Postoperative radiotherapy dose correlates with locoregional control in patients with extra-hepatic bile duct cancer.
OBJECTIVE
To evaluate the results of postoperative radiotherapy in patients with extra-hepatic bile duct cancer (EHBDC) and identify the prognostic factors for local control and survival.


METHODS
Between January 2001 and December 2010, we retrospectively reviewed the cases of 70 patients with EHBDC who had undergone curative resection and received postoperative radiotherapy. The median radiation dose was 50.4 Gy (range, 41.4 to 54 Gy). The resection margin status was R0 in 30 patients (42.9%), R1 in 25 patients (35.7%), and R2 in 15 patients (21.4%).


RESULTS
The 5-year rates of overall survival (OS), event-free survival (EFS), and locoregional control (LRC) for all patients were 42.9%, 38.3%, and 61.2%, respectively. The major pattern of failure was distant relapses (33 patients, 47.1%). A multivariate analysis showed that the postradiotherapy CA19-9 level, radiation dose (≥50 Gy), R2 resection margins, perineural invasion, and T stage were the significant prognostic factors for OS, EFS, and LRC. OS was not significantly different between the patients receiving R0 and R1 resections, but was significantly lower among those receiving R2 resection (54.6%, 56.1%, and 7.1% for R0, R1, and R2 resections, respectively).


CONCLUSIONS
In patients with EHBDC who had undergone curative resection, a postoperative radiotherapy dose less than 50 Gy was suboptimal for OS and LRC. Higher radiation doses may be needed to obtain better LRC. Further investigation of novel therapy or palliative treatment should be considered for patients receiving R2 resection.
Department of Radiation Oncology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Jung Ho
JH
Im
Department of Radiation Oncology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Jinsil
J
Seong
Department of Radiation Oncology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Jeongshim
J
Lee
Department of Radiation Oncology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Yong Bae
YB
Kim
Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Ik Jae
IJ
Lee
Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Jun Sung
JS
Park
Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Dong Sup
DS
Yoon
Department of Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Kyung Sik
KS
Kim
Department of Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Woo Jung
WJ
Lee
Adjuvant radiotherapy; Bile duct neoplasms; Radiotherapy dosage