Falmouth toddler Theo Ward is back home after undergoing pioneering proton beam therapy in Florida but his family have to wait possibly for years to know whether the treatment has been successful in obliterating the youngster's tumour.

Theo, aged two, was accompanied to America by his parents, Lisa and James, and his big sister Evie-Mai, who spent almost eight weeks living in an apartment while the youngster spent up to three hours a day in hospital, almost every day of their trip.

The NHS funded the proton beam treatment after it was discovered that Theo had a rare form of cancer, Embryonal rhabdomyosarcoma, which affects fewer than 60 children a year. A tumour had developed behind his left eye which is inoperable so the treatment in Florida was deemed his best chance of beating the disease.

Theo has been enduring regular chemotherapy sessions over the past year, which continued in Florida alongside the new treatment. After a couple of days to settle in, Theo had MRI and CT scans and a mask was made which the toddler had to wear during the treatment which showed exactly where to direct the proton beams.

"The treatment was quite intensive, but he was so good," said Lisa. "He had 27 general anaesthetics while we were there, 25 for the proton therapy - one every week day - and two for the scans. The proton treatment only took about ten minutes, but he would be in hospital for two to three hours every time.

"His eye went really red and is very sensitive, just like an intense sunburn, which is all part of it and we were completely prepared for that. Luckily he was not sick or anything, he handled it really well and it just became normal for him."

While James took Theo to the hospital, Lisa stayed at the apartment and home-schooled Evie-Mai using work emailed by her new teacher at Marlborough School. Then, later in the evenings, because Theo has to stay out of direct sunlight, the entire family would go out to enjoy themselves.

"The proton centre got us tickets for pretty much everything," said Lisa. "They wanted us to have as much fun as possible while we were there and we do have some amazing memories." They went to the zoo twice, watched an American football game and met one of its stars, Zane Beadles, enjoyed Walt Disney World and several trips to the beach.

Now back home, the family have to play the waiting game. "It will be at least a year until we know if it has worked," said Lisa, "it could even be a number of years. "We were told the chance of Theo having vision in that eye is unlikely, but we don't know that yet either.

"Theo has to finish his chemotherapy, he has to have another three or four rounds, and then it will be just a case of surveillance. The hope is that therapy has blasted it (the tumour) and killed it off. They have told us not to judge anything but we are always going to have the worry. America wants to see Theo every couple of years to monitor things.

"We are just all looking forward to getting back to some sort of normality in the new year once Theo has had his Hickman line removed. We are hopeful that everything will be OK, that's all we can be."