The Headline: Protons are no better than photons in treating hepatocellular carcinoma.
The Study: Does proton dosimetry actually translate to better clinical outcomes compared with photons? In GI003, this long standing question was applied to the liver. It included 115 patients with unresectable or locally recurrent HCC who were randomized to receive proton therapy or photon therapy. In both arms, dose fractionation (30-50 Gy in 5 fractions or 37.5-67.5 Gy in 15 fractions) was individualized based on mean liver dose. At 24 months, protons did not significantly increase OS (56.2% v 69.3%), PFS (31.6% v 30.4%), or local progression (19.8% v 22.3%). The rate of grade 3+ adverse effects were numerically lower with protons (11% v 24%).
TBL: In GI003, proton therapy failed to significantly improve clinical outcomes or significantly reduce adverse effects for patients with HCC. | Hong, ASTRO 2026
The Study: Does proton dosimetry actually translate to better clinical outcomes compared with photons? In GI003, this long standing question was applied to the liver. It included 115 patients with unresectable or locally recurrent HCC who were randomized to receive proton therapy or photon therapy. In both arms, dose fractionation (30-50 Gy in 5 fractions or 37.5-67.5 Gy in 15 fractions) was individualized based on mean liver dose. At 24 months, protons did not significantly increase OS (56.2% v 69.3%), PFS (31.6% v 30.4%), or local progression (19.8% v 22.3%). The rate of grade 3+ adverse effects were numerically lower with protons (11% v 24%).
TBL: In GI003, proton therapy failed to significantly improve clinical outcomes or significantly reduce adverse effects for patients with HCC. | Hong, ASTRO 2026