[1] Leiden Univ, Med Ctr, Dept Radiat Oncol, NL-2300 RC Leiden, Netherlands
[2] Univ Med Ctr Utrecht, Dept Radiat Oncol, Utrecht, Netherlands
[3] Medisch Spectrum Twente, Dept Radiotherapy, Enschede, Netherlands
[4] Univ Med Ctr Maastricht, Dept Radiat Oncol MAASTRO, Maastricht, Netherlands
[5] Arnhem Radiotherapy Inst ARTI, Arnhem, Netherlands
[6] Erasmus MC Daniel Hoed Canc Ctr, Dept Radiat Oncol, Rotterdam, Netherlands
[7] Radiotherapy Inst Friesland, Leeuwarden, Netherlands
[8] Radiotherapy Grp Deventer, Dept Radiat Oncol, Deventer, Netherlands
[9] Netherlands Comprehens Canc Org, Res Dept, Eindhoven, Netherlands
[10] Tilburg Univ, Ctr Res Psychol Somat Dis, NL-5000 LE Tilburg, Netherlands
[11] Leiden Univ, Med Ctr, Dept Med Stat, Leiden, Netherlands
[12] Netherlands West Leiden, Ctr Comprehens Canc, Leiden, Netherlands
[13] Univ Groningen, Univ Med Ctr Groningen, Dept Gynecol Oncol, NL-9713 AV Groningen, Netherlands