Failure patterns after curative resection for intrahepatic cholangiocarcinoma: possible implications for postoperative radiotherapy.

High proportion of the recurrences occurred only inside the potential PORT volume, implying adjuvant radiotherapy might improve the local-regional control. Surgical margins and lymph node stations No.16a2, 9, 8, 12, 13, and 14 are suggested to be included in the radiation volume.