Ultrasound procedure for liver cancer saves grandfather’s place on transplant waiting list

12 Jun 2026 | The Straits Times

SINGAPORE – Mahamood Ahamed, a grandfather of 12, almost had to give up his place on the waiting list for a liver transplant.

The 69-year-old was diagnosed with end-stage liver disease late in 2025.

Doctors also found a 1.6cm cancerous tumour that could have disqualified him from a liver transplant.

But he found hope in a clinical trial that uses focused ultrasound energy to destroy tumours non-invasively.

In the procedure called histotripsy, ultrasound is used to deliver high-pressure vibrations to targeted tissues, creating tiny gas-filled bubbles that destroy the tumour without thermal energy or high heat, principal investigator of the study Brian Goh told the media on June 11.

“It is the rapid expanding and collapsing of the micro-bubbles that mechanically break apart the tumour, turning it into a liquid state.

“The destruction happens only within what is known as ‘bubble cloud’, leaving the surrounding healthy tissues and organs alone,” said Goh, who heads the department of hepato-pancreato-biliary and transplant surgery at the Singapore General Hospital (SGH) and the National Cancer Centre Singapore (NCCS).

The destroyed tumour in a liquid state is drained from the body through its lymphatic drainage system.

In April 2025, the Li Ka Shing Foundation and Temasek Trust committed $12 million to bring histotripsy to Singapore and donated two histotripsy systems to NCCS and the National University Cancer Institute, Singapore, for trials here and in the region.

NCCS and SGH launched the trial – called Histotripsy for Ablation of Liver Tumours – in December that year with the first patient.

As at June 11, 2026, 10 patients with liver cancer, aged between 55 and 76, have undergone the procedure, including Mahamood.

“Mr Mahamood’s procedure went well. The tumour was in a good location, which is why he was offered the trial in the first place,” said Too Chow Wei, director of interventional oncology at NCCS.

“For him, the treatment was offered as bridging therapy, but for others, the intent is curative. For tumours that are under a certain size or of a certain type, the cure is reducing the bulk of the disease.”

The 10 patients in the trial will be monitored and assessed over the next two years.

Goh said histotripsy is highly effective in solid organs such as the liver, kidney and pancreas because they are dense, and the durable tissues can safely tolerate ultrasound targeting.

However, the procedure is currently approved by the US Food and Drug Administration only for the treatment of liver tumours.

Goh said the trial in Singapore is the only one in South-east Asia currently focused on Asians, while other trials were conducted in the West.

“In Asians, the liver is smaller, and sometimes people do not realise it sits right below the lung in Asians. This is different from Caucasians, and it can affect the ultrasound beams coming in,” he said.

“In the procedure, we sometimes need to collapse the lung a little bit to allow the sound waves to pass through.”

Goh noted that the main caveat is that the procedure is still on trial, with no certainty about the longer term.

“There is no good data, even internationally, on whether... the efficacy of histotripsy (after one year) is equivalent to what we have now, like in ablation or surgery,” he said.

“We know that it destroys the tumour in the short term. But what about in the longer term? No one knows.”

As for Mahamood, the hour-long procedure on March 19 has bought him waiting time for a donor liver.

He said: “My late parents and sister suffered from cancer. I witnessed their pain and now I have cancer. This trial has given me the hope they never had and I am thankful.”