SINGAPORE - Ms Leong Pei Ying, 41, is grateful that proton beam therapy (PBT) is now available in Singapore, and is covered by her Integrated Shield Plan (IP).
The hospital clinical administrator has had her skull opened five times since she was diagnosed with a brain tumour in her frontal lobe 11 years ago, when she was 30 years old.
The operations in 2013, 2016, 2019, 2021 and 2024 were to cut out as much of the cancer tumour as possible. But each time after surgery, the tumour grew again.
She is hoping that having undergone PBT together with chemotherapy – to shrink the tumour following her surgery earlier in 2024 – her frequent dates with the operating theatre would be a thing of the past. Previously, she did not follow up on the surgical excision of the tumour with chemotherapy and radiation, which she declined as conventional X-ray may severely damage parts of her healthy brain cells.
“My doctor suggested whole-brain radiation,” she said. “When I asked about side effects, he said it might affect my mental capacity, make me forgetful, and as it (the tumour) was just behind my right eye, it could also affect my vision. The risk was too high.”
In March, she went for PBT treatment, which comprised 33 daily sessions, each lasting a few minutes.
“The prognosis for her is good,” said her radiation oncologist, Dr Looi Wen Shen. Before the PBT treatment, the pace of disease progression was picking up and the tumour was growing, so she had surgery to reduce the size of the tumour in January.
Said Dr Looi: “Following PBT, the tumour progression halted, with some slight shrinkage. We don’t expect her type of tumour to have a complete response right away as PBT’s effects on the tumour may take some time. Although some tumour cells may die right away, some cells may only die when they attempt to replicate.”
Dr Michael Wang, who chairs radiation oncology at the National Cancer Centre Singapore (NCCS), said the therapy is an advanced form of radiation treatment that can target cancer tumours with greater precision and minimise damage to surrounding tissues and organs.
The risks of damaging healthy cells are far lower with PBT.
In conventional radiation, the rays start strong and diminish as they move from outside the body, through the tumour and out the opposite side. This means that healthy cells in the path of the rays may get affected.
With PBT, the rays start at a low dose, spike at the tumour and stops, without going further. So there may be damage to healthy cells from the point of entry to the tumour, but not beyond that. Also, the strength of the rays is lower on entry and peaks at the tumour.
Singapore is the second country in South-east Asia to offer PBT. The other is Thailand, but treatment there is exclusively for Thai nationals.
Singapore’s first PBT centre opened at Mount Elizabeth Novena in May 2023. Two more opened one month later at the Singapore Institute of Advanced Medicine Holdings (SAM) at Biopolis, and NCCS.
Mount Elizabeth Novena and SAM have one PBT treatment gantry each, while NCCS has four treatment gantries. The rotating gantries are the treatment arms of the machine, with each located in a separate room.
Since the launch of PBT here, more than 300 people have undergone treatment.
Dr Wang said PBT “potentially causes fewer treatment-related side effects and reduces the risk of developing secondary cancers due to radiation. It is recommended for young adults and children below the age of 25. Proton therapy is also suitable for cancers located in sensitive areas like the brain, or near the eye or spinal cord”.
He added that at NCCS, “the top three cancers that were treated using proton therapy to date are head and neck cancer, prostate cancer, as well as cancers of the nervous system and musculoskeletal system arising in children, adolescents and young adults”.
Ms Leong said she had thought of going to the US for the treatment, but this would not have been covered by insurance and she found the cost prohibitive. Aside from the cost of the therapy, she would also need to be there for over a month as the treatment is done in more than 30 short doses daily.
Her bill of $67,000 for undergoing the therapy at SAM was almost entirely covered by her IP and rider.
The Ministry of Health (MOH) has limited the use of PBT to certain cancers, largely because the treatment costs 2½ to three times that of conventional radiation, and, for most cancers, it does not increase survival rates.
Claims from MediShield Life must also meet certain criteria, such as “an expected survival of more than five years (for the patient) after treatment with PBT”.
Coverage under the IPs varies. The current maximum coverage is $100,000.
The majority of PBT patients here are locals.
The NCCS has had 164 patients, of whom 151 were Singaporeans or permanent residents. Its spokesperson said locals paid from S$28,600 to S$50,000, depending on the number of treatment sessions needed.
The spokesperson added: “About 87 per cent of these patients have had their treatment cost covered by Integrated Shield Plans or MediFund, after MediSave and MediShield Life.”
At Mount Elizabeth Novena, more than 110 patients have been treated, of whom 52 per cent were locals. Its spokesman said the rest were foreign patients coming “from 16 countries, mainly Malaysia, Indonesia, the Philippines, Vietnam, and also countries farther away like the UK, Canada, Bhutan and Kenya”.
SAM did not want to reveal how many patients it has treated, but said 60 per cent of them were locals. Said its chief operating officer Paul Yeo: “Foreign patients were mainly from Australia, Vietnam and Indonesia, but we had patients from all over, even Nepalese.”
MOH said there is no subsidy for PBT as it is a non-standard treatment option. Its spokesman added: “MOH will review the financing approach for proton beam therapy when there is sufficient data and evidence of its cost-effectiveness.”
Said Ms Leong: “I hope that with the PBT treatment, I no longer need to go for surgery every few years.”
