TABLE 4.
Response Definitions for Clinical Trials: Lymphoma Response (33)
| Response | Definition | Nodal masses | Spleen, liver | Bone marrow |
|---|---|---|---|---|
| CR | Disappearance of all evidence of disease | (a) 18F-FDG–avid or PET-positive before therapy must be PET-negative after therapy; mass of any size is permitted if PET is negative; (b) variably 18F-FDG–avid or PET-negative; regression to normal size on CT | Not palpable, nodules disappeared | Infiltrate has cleared on repeated biopsy; if indeterminate by morphology, immunohistochemistry should be negative for CR |
| PR | Regression of measurable disease and no new sites | ≥50% decrease in SPD of up to 6 largest dominant masses; no increase in size of other nodes; (a) 18F-FDG–avid or PET-positive before therapy; one or more PET-positive at previously involved site; (b) variably 18F-FDG–avid or PET-negative; regression on CT |
≥50% decrease in SPD of nodules (for single nodule in greatest transverse diameter); no increase in size of liver or spleen | Irrelevant if positive before therapy; cell type should be specified |
| SD | Failure to attain CR/PR or PD | (a) 18F-FDG–avid or PET-positive before therapy; PET positive at prior sites of disease and no new sites on CT or PET; (b) variably 18F-FDG–avid or PET-negative; no change in size of previous lesions on CT | ||
| Relapsed disease or PD | Any new lesion or increase of previously involved sites by ≥50% from nadir | Appearance of new lesions > 1.5 cm in any axis, ≥50% increase in SPD of more than one node, or ≥50% increase in longest diameter of previously identified node > 1 cm in short axis; lesions PET-positive if 18F-FDG–avid lymphoma or PET-positive before therapy | >50% increase from nadir in SPD of any previous lesions | New or recurrent involvement |
CR = complete remission; PR = partial remission; SPD = sum of product of diameters; SD = stable disease; PD = progressive disease.