Abstract: Objective To study the designing of treatment plan for huge primary liver cancer treated by γ-ray stereotactic radiotherapy. Methods 37 patients with huge primary liver cancer were treated with γ-ray stereotatic radiotherapy（SRT）. Each planning target volume was more than 300 cm3（vptv≥300cm3）. The dose of 3200～3900cGy were delivered to PTVs with the fraction dose of 300～350cGy and 6 consecutive fractions per week. The planning targets were all surrounded by 50％～55％ isodose curve. 14～22 isocenters were needed in each treatment plan in order to cover the PTV by 50％～55％ isodose curve. The index of dose homogeneity of target was 1.60～1.72. There was no normal tissue that couldn’t tolerate the irradiation involved. Results All patients were examined with image of CT or MRI. The total effective rate（CR＋PR），steady disease（SD），progressive disease（PD）was 78.4％，8.1％ and 13.5％，respectively. The main gastrointestinal complications were uncomfortable upper abdomen and poor appetite. Conclusions Qualified treatment plan for huge primary liver cancer treated by γ-ray stereotactic radiotherapy could be designed，but lots of isocenters were needed in the treatment plan and the dose in the target was not homogeneous.

Key words: Hepatoma, Treatment plan, Stereotactic radiotherapy