Hepatocellular carcinoma (HCC) is the fifth more common cancer in the world, with high mortality rates, due to the low number of patients who are eligible for therapy with curative intent, like surgical resection. Moreover, surgical resection is associated with a high risk of tumor recurrence, because of the tumor seeding through microscopic intrahepatic vessels that surround the tumor, the so-called "microvascular invasion".

To adequately deal with this phenomenon, the surgeon has to perform either an 'anatomical' liver resection, which remove not only the tumor but also the whole corresponding vascular network, or a 'tumorectomy' with resection margins of at least 2 cm. Unfortunately, these principles cannot always be achieved due to underlying liver cirrhosis that is present in more than 80% of patients.

Stereotactic body radiation therapy (SBRT) has been proven to efficiently necrotize or stabilize HCC nodules when surgery is not possible. Our hypothesis is that pre-treatment with SBRT prior to surgical resection of HCC might improve the results through the destruction of possible seeding in the peritumoral environment.

Given the novelty of this therapeutic strategy, it is necessary to verify its feasibility and safety, prior to test its efficacy in patients with HCC. The KARCHeR-1 study aims at making sure that preoperative SBRT would not result in important delays or serious adverse events such as to cancel the planned surgical resection, in patients who otherwise could have benefited from it. This issue is commonly called 'drop-out'. Thirty patients are expected to be included in the KARCHeR-1 study, which would be in favor of continuing to evaluate this therapeutic strategy if less than 3 drop-outs occur, and would be immediately discontinued if 3 drop-outs occur. Other outcomes will also been studied, like intraoperative issues, postoperative morbi-mortality, pathological features on the surgical specimen and its correlation with preoperative imaging, and finally, tumor recurrence and survival.

Inclusion Criteria:

• Biopsy-proven hepatocellular carcinoma or EASL/AASLD criteria
• Single nodule, 3 to 8 cm of largest diameter
• Hepatocellular carcinoma eligible for conventional liver resection with curative intent (R0), without preoperative portal vein embolization

Exclusion Criteria:

• Performance status > 2
• Severe comorbidity with contraindication for either surgery or radiation therapy
• Decompensated liver cirrhosis (Child-Pugh B or C)
• Neoplastic portal vein thrombosis or extra-hepatic metastases
• Previous anticancer therapy within the last 5 years