[1] Norwegian Univ Sci & Technol, Fac Med & Hlth Sci, European Palliat Care Res Ctr PRC, Dept Clin & Mol Med,NTNU, N-7491 Trondheim, Norway
[2] Trondheim Reg & Univ Hosp, St Olavs Hosp, Canc Clin, Trondheim, Norway
[3] Norwegian Univ Sci & Technol, Dept Neuromed & Movement Sci, Trondheim, Norway
[4] Trondheim Reg & Univ Hosp, St Olavs Hosp, Dept Neurol & Clin Neurophysiol, Trondheim, Norway
[5] Univ Aberdeen, Div Appl Hlth Sci, Aberdeen, Scotland
[6] Univ Oslo, Oslo Univ Hosp, European Palliat Care Res Ctr PRC, Dept Oncol,Inst Clin Med, Oslo, Norway
[7] Oslo Univ Hosp, Dept Oncol, Oslo, Norway
[8] Univ Oslo, Oslo, Norway
[9] Kliniken Essen Mitte, Dept Palliat Med Inst Palliat Care, Essen, Germany
[10] Univ Hosp Carl Gustav Carus, Comprehens Pain Ctr, Dresden, Germany
[11] Trondheim Reg & Univ Hosp, St Olavs Hosp, Dept Anaesthesiol & Intens Care Med, Trondheim, Norway
[12] Norwegian Univ Sci & Technol, Fac Med & Hlth Sci, Dept Circulat & Med Imaging, NTNU, Trondheim, Norway