Sick British boy arrives for treatment in Prague from Spain

(Adds boy arriving, comments from doctors)

PRAGUE, Sept 8 (Reuters) - A British boy with a brain tumour, whose parents were briefly arrested in Spain when seeking alternative care, arrived at a Prague hospital for treatment on Monday.

Ashya King's parents took him from a hospital in southern England against medical advice at the end of August and left the country, triggering a manhunt that drew widespread condemnation in the British media of the police's pursuit of the couple.

The couple were detained in Spain, separated from their five-year-old son and then released days later by a Spanish judge. They said they wanted to take him to hospital in Prague that offered proton radiation therapy.

The boy arrived with his parents at Prague's Motol Hospital, one of the EU member country's top health facilities, on Monday afternoon, a Reuters cameraman on the scene said.

He is due to receive a series of 30 sessions of proton beam radiotherapy under full anaesthesia at the newly built Proton Therapy Center (PTC (NasdaqGS: PTC - news) ) across town.

"Under the optimum scenario, he will undergo examination in the proton centre tomorrow, radiotherapy will be planned, and started next week," Jan Stary, head of the child haematology and oncology clinic in Motol, said before the family arrived.

Doctors first had to make sure the cancer had not spread through the spine before confirming the treatment plan, he said. They have been in touch with British and Spanish colleagues, he said.

The centre specialises in a type of radiological cancer treatment used for certain types of tumours, which doctors there say has fewer undesirable side effects than some other treatments.

Ashya's family have said they left England because they wanted him to receive a different type of treatment, prompting questions about whether the British police overreacted in launching a Europe-wide manhunt. (Reporting by Jan Lopatka and Jiri Skacel; Editing by Andrew Heavens and Sonya Hepinstall)