In response to "Histopathologic validation of 3′-deoxy-3′-18F-fluorothymidine PET for detecting tumour repopulation during fractionated radiotherapy in human FaDu squamous cell carcinoma in nude mice". Issue 3 (March 2015) - Troost, Esther G.C.; Hoeben, Bianca A.W.; Laverman, Peter; Bussink, Jan; Oyen, Wim J.G.