Under RECIST tumour size was measured unidimensionally rather than bidimensionally , fewer lesions were measured , and the definition of ' progression ' was changed .
It was no longer based on the isolated increase of a single lesion .
Under RECIST tumour size was measured unidimensionally rather than bidimensionally , fewer lesions were measured , and the definition of ' progression ' was changed so that it was no longer based on the isolated increase of a single lesion .