Poster Presentation 37th TROG Cancer Research Annual Scientific Meeting 2025

Advanced imaging to optimise stereotactic body radiation therapy for hepatocellular carcinoma: The PRISM clinical trial (#103)

Sirisha Tadimalla 1 , Tim Wang 2 , Fidel Navarro 1 , David Farlow 3 , Sheryl Foster 4 5 , Val Gebski 6 , Jonathan Sykes 2 , Jacob George 7 , Verity Ahern 2 , Steven Sourbron 8 , Annette Haworth 1 2
  1. Institute of Medical Physics, The University of Sydney, Camperdown, NSW, Australia
  2. Sydney West Radiation Oncology Network, Western Sydney Local Health District, Westmead, NSW, Australia
  3. Department of Nuclear Medicine, PET and Ultrasound, Westmead Hospital, Westmead, NSW, Australia
  4. Department of Radiology, Westmead Hospital, Westmead, NSW, Australia
  5. Sydney School of Health Sciences, Faculty of Medicine and Health, The University of Sydney , Camperdown, NSW, Australia
  6. NHMRC Clinical Trials Centre, The University of Sydney , Sydney, NSW, Australia
  7. Department of Gastroenterology and Hepatology, Westmead Hospital, Westmead, NSW, Australia
  8. Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK

Background: Stereotactic body radiation therapy (SBRT) is a treatment for hepatocellular carcinoma (HCC). However, patients with reduced liver function receive lower SBRT doses due to the risk of radiation-induced liver damage. Current SBRT planning does not account for spatial variations in liver function, which can be significant due to cirrhosis or prior liver-directed treatments. Retrospective studies indicate that using magnetic resonance imaging (MRI) could facilitate high-functioning liver sparing. However, reliable quantitative imaging measurements of liver function and the threshold dose for high-functioning liver are needed.

The Personalised liver SBRT using magnetic resonance imaging (PRISM) clinical trial is a prospective study investigating the feasibility of using MRI to optimise liver SBRT treatment to minimise dose to high-functioning regions of the liver, while sacrificing low-functioning liver to maximise dose to the tumour.

Aims: The PRISM trial will a) identify regions of high liver function using MRI and b) demonstrate optimised SBRT treatment planning guided by liver function maps.

Methods: Thirty participants undergoing liver SBRT will be recruited to undergo pre- and 3-month post-treatment MRI at 3T, and an optional mid-treatment scan for liver function mapping. Each time-point will include a 99mTc-Mebrofenin single-photon emission computed tomography (SPECT) scan for comparative liver function measurements. The dose-response relationship between radiation dose and liver function from MRI will be established to determine the threshold dose for high-functioning liver. A volunteer study is included to optimise MRI protocols and develop image processing pipelines.

Results: The study has received ethics approval (WSLHD-HREC: 2022/ETH00203). An MRI protocol has been optimised for quantitative measurement of liver fibrosis, perfusion and hepatocellular function. The study has received funding and has commenced participant recruitment.

Conclusions: The PRISM clinical trial will prospectively demonstrate optimisation of liver SBRT planning using MRI, enabling personalised treatment for patients with HCC.