ESTRO 37 Abstract book

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ESTRO 37

Analysis Research, Health Economics, Toronto, Canada 4 Cancer Care Ontario, Cancer Care Ontario, Toronto, Canada 5 Odette Cancer Centre, Radiation Oncology, Toronto, Canada 6 Odette Cancer Centre, Radiation Physics, Toronto, Canada 7 Aarhus University Hospital, Department of Oncology, Aarhus, Denmark 8 Canadian Centre for Applied Research in Cancer Control, Health Economics, Toronto, Canada Purpose or Objective Cervical cancer remains a significant problem worldwide. Patients with locally advanced cervical cancer traditionally received concurrent external beam radiation therapy and weekly cisplatin, followed by 2D brachytherapy (2DBT). 2DBT does not allow visualization of disease extent and organs at risk (OARs), and is associated with incomplete tumour coverage and/or excessive OAR doses in some patients. MR-guided 3D brachytherapy (MRgBT) overcomes these problems and is the gold standard for treatment planning. However, MR is not widely available in some regions and CT-guided 3D brachytherapy (CTgBT) is used instead despite suboptimal target visualization. This study evaluated the cost vs. utility of best-practice MRgBT compared to CTgBT in Ontario, Canada. Material and Methods A cost-utility analysis (CUA) was conducted from the perspective of the Ontario public healthcare payer using a four-state Markov cohort model and a five-year time horizon. Patients included in the model had locally advanced cervical cancer (FIGO IB-IV) requiring concurrent chemoradiation followed by brachytherapy. Parameters for the model were obtained from published literature and reviewed by an expert panel. The CUA evaluated treatment effectiveness, expressed as quality adjusted life years (QALYs), and costs, expressed in 2016 Canadian dollars, for MRgBT and CTgBT. Results were reported as incremental cost and effectiveness ratios comparing MRgBT to CTgBT for the entire patient cohort, and for low-risk (LR, FIGO IA-IIA) and high-risk (HR, FIGO IIB-IV) patients separately. The effect of parameter uncertainty on the results was explored using deterministic and probabilistic sensitivity analyses. Results MRgBT was both more effective and less costly compared to CTgBT for the full population and the high-risk subgroup. The incremental effectiveness ratios were 0.36 and 0.44 QALYs per patient for the full population and HR subgroup, respectively. The corresponding per patient incremental cost savings were $1,373 and $2,080, respectively. For the LR subgroup, MRgBT was more effective but also more costly than CTgBT, with an incremental effectiveness ratio of 276 QALYs per patient and an incremental cost of $1,324 per patient. MRgBT remained more effective in all deterministic and probabilistic sensitivity iterations and less costly in a substantial proportion of iterations when compared to CTgBT. Conclusion Overall, MRgBT is more effective and less costly than CTgBT from the perspective of the Ontario public healthcare payer. This provides evidence to build provincial and national capacity for MRgBT, and guidance for policy-makers about future infrastructure and human resource investments to assure the availability of this treatment for all women with locally advanced cervical cancer.

Conclusion This study showed promising results concerning the use of per-BT MRI textural features for predicting relapse in LACC. A methodology was proposed and a powerful signature of recurrence was established on routine acquisitions. This method has to be validated in an external cohort before considering a clinical use for treatment personalization. OC-0076 MR-guided vs CT-guided brachytherapy more effective and less costly in locally advanced cervical cancer J. Skliarenko 1 , D. D'Souza 2 , J. Perdrizet 3 , M. Ang 4 , L. Barbera 5 , E. Gutierrez 4 , A. Ravi 6 , K. Tanderup 7 , P. Warde 4 , K. Chan 4 , W. Isaranuwatchai 8 , M. Milosevic 1 1 Princess Margaret Cancer Centre, Radiation Medicine Program, Toronto, Canada 2 London Health Sciences Centre, Radiation Oncology, London, Canada 3 St. Michael’s Hospital Centre for Excellence in Economic