[1] Med Univ Vienna, Comprehens Canc Ctr, Dept Radiat Oncol, Gen Hosp Vienna, Spitalgasse 23, A-1090 Vienna, Austria
[2] Univ Med Ctr, Utrecht, Netherlands
[3] Gustave Roussy, Dept Radiotherapy, Villejuif, France
[4] Aarhus Univ Hosp, Dept Oncol, Aarhus, Denmark
[5] Mt Vernon Canc Ctr, Northwood, Middx, England
[6] Tata Mem Hosp, Dept Radiat Oncol, Mumbai, Maharashtra, India
[7] Inst Oncol Ljubljana, Dept Oncol, Ljubljana, Slovenia
[8] Oslo Univ Hosp, Dept Oncol, Norwegian Radium Hosp, Oslo, Norway
[9] Cross Canc Inst, Dept Oncol, Edmonton, AB, Canada
[10] Univ Alberta, Edmonton, AB, Canada
[11] Postgrad Inst Med Educ & Res, Dept Radiotherapy & Oncol, Chandigarh, India
[12] St James Univ Hosp, Leeds Canc Ctr, Leeds, W Yorkshire, England
[13] Radiat Oncol Dept, Radiotherapy Grp, Arnhem, Netherlands
[14] Univ Hosp Leuven, Dept Radiat Oncol, Leuven, Belgium
[15] Univ Amsterdam, Amsterdam Univ Med Ctr, Dept Radiat Oncol, Amsterdam, Netherlands
[16] St Olavs Hosp, Clin Oncol & Womens Clin, Trondheim, Norway
[17] Cambridge Univ Hosp NHS Fdn Trust, Oncol Ctr, Addenbrookes Hosp, Cambridge, England
[18] Erasmus Univ, Dept Radiat Oncol, Erasmus MC, Rotterdam, Netherlands