Cancer Hospital & Institute, Chinese Academy of Medical Sciences Survival Benefit with IMRT Following Narrow-Margin Hepatectomy in Patients with Hepatocellular Carcinoma Close to Major Vessels Z. Wang, W. Wang, J. Wu, Y. Li Cancer Hospital & Institute, Chinese Academy of Medical Sciences

Background For patients with HCC close to major vessels, potential R1 resections occur frequently (Couinaud segments IV, V and VIII), (Couinaud segments II, III, VI and VII) Our study examines the prognostic significance of postoperative IMRT in patients with narrow-margin (<1.0 cm) hepatectomy

Methods Group A (n = 33) Group B (n = 83) Group C (n = 65) Inclusion criteria Without any neoadjuvant or adjuvant treatments except for postoperative IMRT Macroscopically complete tumor removal Preoperative Child–Pugh class A ECOG Performance Status ≤ 1 Absence of distant metastasis Group A (n = 33) narrow-margin (<1.0 cm) hepatectomy + IMRT surgeons have to carefully dissect and peel the tumor away from the vascular surface because the tumor has adhered to the vessels. Advances in surgical techniques and preoperative planning have led to the development of null-margin (no real resection margin) resections, a special type of R1 resection, where surgeons carefully dissect and peel the tumor away from the vascular surface (14, 15). Null-margin resections of centrally located liver lesions have been reported to be as safe as conventional R0 surgeries Group B (n = 83) narrow-margin hepatectomy alone Group C (n = 65) wide-margin (≥1.0 cm) hepatectomy

Results OS DFS ER (<18 months) Intrahepatic recurrence Extrahepatic recurrence Marginal Nodular Diffuse Group A* 89.1% 64.2% 18.2% 0.0% 30.3% 6.1% 9.1% Group B 67.7% 52.2% 43.4% 9.6% 13.3% 21.7% 20.5% Group C 86.0% 60.1% 16.9% 3.1% 20.0% 9.2% *No patient developed radiation-induced liver disease

Conclusions Postoperative IMRT following narrow-margin hepatectomy may be a favorable therapy for both its clinical benefit and safety profile Moreover, this treatment is equally effective as wide-margin hepatectomy