Intercepting radiotherapy using a real-time tumor-tracking radiotherapy system for highly selected patients with hepatocellular carcinoma unresectable with other modalities.
OBJECTIVE
To assess the clinical outcome of intercepting radiotherapy, in which radiotherapy is delivered only when a tumor in motion enters a target area, using a real-time tumor-tracking radiotherapy (RTRT) system for patients with hepatocellular carcinoma who were untreatable with other modalities because the tumors were adjacent to crucial organs or located too deep beneath the skin surface.


METHODS
Eighteen tumors, with a mean diameter of 36 mm, were studied in 15 patients. All tumors were treated on a hypofractionated schedule with a tight margin for setup and organ motion using a 2.0-mm fiducial marker in the liver and the RTRT system. The most commonly used dose of radiotherapy was 48 Gy in 8 fractions. Sixteen lesions were treated with a BED(10) of 60 Gy or more (median, 76.8 Gy).


RESULTS
With a mean follow-up period of 20 months (range, 3-57 months), the overall survival rate was 39% at 2 years after RTRT. The 2-year local control rate was 83% for initial RTRT but was 92% after allowance for reirradiation using RTRT, with a Grade 3 transient gastric ulcer in 1 patient and Grade 3 transient increases of aspartate amino transaminase in 2 patients.


CONCLUSIONS
Intercepting radiotherapy using RTRT provided effective focal high doses to liver tumors. Because the fiducial markers for RTRT need not be implanted into the tumor itself, RTRT can be applied to hepatocellular carcinoma in patients who are not candidates for other surgical or nonsurgical treatments.
Taguchi
Hiroshi
H
Department of Radiology, Hokkaido University School of Medicine, Sapporo, Japan. thiroshi@radi.med.hokudai.ac.jp
Sakuhara
Yusuke
Y
Hige
Shuhei
S
Kitamura
Kei
K
Osaka
Yasuhiro
Y
Abo
Daisuke
D
Uchida
Daichi
D
Sawada
Akihiro
A
Kamiyama
Toshiya
T
Shimizu
Tadashi
T
Shirato
Hiroki
H
Miyasaka
Kazuo
K
D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D016461:Chemoembolization, Therapeutic; D003199:Computer Systems; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008099:Liver; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009068:Movement; D011859:Radiography; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012189:Retrospective Studies; D015996:Survival Rate