Abstract: Objective To study the treatment plan for huge and small primary liver cancer treated by stereotactic radiotherapy. Methods The patients with primary liver cancer were treated with γ-ray stereotatic radiotherapy（SRT）. 43 patients in group A，their planning target volume was no less than 300cm3（vptv≥300cm3）； 28 patients with 31 targets in group B，their planning target volume was no more than 100 cm3（vptv≤100cm3）； Results In group A，PTVs were surrounded by 50％～55％ isodose curve，the minimum dose of 3200～3900cGy were delivered to PTVs with the fraction dose of 300～350cGy，14～22 fields were needed in each treatment plan，and the index of dose homogeneity of target was 1.60～1.72；In group B，PTVs were surrounded by 70％～90％ isodose curve，the minimum dose of 4000～5400cGy were delivered to PTVs with the fraction dose of 400～600cGy，3 fields were needed at most in each treatment plan，and the index of dose homogeneity of target was 1.06～1.43；There was no normal tissue that couldn't tolerate the irradiation in the two groups. Conclusions Qualified treatment plan for both huge and small primary liver cancer treated by γ-ray stereotactic radiotherapy could be designed，but much more fields are needed in huge liver cancer than in small liver cancer. Dose in small liver cancer is more homogeneous than in huge liver cancer.

Key words: Liver cancer, Stereotactic radiotherapy, Treatment plan