headaches after chemo

i posted in the resection column about my sister and thought i would just add it to this discussion as well. i was wondering if anyone had any information on this. my sister juv finished her 8 month battle with resection surgery followed by chemo. since she finished her chemo she has been getting awful headaches. she went for the scan of her liver and there was no evidence of recurrence in the area where her tumor was removed. they are now ordering a head scan to see if maybe the cancer spread to her brain or if there is some other explanation for the headaches. i have found no articles saying that cc spreads to the brain or anything about headaches after chemo. does anyone have any insight on this topic. thank you very much.