Would you recommend radiation or chemoradiation in a patient with cholangiocarcinoma s/p surgery and adjuvant treatment with single hepatic metastasis 3 years later?

Challenging case and worthy of tumor board discussion. I would likely start systemic therapy, and if response, consider regional therapy with resection or SBRT, assuming the hepatic function is adequate (keep in mind, TARE can cause liver disease). I have one patient in a similar situation, now > 5 years out and NED after resection of initially unresectable cholangio. Ablative procedures such as repeat catheter-based therapy and even SBRT have a risk of hepatic abscess after the Whipple procedure, given the hepaticojejunostomy. Can be done but has to be done carefully...

Considering post-TARE dosimetry using PET imaging to see the dose to the tumor and uninvolved liver, there are several software programs doing this, including MIM. Often, TARE delivers a non-uniform dose to the large liver tumor. One then generates a treatment plan for proton (or carbon, not available in the US as of now) beam therapy, preferably IMPT, depending on the underlying liver reserve (Child-Pugh score) and tumor location, one can deliver a reasonable dose to the active tumor area while sparing the uninvolved liver. Use NRG GI-003 for set-up and planning.

Oshiro et al., PMID 28366501