This is true... it gets your circulation going and motivates your lymph system too. Since you didn't have surgery david likely you're nodes are not nearly as bad as someone who has had a neck dissection (though admittedly radiation does it's own special brand of damage - when surgery is involved the drainage path is destroyed/disrupted/nonexistent - in the surgical area, so exercise will help a little - but not as much as lymphatic massage that works force the fluid to make new pathways).

That said. I would want a certain amount of time and a certain number of clear scans to pass before beginning lymphatic massage - the lymphatic system runs parallel to your circulatory system - it works to clean your blood, so it had access to everywhere. If there is any cancer left, you do not want to be sending it off to distant areas.

hugs.