iRECIST Time-Point Response (Immunotherapy Trials)
iRECIST time-point response for clinical trials testing immunotherapeutics (Seymour and colleagues, Lancet Oncology 2017).
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Target-lesion response by RECIST 1.1 criteria
- Partial response in target lesions by RECIST 1.1 criteria.
- Non-target-lesion response
- Neither complete response nor progression in non-target lesions.
- Whether new lesions are present
- No
- Whether iUPD was recorded at the IMMEDIATELY PRECEDING assessment
- Yes
- Target disease
- No
- Non-target disease
- No
- New lesions
- No
- Whether RECIST 1.1 defined progression is now present in a lesion category…
- No
Result: iPR, after a prior iUPD.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- iUPD
- Unconfirmed progression. The first scan meeting RECIST 1.1 progression criteria. Never assign progression on one scan.
- iCPD
- Confirmed progression. Requires a prior iUPD plus FURTHER increase on a scan 4 to 8 weeks later.
- Reset
- Shrinkage against baseline after iUPD resets the bar: iCR, iPR or iSD IS assigned, unlike RECIST 1.1.
- Persistence
- No change from a prior iUPD remains iUPD. Confirmation needs further increase, not persistence.
- New lesions
- Produce iUPD, not progression. Recorded separately as NLT/NLNT, never added to the baseline target sum.
- Thresholds
- Target: 5 mm further increase. Non-target: any increase, need not be unequivocal. New lesions: 5 mm NLT, any NLNT, or more lesions.
- Scope
- A trial data-collection standard. Not a decision to continue or stop therapy.
What you enter
- Target-lesion response by RECIST 1.1 criteria
- Non-target-lesion response
- Whether new lesions are present.
- Whether iUPD was recorded at the IMMEDIATELY PRECEDING assessment.
- Target disease: further increase in the sum of measures of AT LEAST 5 MM since the prior iUPD.
- Non-target disease: ANY further increase since the prior iUPD.
- New lesions: sum of measures of new lesion-target up by at least 5 mm, OR any increase in new lesion-non-target, OR additional new lesions, since the prior iUPD.
- Whether RECIST 1.1 defined progression is now present in a lesion category that had NOT previously met progression criteria.
Full field descriptions
- Target-lesion response by RECIST 1.1 criteria [iCR = Complete response in target lesions by RECIST 1.1 criteria. iPR = Partial response in target lesions by RECIST 1.1 criteria. iSD = Stable disease in target lesions by RECIST 1.1 criteria. iUPD = Target lesions meet RECIST 1.1 criteria for progression. Under iRECIST this is unconfirmed.]
- Non-target-lesion response [iCR = Complete response in non-target lesions. non-iCR-non-iUPD = Neither complete response nor progression in non-target lesions. iUPD = Non-target lesions meet RECIST 1.1 criteria for unequivocal progression. Under iRECIST this is unconfirmed.]
- Whether new lesions are present. A new lesion produces iUPD but does not by itself confirm progression, and new lesions are recorded separately rather than added to the baseline target sum of measures.
- Whether iUPD was recorded at the IMMEDIATELY PRECEDING assessment. REQUIRED: without a prior iUPD, iCPD is not reachable at all, because progression is never confirmed on a single scan.
- Target disease: further increase in the sum of measures of AT LEAST 5 MM since the prior iUPD. Read only when iUPD was recorded previously and this assessment is still progressed.
- Non-target disease: ANY further increase since the prior iUPD. It explicitly NEED NOT meet RECIST 1.1 criteria for unequivocal progression, so the 5 mm bar does not apply here.
- Whether RECIST 1.1 defined progression is now present in a lesion category that had NOT previously met progression criteria. This also confirms iCPD.
How this is calculated
Seymour L, Bogaerts J, Perrone A, et al. iRECIST: guidelines for response criteria for use in trials testing immunotherapeutics. Lancet Oncol. 2017;18(3):e143-e152. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.