**5.4 Theranostics: Zevalin therapy**

Zevalin therapy is used for determining the indications for relapsed or refractory, low-grade or follicular, B-cell non-Hodgkin's lymphoma. Zevalin is FDA approved for the treatment of relapsed or refractory low-grade follicular. In the year 2008 Zevalin was approved as the first-line drug for follicular lymphoma in the European Union.
