PET-CT for staging & early response: results from 'Response Adapted Therapy in Advanced Hodgkin Lymphoma' (RATHL) (CRUK/07/033).

Research output: Contribution to journalArticle


International guidelines recommend PET-CT should replace CT in Hodgkin Lymphoma (HL). The aims of this study were to i) compare PET-CT with CT for staging and ii) measure agreement between expert and local readers, using a five-point scale (Deauville criteria), to adapt treatment in a clinical trial 'Response Adapted Therapy in Advanced Hodgkin Lymphoma' (RATHL), reference NCT00678327. Patients were staged for the trial using clinical assessment, CT and bone marrow biopsy (RATHL stage). PET-CT was performed at baseline (PET0) and after 2 chemotherapy cycles (PET2) in a response-adapted design. PET-CT was reported centrally by experts at 5 national core labs. Local readers optionally scored PET2 scans. The RATHL and PET-CT stages were compared. Agreement amongst experts and between expert and local readers was measured. RATHL and PET0 stage were concordant in 938 (80%) patients. PET-CT upstaged 159 (14%) and downstaged 74 (6%) patients. Upstaging by extranodal disease in bone marrow (92), lung (11) or multiple sites (12) on PET-CT accounted for most discrepancies. Follow-up of discrepant findings confirmed the PET characterisation of lesions in the vast majority. Five patients were upstaged by marrow biopsy; 7 by contrast-enhanced CT in bowel and/or liver or spleen. PET2 agreement amongst experts (140 scans) with kappa (95% CI) of 0.84 (0.76 - 0.91) was very good and between experts and local readers (300 scans) at 0.77 (0.68-0.86) was good. These results confirm PET-CT as the modern standard for staging HL and that response assessment using Deauville criteria is robust enabling translation of RATHL results into clinical practice.


  • Sally F Barrington
  • Amy A Kirkwood
  • Antonella Franceschetto
  • Michael J Fulham
  • Thomas H Roberts
  • Helén Almquist
  • Karin Hjorthaug
  • Zaid N Viney
  • Lucy C Pike
  • Massimo Federico
  • Stefano Luminari
  • John Radford
  • Judith Trotman
  • Alexander Fosså
  • Leanne Berkahn
  • Daniel Molin
  • Francesco D'Amore
  • Donald A Sinclair
  • Paul Smith
  • Michael J O'Doherty
  • Lindsey Stevens
  • Peter W Johnson
External organisations
  • King's College London
  • University College London
  • University of Modena
  • Royal Prince Alfred Hospital
  • Aarhus University Hospital
  • Guy's and St Thomas' NHS Foundation Trust
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Radiology, Nuclear Medicine and Medical Imaging
Original languageEnglish
Pages (from-to)1531 - 1538
Issue number12
Early online date2016 Jan 8
Publication statusPublished - 2016 Mar
Publication categoryResearch