[1] Univ Zurich Hosp, Dept Oncol, CH-8091 Zurich, Switzerland
[2] Univ Zurich, Inst Social & Prevent Med, Biostat Unit, CH-8006 Zurich, Switzerland
[3] Triemli City Hosp, Zurich, Switzerland
[4] Univ Zurich Hosp, Div Nucl Med, Dept Med Radiol, CH-8091 Zurich, Switzerland