After TACE, ablation or radioembolisation, viable tumour is arterial-phase hyperenhancement, washout or enhancement like pre-treatment in or along the treated lesion; LR-TR viable / non-viable / equivocal — and mRECIST measures the viable part.
Orient first
- LI-RADS treatment response (LR-TR) applies after locoregional therapy (verify version).
- Lipiodol after TACE is hyperdense on CT and hides enhancement — subtraction MRI helps.
- After radioembolisation, perilesional arterial enhancement can persist for months without tumour.
Acquire the study
- Unenhanced, late arterial, portal venous and delayed phases.
The manoeuvre
- Unenhanced series: lipiodol distribution (dense).
- Late arterial phase: nodular hyperenhancement at the margin or inside — viable.
- Portal venous and delayed phases: washout.
- mRECIST: longest diameter of viable (enhancing) tumour in mm.
- New lesions elsewhere; portal vein.
What confirms it
- LR-TR viable with nodular arterial enhancement or washout in the treated zone.
What licenses you to exclude it
- No enhancement in or along the treated lesion = LR-TR non-viable.
The classic misread
- Calling a thin smooth rim of perilesional enhancement after ablation viable tumour.