Source 1: American College of Radiology LI-RADS Manual
Notes: Chapter 9 - Treatment Response
Reportability--Liver: Is a diagnosis of Liver Imaging Reporting and Data System (LI-RADS)-Treatment Response (LR-TR) viable nodule seen on imaging and treated with Y-90 radiotherapy reportable? See Discussion.
Patient was initially diagnosed in 2017 with LR-5 lesions in segments 3 and 7 of liver and treated with radiofrequency ablation (RFA). Routine scans in 2019 show no evidence of residual or recurrent disease.
Surveillance imaging in 2020 identifies LR-TR viable segment 3 treatment zone with slowly growing arterially-enhancing nodule as well as increasing arterial enhancement in the neighboring parenchyma. No new LR-4 or LR-5 observations. Patient is not a surgical candidate but is treated with Y-90 radiotherapy.
Per Rule M10, tumors diagnosed more than 1 year apart are multiple primaries. However, there is no clear clinical statement of malignancy in this case.
Do not report LR-TR viable as a new primary. LR-TR viable is a component of the Li-RADS Treatment Response algorithm designed to assess response for path-proven or presumed (e.g., LR-4, LR-5, LR-M) malignancy after locoregional treatment for hepatocellular cancer. LR-TR viable indicates it met the criteria as a viable tumor.