Reply to Filippo Alongi, Rosario Mazzola, Dario Aiello and Matteo Salgarello's Letter to the Editor re: Re: Daniel E. Spratt, Hebert A. Vargas, Zachary S. Zumsteg, et al. Patterns of Lymph Node Failure after Dose-escalated Radiotherapy: Implications for Extended Pelvic Lymph Node Coverage. Eur Urol 2017;71:37-43. A Step Forward in the Era of Functional Imaging?: Functional Imaging and Micrometastatic Disease: Implications for Radiotherapy Field Design.