[1] Eberhard Karls Univ Tubingen, Univ Hosp, Dept Radiat Oncol, Tubingen, Germany
[2] Eberhard Karls Univ Tubingen, Med Fac, Tubingen, Germany
[3] Royal Marsden NHS Fdn Trust, Dept Radiotherapy, Sutton, Surrey, England
[4] Inst Canc Res, Sutton, Surrey, England
[5] Antoni Van Leeuwenhoek Hosp, Netherlands Canc Inst, Dept Radiotherapy, Amsterdam, Netherlands
[6] Univ Texas MD Anderson Canc Ctr, Dept Radiat Oncol, Houston, TX USA
[7] Med Coll Wisconsin, Dept Radiat Oncol, Milwaukee, WI USA
[8] Sunnybrook Hlth Sci Ctr, Odette Canc Ctr, Dept Radiat Oncol, Toronto, ON, Canada
[9] Princess Margaret Canc Ctr, Dept Radiat Oncol, Toronto, ON, Canada
[10] Christie NHS Fdn Trust, Dept Clin Oncol, Manchester, England
[11] Odense Univ Hosp, Dept Oncol, Odense, Denmark
[12] Amsterdam UMC, Dept Radiat Oncol, Amsterdam, Netherlands
[13] Univ Med Ctr Utrecht, Dept Radiat Oncol, Utrecht, Netherlands
[14] Eberhard Karls Univ Tubingen, Univ Hosp, Sect Biomed Phys, Dept Radiat Oncol, Tubingen, Germany
[15] German Canc Consortium DKTK, Partner Site Tubingen, Tubingen, Germany
[16] German Canc Res Ctr, Heidelberg, Germany