-PD in nontarget lesions will not reduce PR in target lesions	3. Non-PD in nontarget lesions will not reduce PR in target lesions
		4. Unequivocal new lesions are PD regardless of response in target and nontarget lesions	4. Unequivocal new lesions are PD regardless of response in target and nontarget lesions
Duration of response	1. CR: from date CR criteria are first met to date PD is first noted	1. Overall CR: from date CR criteria are first met to date recurrent disease is first noted	1. Overall CR: from date CR criteria are first met to date recurrent disease is first noted
	2. Overall response: from date of treatment start to date PD is first noted	2. Overall response: from date CR or PR criteria are first met (whichever status came first) to date recurrent disease is first noted	2. Overall response: from date CR or PR criteria are first met (whichever status came first) to date recurrent disease is first noted
	3. In patients who achieve only PR, only period of overall response should be recorded	3. SD: from date of treatment start to date PD is first noted	3. SD: from date of treatment start to date PD is first noted

^*Lesions that can be measured only unidimensionally are considered measurable (e.g., mediastinal adenopathy or malignant hepatomegaly).

LD = longest diameter; CR = complete response; PR = partial response; PD = progressive disease; SD = stable disease; NC = no change.