Increased Tumor Size on Angio-CT during Yttrium-90 Compared to Preprocedural Cross-sectional Imaging Studies

Abstract To evaluate changes in liver tumor size between preprocedural cross-sectional imaging and intraprocedural angio-CT among patients undergoing transarterial radioembolization. A total of 128 patients with 153 tumors (58 female, 45.3%; mean age: 64.9 ± 9.86 years) were retrospectively reviewed from January 1, 2021, to December 31, 2023. Baseline patient characteristics and tumor sizes were collected. Radiologic response and progression-free survival (PFS) were analyzed. Statistical analysis was performed using STATA 18.0 (StataCorp, College Station, Texas). The average tumor size increased on angio-CT compared to preprocedural imaging (4.97 ± 2.98 cm vs. 4.55 ± 2.97 cm, p < 0.0001) over a time interval of 37.29 ± 27.70 days, with an average change of 0.42 ± 0.62 cm. Tumors with a delay of more than 1 month between preprocedural imaging and angio-CT showed a greater increase in size (0.59 ± 0.66 cm vs. 0.21 ± 0.49 cm, p = 0.0001). Tumors with a 30% or greater interval size increase were associated with worse PFS (p = 0.0049). Intraprocedural angio-CT can detect tumor growth during radioembolization mapping or administration. Tumor growth is most significant when there is a longer delay between preprocedural imaging and the procedure, and this growth correlates with PFS. Intraprocedural angio-CT provides critical prognostic information that can potentially influence treatment algorithms and should be regarded as a valuable component of interventional oncology procedures.