The search textbox has an autosuggest feature. When you enter three or more characters, a list of up to 10 suggestions will popup under the textbox. Use the arrow keys to move through the suggestions. To select a suggestion, hit the enter key. Using the escape key closes the listbox and puts you back at the textbox. The radio buttons allow you to toggle between having all search items start with or contain the text you entered in the search box.
A chemotherapy regimen consisting of vincristine, doxorubicin hydrochloride (Adriamycin), methotrexate and prednisone used in combination with radiation therapy for the treatment of low-risk childhood Hodgkin lymphoma. (NCI Thesaurus)