Advice on radiation treatments- matt just had liver resection

Matt had liver resection surgery in Dec to remove several lesions. He did great! We went back to see our oncologists this past week & he is talking with our colon & liver drs about what is next. We go back next week to discuss & get bloodwork results. I feel like everything is going so fast. DX in May 2010, did chemotherapy for 5 months & tumors had a great response with chemotherpay & Dr said also pathology good too. I know he will have to have radiation but i have heard some about gamma knife- is this used to treat colorectal cancer? I have read radation could produce negative results later such as secondary cancers? just wanted to know about others experiences & the treatment you may have had.

Any advice is greatly appreciated!!! Colorectal cancer metastised to his liver, numerous tumors removed & 2 tumors had Radio Frequency Ablation. Still has primary tumor.

DX May 2010
5 Months FoLFOX
Liver resection 12/17/10