Radiographic Parameters in Predicting Outcome of Patients with Hepatocellular Carcinoma Treated with Yttrium-90 Microsphere Radioembolization
Table 1
Response to treatment graded by Morphology, Attenuation, Size, and Structure (MASS) criteria*.
Response category
MASS criteria description
Favorable response
No new lesions and either of the following: (1) decrease in tumor size ≥20%; (2) ≥1 predominantly solid enhancing lesion with marked central necrosis or marked decreased attenuation
Indeterminate response
Does not fit criteria for favorable or unfavorable response
Unfavorable response
Either of the following: (1) increase in tumor size ≥20% without marked central necrosis or marked decreased attenuation; (2) new metastases, marked central fill-in, or new enhancement of a previously homogeneously hypoattenuating, nonenhancing mass