Seven-year-old Neon Roberts is making "good progress" following his treatment, his father has said.
Late last year, Neon's mother Sally, failed in a legal bid to stop her son having radiotherapy for a brain tumour.
The High Court ruled that Neon should undergo radiotherapy for the cancerous tumour against her wishes.
Neon's father Ben - who is separated from Ms Roberts - said his son had completed the course of radiotherapy as planned.
Neon Roberts is "as sharp as ever" after his cancer surgery, which took place despite his mother's objections following a court ruling, reports the Daily Mail.
The seven-year-old's mother Sally Roberts wanted any operation on her son Neon delayed because she wanted opinions from doctors in Russia, Germany and the US but the Judge who assessed the evidence said the gains of going ahead with surgery outweighed the risks.
The Daily Mail reports that Neon woke up following the seven-hour procedure telling nurses: "I can still talk, you know."
Today Neon's mother will renew her fight at the High Court today over planned radiotherapy for her son. Ms Roberts claims the therapy will cause Neon long-term harm.
But doctors say he might die within months without it.
A seven year old boy from Devon is due to have surgery today for his brain tumour - against the wishes of his mother.
Sally Roberts ran away with her son Neon to stop him having treatment. But a High Court judge agreed with medical experts that he needed urgent surgery.
Mr Justice Bodey ruled today that Neon Roberts can undergo surgery on a "residual tumour" but it is not yet clear whether he can receive radiotherapy.
The ruling in the Family Division of the High Court was due to decide whether Neon should undergo radiotherapy treatment following surgery, against the wishes of his mother.
That issue was put to one side to deal with the more pressing decision regarding his operation.
A mother who disappeared with her young son to stop him being treated for cancer says she had no choice.
37-year-old Sally Roberts disappeared from her home in Tiverton with seven year old Neon because she was worried that radiotherapy would be damaging.
She says she needs more evidence that treatment is necessary and other options need to be explored. The case was heard at the High Court and a judge will make a decision next week. Sally spoke exclusively to Daybreak this morning. This is the full interview.