Comparison of Gradient-Based Edge Detectors Applied on Mammograms

Breast cancer is one of the most common types of cancer amongst women, but it is also one of the most frequently cured cancers. Because of this, early detection is crucial, and this can be done through mammography screening. With the increasing need of an automated interpretation system, a lot of methods have been proposed so far and, regardless of the algorithms, they all share a step: pre-processing. That is, identifying the image orientation, detecting the breast and eliminating irrelevant parts. This paper aims to describe, analyze, compare and evaluate six of the most commonly used edge detection operators: Sobel, Roberts Cross, Prewitt, Farid and Simoncelli, Scharr and Canny. We detail the algorithms, their implementations and the metrics used for evaluation and continue by comparing the operators both visually and numerically, finally concluding that Canny best suit our needs.

OP181 Adapting Evidence To Produce A Health Technology Assessment Of Mammography Screening: An Example From The West Bank

IntroductionHealth technology assessment (HTA) can play a key role in evidence-based decision-making. However, HTA requires resources that might be lacking in low-income settings. To test the feasibility of adapting existing evidence as part of the HTA process, this project evaluated the effectiveness and economic impact of breast cancer screening programs for women over 40 years in the West Bank, where mammography screening is provided for free in governmental clinics.MethodsWe conducted a search for systematic reviews, HTAs and guidelines in electronic databases. We included the most recent global systematic review and meta-analysis that fulfilled our inclusion criteria. The European Network for Health Technology Assessment (EUnetHTA) adaptation toolkit was used to guide adaptation and undertake a budget impact analysis of the economic impact of mammography screening. We build capacity by working as a team of HTA experts and first-time HTA researchers. The results were disseminated to raise awareness for HTA.ResultsThe European Commission Guidelines on Breast Cancer Screening were identified as most recent global systematic review with meta-analyses, out of 2,365 references. The adapted evidence may inform policies on screening in the West Bank. Our experience is that adaption requires extensive skills and resources, including finding, assessing, and adapting relevant evidence. The EUnetHTA toolkit is useful, but also adds to the workload. Furthermore, local stakeholder engagement is important in topic selection, to access information, and to contextualize global evidence to the local setting.ConclusionsThis study is currently ongoing, but preliminary findings show that producing an HTA by adapting existing evidence in resource-limited settings is feasible. There is a need for nuanced guidance on transferability of evidence from other settings. Future studies should investigate innovative methods to optimize the adaption process. Capacity building in adaptation is important to ensure the production of quality HTA products. Inclusion of local team members and stakeholders is important for future development of HTA in the region.