Please note: lesion = tumor
To measure localized changes:
Targeted: Tumors that have been measured and then compared with follow-up scan
Non-targeted: Tumors that were present and have been noted, but measurements have not been taken
Complete Response (CR): Disappearance of all non-target lesions and normalization of tumor marker level
Incomplete Response – Stable Disease (SD): Persistence of one or more non-target lesion(s) or/and maintenance of tumor marker level above the normal limits
Progressive Disease (PD): Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions (1)
Radiation technology is still developing and is not perfect. As noted, incomplete response and stable disease are combined. This may take in account the thickness of the CR plate measuring 1 cm and other notable insufficiency inherent to the current technology.