68Ga-DOTATATE PET/CT Response Criteria
| Response category | Description |
|---|---|
| Complete response | Disappearance of all tracer-avid lesions or If residual anatomic abnormality on CT with tracer uptake indistinguishable or less than background physiologic uptake |
| Partial response | Reduction in intensity of uptake by one modified Krenning score* in at least 1 tumor site associated with decrease/stable in size on CT (if measurable) or PET (if nonmeasurable on CT) or Reduction in size of tracer-avid lesions on CT (if measurable) regardless of intensity of uptake |
| Stable disease | Not partial response or progressive disease |
| Progressive disease | Development of new tracer-avid lesions or Increase in the size of the tracer-avid lesions on CT (if measurable) or on PET (if nonmeasurable on CT) regardless of intensity of uptake† |
* Modified Krenning score, 0 = no uptake; 1 = uptake < liver; 2 = lesion uptake similar to liver; 3 = uptake > liver but < spleen; 4 = uptake ≥ spleen.
↵†Rarely an increase in the size of the lesion can be seen in responsive lesions. This may be associated with an increase in central hypodensity/necrosis on CT and a decrease in peripheral tracer uptake on PET. In this circumstance, a confirmatory follow-up study or correlation with other imaging modalities may be required.