Centralized radiation oncologic review of cross-sectional imaging of Hodgkin's disease leads to significant changes in required involved field—results of a quality assurance program of the German Hodgkin Study Group

Abstract Purpose To guarantee the treatment quality of involved-field radiotherapy (IF-RT) of patients in the Hodgkin's disease (HD)10 and HD11 trials of the German Hodgkin Study Group, with 460 participating study centers, a quality assurance program was conducted. It was based on a central prospective radiation oncologic review of all patients' entire diagnostic imaging and clinical findings. An individual RT prescription was provided for every study patient. The purpose of the present investigation was to assess the feasibility of such a procedure and its impact on the final definition of disease extension and patient treatment. Methods and materials Between 1998 and 2002, 1371 patients were enrolled into the HD10 trial (early-stage disease) and 1570 patients into the HD11 trial (intermediate-stage disease). The HD10 trial tested four cycles of Adriamycin (doxorubicin), bleomycin, vinblastine, and dacarbazine (ABVD) against two cycles of ABVD followed by 20 Gy of IF-RT vs. 30 Gy of IF-RT (four study arms). The HD11 trial compared four cycles of ABVD with four cycles of BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) baseline followed by 20 Gy IF-RT vs. 30 Gy IF-RT in a four-arm design. All study centers were required to score disease involvement at a total of 34 possible anatomic sites on case report forms and send them, together with all diagnostic imaging, to the RT reference center in Cologne, Germany. Images were reviewed there by a panel of expert radiation oncologists and radiologists and compared with the case report form. Differences between the disease involvement documented by the participating center and the reference center were recorded. Subsequently, an individualized treatment proposal was compiled. Complete sets of documentation were submitted to the reference center for 89% of the patients in both HD10 and HD11. Results A considerable proportion of involved sites were incorrectly recorded on the corresponding case report form by the participating center. For patients with early-stage HD (HD10), there was a correction of disease involvement in 49% (593 of 1214 patients) and for patients with intermediate-stage HD (HD11) in 67% (936 of 1397 patients). Most discrepancies were seen in the lower mediastinum (23%), infraclavicular (17%), upper cervical (16%), supraclavicular (13%), and pulmonary hilar region (13%). This resulted in a change of disease stage in 41 of those 1,529 patients whose documented disease involvement had to be corrected (2.7%). Ninety-three patients had to be treated in a different protocol, because of changes in stage and risk factors. Owing to incorrect lymph node documentation of the participating centers, the RT treatment volume had to be enlarged in 891 (34%) and reduced in 82 (3%) of 2,611 patients. Conclusion A central prospective review of patient data and consecutive prescription of individual RT treatment volume is feasible within large multicenter trials for HD. Such a procedure has a significant impact on the correctness of stage definition, allocation to treatment groups, and extent of the IF treatment volume.