My Dad Has Had His Prostate Removed 7years His Psa

My dad has had his prostate removed 7years his psa has been up and down has gone from a psa count of 550 to 1100. in one month, he has had trial pills,harmone shots in the stomach and now they told him he has spots on his bones and glans?? and now he has to go on CHEMOTHERAPY is this normal and will he be ok he is 73years old and otherwise very healthy has not had any weight loss and has been feeling tired just recently. I am very concerned but the doctors have kept on top of this and his bone scans and CT scans have shown nothing up untill now. I hope chemo will help ,