RECIST 1.1 Solid-Tumor Response Assessment — free guideline decision tool

Turn RECIST 1.1 into a tool: enter the target-lesion sum of diameters (baseline / nadir / current) plus non-target and new-lesion status to derive the target-lesion response (CR/PR/SD/PD) and overall response. Instant, browser-side.

CR: all target lesions gone, all pathological nodes short axis < 10 mm. PR: SLD ≥30% below baseline. PD: SLD ≥20% above nadir AND ≥5 mm absolute increase (both required), or an unequivocal new lesion. SD: neither PR nor PD.

Standardized response read-out for solid-tumor follow-up — oncologic imaging reports and trial eligibility. Lesion measurement and target selection are done by the radiologist.

PR is judged against baseline, PD against nadir — a lesion may rebound slightly from nadir yet remain PR if still ≥30% below baseline and short of the PD threshold. PD needs both the 20% relative and the 5 mm absolute increase; this prevents small lesions from being called progression on percentage alone. Any unequivocal new lesion, or unequivocal non-target progression, makes the overall response PD regardless of target-lesion change. Target selection: long axis ≥10 mm (nodal short axis ≥15 mm), ≤5 targets total and ≤2 per organ.

For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.