title: Clinical assessment of coiled fiducial markers as internal surrogates for hepatocellular carcinomas during gated stereotactic body radiotherapy with a real-time tumor-tracking system.
abstract: To report the clinical usefulness of coiled fiducial markers as an internal surrogate in gated stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) using a real-time tumor-tracking radiotherapy (RTRT) system.
  
  
  
  Seventeen HCC patients with Child-Pugh (CP) scores of A or B received gated SBRT (45-50Gy in 5-10 fractions) using an RTRT system and Visicoil markers. Local control (LC), progression-free (PFS), and overall survival (OS) rates were assessed using the Kaplan-Meier method. Toxicities were assessed using the Common Terminology Criteria for Adverse Events, Version 4.0.
  
  
  
  Of the 17 patients, 14 had a CP score A. The mean planning target volume was 54.6cc. Only 1 patient developed pneumothorax after marker implantation. Visicoil tracking during SBRT was possible in all cases. With a median follow-up of 16months, 1-year LC, PFS, and OS rates were 100%, 53%, and 82%, respectively. Grade≥2 late toxicity was observed in 2 patients (grade 2 duodenal ulcer and grade 3 temporary transaminase elevation).
  
  
  
  Using an RTRT system and Visicoil markers, gated SBRT was well tolerated in patients with HCC. This can be considered a safe treatment strategy with potential for delivering favorable outcomes.
authors.affiliation: Department of Radiation Oncology, Yamaguchi University Graduate School of Medicine, Japan. Electronic address: hhana@yamaguchi-u.ac.jpn.
authors.forename: Hideki
authors.initials: H
authors.lastname: Hanazawa
authors.affiliation: Department of Radiation Oncology, Yamaguchi University Graduate School of Medicine, Japan.
authors.forename: Shotaro
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Radiation Oncology, Yamaguchi University Graduate School of Medicine, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Shiinoki
authors.affiliation: Department of Radiation Oncology, Yamaguchi University Graduate School of Medicine, Japan.
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Yamaguchi University Graduate School of Medicine, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yuasa
authors.affiliation: Department of Radiological Technology, Yamaguchi University Hospital, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Koike
authors.affiliation: Department of Radiological Technology, Yamaguchi University Hospital, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawamura
authors.affiliation: Department of Radiation Oncology, Yamaguchi University Graduate School of Medicine, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Shibuya
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000532:radiotherapy*; D003199:Computer Systems; D005260:Female; D057918:Fiducial Markers; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D015996:Survival Rate
keywords: Hepatocellular carcinomas; Radiotherapy; Real-time tumor-tracking radiotherapy system; Visicoil markers