MELBOURNE, Australia Sebastian Selo, a nine-year-old English boy brought to Melbourne two weeks ago for surgery pioneered here, will have his operation on Tuesday, AFP reported on Monday.

The world-first treatment developed by Dr. Jeffrey Rosenfeld aims to reduce the number of seizures suffered by Sebastian, who has a rare tumor known as hypothalamic hamartoma (HH).

A spokeswoman at the Royal Children's Hospital said a series of medical tests undertaken on Sebastian in the past week had revealed no complications in the lead-up to surgery.

"He is scheduled for surgery tomorrow afternoon and everything is fine with him at this point," she said Monday.

The tumor has affected the part of Sebastian's brain that controls his emotions and appetite, and causes him to suffer massive brain seizures daily, leaving him unable to speak.

The operation will involve incisions from the top of the brain rather than the base, avoiding nerves and arteries and lessening the danger of a stroke occurring.

"Doctors say there is a 50-70 percent chance that Sebastian will be completely seizure-free," the spokeswoman said.

Dr. Simon Harvey, from the Royal Children's Hospital's Epilepsy Program, recently said the technique had been used during the last three years to treat 18 children, 11 of whom were now totally free of seizures.

Five had improved dramatically, and two patients showed a moderate improvement, Harvey said. None was worse off as a result of the treatment.

Harvey said the surgical team would remove the tumor with an "ultra sonic aspirator", using high frequency sound-waves.

Sebastian will remain in Melbourne for a month of observation and further tests after the operation, which, if all goes well, will last between five and six hours.

Sebastian's parents Louie and Anna Selo raised 40,000 pounds (U.S.$57.000) to pay for the flight and medical treatment.