ESTRO 2024 - Abstract Book

S2262

Clinical - Upper GI

ESTRO 2024

Douglas H Brand 1,2 , Alya Al-Siyabi 1 , Katie Ball 3,4 , Stuart Brown 4 , Roopinder Gillmore 4 , Daniel Krell 4 , Aileen Marshall 5,6 , Douglas MacDonald 5 , Sophie Brown 5 , Donna O'Sullivan 5 , Maria Ciaponi 5 , Thomas Richards 2 , Glen Blackman 2 , Tim Meyer 4,7 , Maria Hawkins 1,2 1 University College London, Dept of Medical Physics and Bioengineering, London, United Kingdom. 2 University College London Hospitals, Oncology Division, London, United Kingdom. 3 Cambridge University NHS Foundation Trust, Oncology Department, Cambridge, United Kingdom. 4 Royal Free Hospital, Oncology Department, London, United Kingdom. 5 Royal Free Hospital, Hepatology Department, London, United Kingdom. 6 University College London, Institute of Liver and Digestive Health, London, United Kingdom. 7 University College London, Institute of Immunity and Transplantation, London, United Kingdom Hepatocellular carcinoma (HCC) typically arises from chronic liver disease (CLD), commonly caused by alcohol, hepatitis viridae and non-alcoholic fatty liver disease (NAFLD). Stereotactic body radiotherapy (SBRT) is an emerging treatment modality for HCC, involving highly conformal, precisely targeted radiotherapy, given over five or fewer fractions. Substantial non-randomised data has accrued to support its usage in HCC (1). Within the UK, national commissioning of SBRT for HCC was started in April 2020 (2). This was based upon the contemporaneous non-randomised literature, plus data on 91 patients recruited to the National Health Service (NHS) Commissioning Through Evaluation (CtE) programme that ran between 2015 – 2018 (3). In the CtE programme HCC patients had to be unsuitable for resection, transplant or RFA and unsuitable/refractory to TAE, with maximum Child-Pugh A and 50mm tumour. Here we examine SBRT treatment outcomes for HCC patients treated since the introduction of this treatment to the UK. Single centre study, with institutional approval, examining HCC patients treated with SBRT between May 2020-May 2023. Eligible patients for this study had a primary diagnosis of HCC (either pathological or radiological), were treated with SBRT (five or fewer fractions) to their liver and had minimum 6 months follow-up. SBRT to HCC oligometastases were excluded, along with non-stereotactic palliative treatments. Patient set-up is supine, scanned with IV and oral contrast in external breath hold with abdominal compression. Gross tumour volume (GTV) delineation is aided by fused diagnostic MRI liver (or triple phase CT). Internal motion is accounted for by an iGTV generated from 4DCT. iGTV + 5mm isotropic margin = planning target volume (PTV). Treatment is delivered as volumetric modulated arc therapy (VMAT) on C-arm LINAC, with daily online cone-beam CT, without fiducials. Purpose/Objective: Material/Methods:

Data were collected using the electronic health record. Analysis was performed in Stata version 17. Model for End Stage Liver Disease (MELD) version 3 was calculated (4).

Results:

63 patients met the inclusion criteria, with median follow-up 23 months, (range 6 – 40 months). Table 1 summarises categorical information. Median age was 71 years (Interquartile Range (IQR) 65 – 74 years), with most having known