Protocol Design Considerations: Imaging Modalities
- Triphasic CT scans recommended for HCC and neuroendocrine tumors
- Care must be taken in measurement of target lesions on a different modality and interpretation of non-target disease or new lesions, since the same lesion may appear to have a different size using a new modality
- If a site can document that the CT performed as part of a PET–CT is of identical diagnostic quality to a diagnostic CT (with IV and oral contrast) then the CT portion of the PET–CT can be used for RECIST measurements. However, the PET portion of the CT may bias an investigator if it is not routinely or serially performed
- MRI has excellent contrast, spatial and temporal resolution; however, there are many image acquisition variables involved in MRI, which greatly impact image quality, lesion conspicuity and measurement. Chest MRI not recommended due to prevalence of image artifacts and limited global accessibility to MR scanners
- Measurements permissible on non‐axial isotropic CT and non‐axial MRI
