[1] Univ Hosp Gasthuisberg, Dept Radiotherapy, B-3000 Louvain, Belgium
[2] Med Univ Vienna, Dept Radiotherapy & Radiobiol, Vienna, Austria
[3] Inst Gustave Roussy, Dept Radiotherapy, Brachytherapy Unit, Villejuif, France
[4] Hop Cantonal Univ Geneva, Geneva, Switzerland