<qa>  What is the only way to continue treatment with vandetanib?Patients receive docetaxel IV over 1 hour on day 1 and oral vandetanib once daily on days 1-21. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. After 6 weeks of treatment, patients who experience clinical benefit but poor tolerance to docetaxel may continue treatment with vandetanib alone. 