가톨릭의대 / 이소정, 김명수*
Abstract
Purpose: This study aims to evaluate the efficacy, feasibility, and safety of the magnetic resonance imaging (MRI)-guided tumor tracking hypofractionated radiotherapy (HFRT) and stereotactic body radiation therapy (SBRT) for portal vein tumor thrombus (PVTT) in hepatocellular carcinoma (HCC) patients.
Methods: We retrospectively reviewed the twelve cases of unresectable HCC with tumor thrombus in the main trunk or first branch of the portal vein that were treated with MRI-guided tumor tracking HFRT or SBRT using the ViewRay Linac MRIdian system between June 2019 and January 2021. The HFRT was performed with a total of 50 Gy in 10 fractions, and SBRT performed in a range of 36-50 Gy with 4-5 fractions. The median biologic effective dose (BED) with an a/b ratio of 10 was 75 Gy10 (range 68.4-100 Gy10).
Results: The median follow-up duration was 5.0 months (range 1.9-12.8 months). Ten patients (83.3%) showed an objective response of PVTT. At the time of analysis, ten patients (83.3%) showed local control. The 1-year intrahepatic control rate was 48.9%. Three patients (25%) showed mild gastrointestinal symptoms, and there were no cases of grade 3 or higher toxicity. For hepatic toxicity, there were no cases in which the Child-Pugh score increased by more than two points after RT without disease progression.
Conclusion: MRI-guided tumor tracking HFRT and SBRT was a feasible, effective, and safe treatment option in HCC patients with tumor thrombi in the main trunk or first branch of the portal vein.
MRI-guided real time tumor tracking and gating
종양을 실시간 MR imaging을 통해 추적하여, 설정한 boundary (GTV에서5mm margin)을 3%이상 벗어날 경우, 자동으로 beam이 off 되는 방식을 통해, 종양부에서 최소한의 margin으로도 효과적 방사선 치료를 시행할 수 있음
Affiliations
So Jung Lee 1, Myungsoo Kim 2, Yoo-Kang Kwak 1, Hye Jin Kang 1
1Department of Radiation Oncology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
2Department of Radiation Oncology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. mskim0710@gmail.com.