Feasibility of Helical I-125 Seed Implant in the Portal Vein
To evaluate the feasibility of helical iodine-125 (I-125) seed portal vein implantation.
Materials and Methods
Helical I-125 seed implants were placed into the portal vein of healthy pigs through the transjugular (n = 3) or percutaneous transhepatic (n = 3) route. Six pigs received follow-up at 9 weeks after implantation. Blood tests were performed preimplantation, and at 1 and 9 weeks after implantation. Contrast-enhanced computed tomography (CT) and single-photon emission computed tomography combined with CT (SPECT-CT) were acquired after implantation. Post-implantation CT was imported to the treatment planning system (TPS) for dose verification. At 9 weeks after implantation, another CT was performed before histopathological examination.
All implantations were successful, and the helical implants were fixed to the portal vein. CT showed no implant migration or portal vein thrombosis. The average dose to 90% of the target volume calculated from TPS was 68.4 Gy. SPECT-CT revealed an irregular isodose around the implant, in which the hottest spot was near the central portal vein lumen. All pigs were in good condition at the 9-week follow-up. Histopathology studies confirmed no portal vein thrombosis. Pigs showed no signs of bleeding, necrosis, or perforation of the peripheral tissue or organs. Intimal hyperplasia was observed at the two ends of the implant. A mild inflammatory response was detected in the bile duct and adjacent liver tissues, yet there was no apparent inflammation of the hepatic arteries.
The helical I-125 seed implants can be inserted into the portal veins of healthy pigs.
KeywordsPortal vein Tumor thrombus Endovascular brachytherapy Helical I-125 seed implants
Contrast-enhanced computed tomography
Single-photon emission computed tomography
Treatment planning system
Dose to 90% of the target volume
Portal vein tumor thrombus
Main portal vein tumor thrombus
External beam radiotherapy
Dose volume histogram
Analysis of variance
Planning target volume
This study was supported by Jiangsu Provincial Medical Talent funding (Grant Number ZDRCA2016038).
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
This study was approved by the Animal Ethics Committee of Suzhou University in China. The Experimental Animal Center of Suzhou University provided six pigs that were single-housed. Food intake was monitored, and the animals were housed according to the standard procedures. All procedures performed in studies involving animals were in accordance with the ethical standards of the institution or practice at which the studies were conducted.
- 3.Llovet JM, Bustamante J, Castells A, Vilana R, Ayuso Mdel C, Sala M, et al. Natural history of untreated nonsurgical hepatocellular carcinoma: rationale for the design and evaluation of therapeutic trials. Hepatology (Baltimore, Md). 1999;29(1):62–7. https://doi.org/10.1002/hep.510290145.CrossRefGoogle Scholar
- 4.Villa E, Moles A, Ferretti I, Buttafoco P, Grottola A, Del Buono M, et al. Natural history of inoperable hepatocellular carcinoma: estrogen receptors’ status in the tumor is the strongest prognostic factor for survival. Hepatology (Baltimore, Md). 2000;32(2):233–8. https://doi.org/10.1053/jhep.2000.9603.CrossRefGoogle Scholar
- 6.Cheng AL, Kang YK, Chen Z, Tsao CJ, Qin S, Kim JS, et al. Efficacy and safety of sorafenib in patients in the Asia-Pacific region with advanced hepatocellular carcinoma: a phase III randomised, double-blind, placebo-controlled trial. Lancet Oncol. 2009;10(1):25–34. https://doi.org/10.1016/s1470-2045(08)70285-7.CrossRefPubMedGoogle Scholar
- 7.Geschwind JF, Kudo M, Marrero JA, Venook AP, Chen XP, Bronowicki JP, et al. TACE Treatment in Patients with Sorafenib-treated Unresectable Hepatocellular Carcinoma in Clinical Practice: Final Analysis of GIDEON. Radiology. 2016;279(2):630–40. https://doi.org/10.1148/radiol.2015150667.CrossRefPubMedGoogle Scholar
- 8.Chao Y, Chung YH, Han G, Yoon JH, Yang J, Wang J, et al. The combination of transcatheter arterial chemoembolization and sorafenib is well tolerated and effective in Asian patients with hepatocellular carcinoma: final results of the START trial. Int J Cancer. 2015;136(6):1458–67. https://doi.org/10.1002/ijc.29126.CrossRefPubMedGoogle Scholar
- 10.Huang M, Lin Q, Wang H, Chen J, Bai M, Wang L, et al. Survival benefit of chemoembolization plus Iodine125 seed implantation in unresectable hepatitis B-related hepatocellular carcinoma with PVTT: a retrospective matched cohort study. Eur Radiol. 2016;26(10):3428–36. https://doi.org/10.1007/s00330-015-4198-x.CrossRefPubMedPubMedCentralGoogle Scholar
- 12.Lu J, Guo JH, Zhu HD, Zhu GY, Chen L, Teng GJ. Safety and efficacy of irradiation stent placement for malignant portal vein thrombus combined with transarterial chemoembolization for hepatocellular carcinoma: a single-center experience. JVIR. 2017;28(6):786–94.e3. https://doi.org/10.1016/j.jvir.2017.02.014.CrossRefPubMedGoogle Scholar
- 14.Luo J, Yan Z, Liu Q, Qu X, Wang J. Endovascular placement of iodine-125 seed strand and stent combined with chemoembolization for treatment of hepatocellular carcinoma with tumor thrombus in main portal vein. Journal of vascular and interventional radiology: JVIR. 2011;22(4):479–89. https://doi.org/10.1016/j.jvir.2010.11.029.CrossRefPubMedGoogle Scholar
- 15.Yang M, Fang Z, Yan Z, Luo J, Liu L, Zhang W, et al. Transarterial chemoembolisation (TACE) combined with endovascular implantation of an iodine-125 seed strand for the treatment of hepatocellular carcinoma with portal vein tumour thrombosis versus TACE alone: a two-arm, randomised clinical trial. J Cancer Res Clin Oncol. 2014;140(2):211–9. https://doi.org/10.1007/s00432-013-1568-0.CrossRefPubMedGoogle Scholar
- 16.Yu TZ, Zhang W, Liu QX, Li WH, Ma JQ, Zhang ZH, et al. Endovascular brachytherapy combined with portal vein stenting and transarterial chemoembolization improves overall survival of hepatocellular carcinoma patients with main portal vein tumor thrombus. Oncotarget. 2017;8(7):12108–19. https://doi.org/10.18632/oncotarget.14520.CrossRefPubMedPubMedCentralGoogle Scholar