[1] Royal Coll Radiologists, 63 Lincolns Inn Fields, London WC2A 3JW, England
[2] St James Univ Hosp, Leeds Canc Ctr, Beckett St, Leeds, England
[3] Norfolk & Norwich Univ Hosp Fdn Trust, Norwich, England
[4] Univ Leeds, Leeds Inst Hlth Sci, Leeds, England
[5] Weston Pk Hosp, Whitham Rd, Sheffield, England
[6] Christie NHS Fdn Trust, Wilmslow Rd, Manchester, England