Question: How is the clinical text structuring task defined?
Answer: Clinical text structuring (CTS) is a critical task for fetching medical research data from electronic health records (EHRs), where structural patient medical data, such as whether the patient has specific symptoms, diseases, or what the tumor size is, how far from the tumor is cut at during the surgery, or what the specific laboratory test result is, are obtained., Unlike the traditional CTS task, our QA-CTS task aims to discover the most related text from original paragraph text. 
Alternative answer: CTS is extracting structural data from medical research data (unstructured). Authors define QA-CTS task that aims to discover most related text from original text.