Hi Cheryl,
I can't say I'm familiar with the G4 upgrade but , based on the news release, I believe it is an enhancement to the CK's ability to better treat extracranial lesions. While it isn't necessarily of relevance to folks who read this board, the real value of the CK is it's capability to provide a radiaosurgical option for people with tumors elsewhere in the body. Historically, radiosurgery has been an option limited to intracranial tumors such as AN's. This is essentially what the GK started out doing and is limited to today given targeting limitations. The skull provides a fixed frame of reference for radiosurgical machines whereas tumors in the rest of the body don't have that. This has limited patients with prostrate, lung, breast , pancreas etc, tumors only the options of surgery or radiation therapy which involves affecting a wide range of healthy tissue around the tumor and consequently a protocol of very low dose over many days. CK has a targeting capability to follow tumors as they move through breathing and provide the high dose required safely.
Probably more than you wanted to know about CK
, but I beleive the G4 is enhancing that capability which has no effect on CK's intracranial capability to treat an AN
Mark