S1401
Interdisciplinary - Health economics & health services research
ESTRO 2026
The optimal radiotherapy utilisation in colorectal cancer was estimated to be 16% (range 14.6% - 18.1%) with an estimated optimal number of fractions per patient of 3.8 (range 1.0-4.7), based on the updated evidence-based guidelines (Figures 1 and 2). Radiotherapy is recommended in 60.1% of rectal cancer and less than 1% of colon cancer patients. The estimated optimal number of fractions per patient was 14.7 and 0.03 for rectal and colon cancer, respectively.
Digital Poster 2415 estimating the optimal use of radiotherapy in colorectal cancer: updated model of utilisation and number of fractions in contemporary practice Anzela Anzela 1,2 , Karen Wong 1,2 , Mei Ling Yap 1,2 , Vikneswary Batumalai 2,3 , Geoff Delaney 1,2 1 Liverpool and Macarthur Cancer Therapy Centre, South Western Local Health District, Liverpool, NSW, Australia. 2 Collaboration for Cancer Outcomes, Research and Evaluation (CCORE), Ingham Institute, Liverpool, NSW, Australia. 3 The George Institute for Global Health, UNSW Sydney, Randwick, NSW, Australia Purpose/Objective: Colorectal cancer is the second leading cause of cancer mortality in Australia. Radiotherapy is an essential part of management, particularly in locally advanced rectal cancer. Emerging evidence in total neoadjuvant therapy, organ-preservation strategies, advances in personalised therapy and the use of stereotactic radiotherapy in oligometastatic disease have influenced both systemic and local management approaches. Modelling of optimal, evidence-based radiotherapy is important for resource planning and benchmarking [1-3]. Previous modelling estimated the optimal radiotherapy utilisation rate of 4% for colon cancer and 60% for rectal cancer, with an average of 0.1 and 14.4 fractions per patient, respectively [4, 5]. This study aims to update the Australian model of optimal radiotherapy utilisation (RTU) and number of fractions (RTF) for the first course of radiotherapy in colorectal cancer to incorporate contemporary staging, molecular classification, and evidence-based guideline recommendations. Material/Methods: This study utilised the Collaboration for Cancer Outcomes Research and Evaluation (CCORE) model of optimal radiotherapy utilisation and number of fractions initially developed in 2003 and updated in 2012 and 2015 [4-6]. An optimal radiotherapy decision tree for colorectal cancer was constructed based on national and international guidelines published between 2020 and 2025. The proportion of patients with an indication for radiotherapy were derived primarily from Australian population-based data. Guideline-recommended fractionation schedules were assigned to each indication. The optimal radiotherapy utilisation rate was determined by calculating the proportion of patients for whom radiotherapy is indicated. The overall optimal number of fractions was determined by weighting each fractionation schedules according to the frequency of specific clinical scenarios. Sensitivity analyses were performed to assess impact of uncertainties on model estimates. Results:
Conclusion: The estimated optimal radiotherapy utilisation and number of fractions per patient are unchanged in rectal cancer and lower in colon cancer when compared to the previous modelling. This study provides an updated benchmark for the optimal use of radiotherapy in colorectal cancer. The model can be adapted to different populations to evaluate access, efficiency, and cost-effectiveness, supporting equitable and evidence-based radiation oncology care. References: 1.Barton MB, F.M., Olver I, Cox X, et al, A cancer services framework for Victoria and future directions for the Peter MacCallum Cancer Institute. A report from a consortium led by the Collaboration for Cancer Outcomes Research and Evaluation (CCORE).2.Bentzen, S.M., et al. Radiother Oncol, 2005.
Made with FlippingBook - Share PDF online