Could you advise what alternative treatments are there for a grade 4 glioblastoma brain tumor ?

Not many: Thus far, alternative therapy for gbm (grade IV glioma) has been extremely ineffective. I've had a few patients try other treatments over the years with disastrous results. The best treatment for gbm is to stick with proven methods. Vitamins, calcium, alkalinizing the blood, herbal therapy, etc all sound good but don't work at all. I hope this helps and wish you the best.

Many but not good: There are many proposed so called alternative treatments for brain tumors and not one has been shown to help a patient in any convincing fashion. If you have a brain tumor you absolutely should work with a physician(s) experienced in the treatment of these tumors. Furthermore, although some alternative treatments are harmless, some are not--and their use should also be discussed with your doctor.