The NHS is to pay for five-year-old brain tumour patient Ashya King's proton beam therapy treatment in the Czech Republic.
His parents Brett and Naghemeh King sparked an international police hunt after they took their son out of Southampton General Hospital and travelled to Prague for the treatment which was not available for him on the NHS.
David Cameron has said "common sense in the end won out" after five-year-old Ashya King was finally reunited with his parents.
Speaking on Good Morning Britain, the Prime Minister said: "Having had a disabled child often in hospital, often fed through a tube those pictures absolutely meant so much to me.
"The thought of having your much-loved boy separated from you for all those hours and days I can't think of anything more painful for a parent."
Ashya King's parents told the Daily Mail they fled the UK after being told NHS treatments would leave him with life-long disabilities.
The head of the police force which applied for a European Arrest warrant against the parents of Ashya King has now urged their release.
A British mother whose son's life was saved by proton therapy has told ITV that she defied NHS doctors' advice to pursue the treatment.