Iodine-125 Seed Strand Implantation in Combination with TACE for Treatment of HCC with Tumor Thrombus
A recent study from researchers in Shanghai, China published their findings on comparing Iodine-125 (I-125) seed strand implantation in conjunction with transarterial chemoembolization (TACE) versus TACE alone in treatment of patients with hepatocellular carcinoma (HCC) and tumor thrombus. This retrospective study included 76 patients (20 in the I-125 and TACE group, 56 in TACE alone group) with overall survival as the primary end-point. Inclusion criteria consisted of Childs-Pugh A and B patients with intrahepatic HCC single tumor > 5 cm or multiple tumors > 3 cm) with type II tumor thrombus (involvement of right or left portal vein but not main portal vein). TACE was performed with epirubicin and lipiodol. I-125 implantation was performed through a single, percutaneous portal venous access with deployment of the I-125 strand to span the portal vein tumor thrombus. The mean I-125 dose was 62.6 Gy. The authors demonstrated a longer overall survival in the I-125 seed strand implantation group (28.0 vs 8.7 months in a propensity score matched cohort, P = .001). Using modified Response Evaluation Criteria in Solid Tumors, intrahepatic disease control rate favored the combined therapy group (60% versus 28.6%, P = .012) while tumor thrombus disease control rate was significantly improved in the combination therapy group (90% vs 33.9%, p < .001). There were no serious adverse events. Of note, the combined therapy group also received more additional TACE treatments during the follow up period. The authors conclude that combined treatment of HCC with portal vein tumor thrombus with TACE and I-125 seed strand is safe and effective.
Figure 2. (a) The 125I seed strand prepared for implantation. (b) Portography of a 65-year-old man shows filling defects in the right portal vein (arrows). (c) The 125I seed strand is located at the target position (arrow) and delivered through the 5-F sheath. (d) The 5-F sheath is removed and the transhepatic puncture track is occluded with the use of 3 3 coils (arrow). (e) Hepatic angiography (arrows) is immediately performed after the 125I seed strand implantation.
This paper evolves the limited prior research on usage of Iodine-125 seed implantation for treatment/control of tumoral thrombus in patients with HCC. The reported outcomes, specifically overall survival and disease control rates, are exciting and intriguing. Portal vein tumoral thrombus is an important diagnostic finding, limiting treatment options and purporting poor prognosis. Limitations of this study include the retrospective nature, small sample size (19 patients ultimately in the propensity-score matched analysis), homogeneous population (Chinese study, hepatitis B), and disparate number of future TACE procedures. Technical success rate and procedure duration may prove inhibiting in other patient populations. How this compares to other treatments directed at treating/controlling portal vein tumoral thrombus, such as radioembolization and SBRT, would be interesting for future research. Percutaneous implantation of I-125 seed strand could prove to be another weapon in our armamentarium against HCC. Ultimately, further research is required to determine if/where this falls in the treatment paradigm for HCC.
Zhang, ZH, Zhang W, Gu JY, et al. Treatment of Hepatocellular Carcinoma with Tumor Thrombus with the Use of Iodine-125 Seed Strand Implantation and Transarterial Chemoembolization: A Propensity-Score Analysis. J Vasc Interv Radiol. 2018; 29: 1085-1093.
David M Mauro, MD
Department of Radiology
Vascular and Interventional Radiology
University of North Carolina