- A team of experts identified specific cases in which proton beam therapy (PBT) may offer more benefit than X-ray therapy (XRT) in liver cancer.
Why this matters
- There is little consensus on how to select liver cancer patients for PBT.
- A primary reason to use PBT is to spare uninvolved liver.
- PBT may be best for patients who are likely to have a suboptimal therapeutic ratio from XRT.
- There was consensus that PBT may be advantageous over XRT in hepatocellular carcinoma (HCC) patients with:
- At least CP-B cirrhosis.
- High tumor-to-liver ratio.
- Larger tumor size.
- Smaller uninvolved liver volume.
- Higher number of tumors.
- Prior radiation therapy to the liver.
- There were no consensus thresholds for the above characteristics.
- PBT may benefit unresectable intrahepatic cholangiocarcinoma (IHC) or metastatic liver disease because ablative level tumor dose escalation may not be possible with XRT given liver constraints in some patients with large or more numerous lesions.
- 70% of experts felt that PBT is reasonable for liver metastasis, and 93% believed it was reasonable for unresectable nonmetastatic IHC.
- PBT should be considered for curative intent treatment for liver-only or liver-dominant disease.