My Mom had a lymph node removed, and a biopsy done 5 years ago, She had lymphoma and went through chemo. It was a difficult time, but I believe that God worked through that situation to bring me closer to him. It was a hard fight for her, and for the whole family. But she is now cancer free, and has been for the last 4 years. Her lymphoma was stage 3, and was in most of the lymphnodes in her stomach, neck, groin, underarms, pretty much ALL of them. She goes in now every 6 months for a CT scan, you are right the PET scans shows alot. I pray that he doesn't need chemo, but if he does, take notes at the doctors office, I am thankful I did, as mom's kidney's failed 2 days after her first chemo treatment, and they had to do dialysis. She was in the hospital for a week and lost 20 pounds. This was because she need a drug to help the dying cancer cells leave her body. they collected in her kidney's and crystilized causing them to shut down. I am not trying to scare you, just to let you know that YES prayer is answered, Mom is doing GREAT. I will pray for your family. Your situation is very close to my heart.
God Bless you all.
Mariarae