Observer Variation in Interpreting F-18-FDG PET/CT Findings for Lymphoma Staging

TY - JOUR

T1 - Observer Variation in Interpreting F-18-FDG PET/CT Findings for Lymphoma Staging

AU - Hofman, Michael S.

AU - Smeeton, Nigel C.

AU - Rankin, Sheila C.

AU - Nunan, Tom

AU - O'Doherty, Michael J.

PY - 2009/10/1

Y1 - 2009/10/1

N2 - Many studies demonstrate a high accuracy for PET in staging lymphoma, but few assess observer variation. This study quantified agreement for staging lymphoma with PET/CT. Methods: The PET/CT images of 100 patients with lymphoma who had been referred for staging were reviewed by 3 experienced observers, with 2 observers reviewing each series a second time. Ann Arbor stage and individual nodal and extranodal regions were assessed. Weighted kappa (kappa(w)) and intraclass correlation coefficient were used to compare ratings. Results: Intra- and interobserver agreement was high for Ann Arbor stage (kappa(w) - 0.79-0.91), number of nodal regions involved (intraclass correlation coefficient, 0.83-0.93), and presence of extranodal disease (kappa = 0.74-0.86). High agreement was also observed for all nodal regions (kappa(w) > 0.60) except hilar (kappa(w) = 0.56-0.82) and infraclavicular (kappa(w) = 0.14-0.55). Lower agreement was observed for bowel involvement (kappa(w) = 0.37-0.71). Conclusion: Experienced observers had a high level of agreement using PET/CT for lymphoma staging, supporting its use as a robust noninvasive staging tool. Further research is needed to evaluate observer variability for restaging during and after chemotherapy.

AB - Many studies demonstrate a high accuracy for PET in staging lymphoma, but few assess observer variation. This study quantified agreement for staging lymphoma with PET/CT. Methods: The PET/CT images of 100 patients with lymphoma who had been referred for staging were reviewed by 3 experienced observers, with 2 observers reviewing each series a second time. Ann Arbor stage and individual nodal and extranodal regions were assessed. Weighted kappa (kappa(w)) and intraclass correlation coefficient were used to compare ratings. Results: Intra- and interobserver agreement was high for Ann Arbor stage (kappa(w) - 0.79-0.91), number of nodal regions involved (intraclass correlation coefficient, 0.83-0.93), and presence of extranodal disease (kappa = 0.74-0.86). High agreement was also observed for all nodal regions (kappa(w) > 0.60) except hilar (kappa(w) = 0.56-0.82) and infraclavicular (kappa(w) = 0.14-0.55). Lower agreement was observed for bowel involvement (kappa(w) = 0.37-0.71). Conclusion: Experienced observers had a high level of agreement using PET/CT for lymphoma staging, supporting its use as a robust noninvasive staging tool. Further research is needed to evaluate observer variability for restaging during and after chemotherapy.

U2 - 10.2967/jnumed.109.064121

DO - 10.2967/jnumed.109.064121

M3 - Article

VL - 50

SP - 1594

EP - 1597

JO - Journal of Nuclear Medicine

JF - Journal of Nuclear Medicine

IS - 10

ER -