The court of appeal has upheld the right of a 12-year-old boy to refuse treatment for cancer even though doctors say it will improve his survival chances.

Judges ruled that the boy, identified only as David, was capable of making a rational decision not to undergo chemotherapy for a brain tumour, after hearing evidence from a psychiatrist.

His father had brought the case against care organisation De Jeugd & Gezinsbeschermers, arguing that David might have been influenced by his mother’s belief in alternative medicine. The parents are divorced.

David’s tumour was removed last year and the operation was followed by six weeks of radiotherapy. He was due to begin a five-week course of chemotherapy in March, but declined because of the risk of side-effects.

Documents produced in court said that his chances of survival were estimated to be 75% to 80% if the chemotherapy went ahead, but only 50% without it.

The district court in Alkmaar ruled in May that he could not be forced to undergo the treatment. His father appealed against the decision, but judges in Amsterdam agreed with the lower court.