Purpose: To evaluate the natural history of incidentally identified enhancing nodules on cone beam computed tomography (CBCT) during Y90 mapping for hepatocellular carcinoma (HCC).
Material and Methods: A retrospective analysis of 180 patients with HCC who underwent mapping angiography with CBCT prior to radioembolization from August 2015 to June 2019 was performed. Inclusion criteria included patients with solitary HCC, CBCT of the target lesion and normal liver parenchyma, and follow-up cross-sectional imaging. Patients with nodules ≥ 3 mm that did not meet imaging criteria for HCC were analyzed.
Results: 100 patients met inclusion criteria. 56% of patients demonstrated a total of 154 enhancing nodules on CBCT of which 8.5% progressed to HCC. The mean primary tumor size was 29 mm (range: 10.2-189.0 mm). 53% of patients had one enhancing nodule, 37% had 2–9 nodules, and 10% had ≥ 10 nodules. Mean nodule size was 6.75 mm (range: 3.0-16.3mm). The mean follow-up interval after radioembolization was 345 days (range: 28-1078 days). 20%, 4.8%, and 50% of patients with 1, 2-9, and ≥ 10 nodules progressed to HCC, respectively. Patients with ≥10 nodules had increased risk of nodule progression to HCC compared to those with <10 nodules (P-value= .030). No statistically significant differences were identified in baseline neutrophil to lymphocyte ratio, targeted HCC characteristics (size, vascular invasion, margin irregularity, enhancement pattern, and satellite lesions), and nodule size between those with nodule progression to HCC and those without. Baseline alpha-fetoprotein (AFP) was correlated (P= .035) with progression (median: 61.50 versus 8.60).
Conclusions: Most incidentally identified enhancing nodules ≥ 3mm on CBCT do not progress to HCC. Patients with ≥10 nodules or AFP elevation have an increased risk of nodule progression to HCC.