For more information, Google RECIST
Minimum Target
Lesion Size
Number of
Measurable Lesions
Lesion Measurement
Lymph Node
Measurement
PET
RECIST 1.1
≥ 10mm CT + MR
≥ 15mm Lymph Nodes
≥ 20mm Chest X-Ray
Up to 5 total
2 is maximum per organ
RECIST 1.0
≥ 10mm Spiral CT
≥ 20mm Conventional CT + MR
Up to 10 total
5 is maximum per organ
Bi-dimensional
in mm, not cm
Bi-dimensional
in mm, not cm
≥ 15mm in short axis
None
May be considered to support
CT, for PD and confirmation of
CR.
Not available
Disease Evaluation – Performed by Oncology Staff
PD (Progressive
Disease)
20% Increase in SOD + min.
5mm increase from Nadir
20% increase in SOD from Nadir
Confirmation of CR
and PR (Complete
Response and Partial
Response)
Only required if response is
primary endpoint and not
randomized
After at least 28 days
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Troubleshooting
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Target lesions should remain the same between studies even if
target lesion shrinks below 10mm (15mm for lymph nodes)
The longest axis is always measured irrespective of previously
measured axis (shortest axis for lymph nodes)
New lesions can be added as non-target lesions
Non-target lesions are not measured and can be recorded as a
group if they are in the same organ
CR (complete response)  disappearance of all target lesions
PR (partial response)  30% decrease in SLD of target lesions
PD (progressive disease)  20% increase in SLD of target lesions
Selecting Target Lesions
1. Not necessarily the largest – select the best
defined and reproducibly measurable
2. Imaging consistency is important. Measure
in the same plane of imaging and same
phase of contrast
3. Target measurement rules at follow-up,
measure where the lesion is largest (doesn’t
matter if slice and orientation are different)
4. Lymph Node: only if short axis ≥15mm
5. Bone Mets: Select only if with an identifiable
soft tissue component (blastic lesions are
non-measurable)
6. Splitting and Merging Lesions:
The individual longest diameters of all the
resulting lesions shall contribute to the sum of
diameters
SD (stable disease)  small changes that do not meet above criteria
SOD  Sum of Diameters