Interobserver Variability in the Detection of Cervical-Thoracic Hodgkin's Disease by Computed Tomography

Computed tomography (CT) scans of the neck and chest are obtained at diagnosis of Hodgkin's disease to establish disease extent, plan radiotherapy, and serve as baseline studies for subsequent evaluation of response to therapy. However, differences in interpretation may occur even among experienced radiologists. This study was designed to test the extent of variation among expert radiologists' interpretations and to assess how their interpretations differed from that of the primary (institutional) radiologists. Five radiologists independently reviewed randomly selected CT scans of 59 patients enrolled onto two Pediatric Oncology Group Hodgkin's disease treatment protocols. For each patient, 31 potential disease sites were scored as positive, negative, uncertain, or unassessable. Agreement among the reviewers and between the reviewers and the primary readers was analyzed. For 58% of the sites, at least four of the five reviewers agreed in >/= 80% of the cases. Kappa analysis showed moderate agreement in approximately two thirds of the sites and poor agreement in the remainder. There was moderate agreement between a majority of the expert readers and the primary radiologist reports for approximately one third of the sites, and agreement was poor in two thirds. There are disparities among radiologists' interpretations of cervical-thoracic CT imaging of patients with Hodgkin's disease. This variability may affect patient care and the performance and results of multi-institutional clinical trials. We propose that a standardized method of reporting might improve the consistency of interpretation of CT scans in these patients.