Right hepatectomy is most appropriate for this patient who underwent primary resection for stage II colon cancer 3 years ago and now has three new liver lesions in a surgically resectable pattern. The role of monitoring patients after initial resection is to detect recurrent, surgically curable tumors, such as oligometastatic liver or lung metastases, and monitor for the development of new primary cancer. Monitoring typically includes a physical examination and measurement of serum carcinoembryonic antigen levels every 3 to 6 months for the first 3 years and every 6 months during years 4 and 5. Surveillance CT scans of the chest and abdomen are recommended annually for at least the first 3 years postoperatively. This patient has oligometastatic disease that is potentially curable by surgical resection and should undergo right hepatectomy.

A needle biopsy is not indicated. The clinical presentation is so strongly indicative of metastatic colorectal cancer that a negative needle biopsy would not exclude the diagnosis of cancer and would therefore not alter management. Surgical resection would be warranted regardless of the biopsy results.

Hepatic artery embolization is a palliative technique used to treat patients with more vascular tumors, such as hepatocellular carcinoma and neuroendocrine tumors. It is not routinely used for treatment of metastatic colorectal cancer and would not be an appropriate consideration when a potentially curative alternative such as surgery is available.

Given that this patient's liver metastases are potentially curable, palliative chemotherapy is not indicated.

Radiation therapy is not routinely used to treat liver metastases and would also not be an appropriate consideration for a patient who is a candidate for potentially curative surgery.