Quality control of involved-field radiotherapy for patients with early stage Hodgkin's lymphoma based on a central prospective review. Comparison of the results between two study generations of the German Hodgkin Study Group

Abstract

Purpose: Based on experience in trials HD10 and HD11 (1998-2003), the radiotherapy reference center of the German Hodgkin Study Group (GHSG) continued their central prospective radiation oncological review in trials HD13 and HD14. The purpose of this analysis was to identify the impact of this procedure on radiotherapeutic management and to compare findings with former trials.

Methods: Between 2003 and 2009, 1,710 patients were enrolled in the HD13 trial (early favorable stages) and 2,039 patients in the HD14 trial (early unfavorable stages). All patients received a total of 30 Gy involved-field (IF) radiotherapy within a combined modality approach.

Results: For patients in HD13, there was a correction of disease involvement in 847/1,518 patients (56%), and for patients in HD14 in 1,370/1,905 patients (72%). Most discrepancies were observed in the lower mediastinum (19.2%), infraclavicular (31.7%), upper cervical (12.7%), and supraclavicular (10.8%) lymph nodes. This resulted in a change of disease stage in 241 (7%) patients and a shift into another study protocol in 66 (2%) patients. Due to the incorrect lymph node documentation of the participating study centers, the IF radiotherapy volume had to be enlarged in 1,063/3,423 patients (31%) and reduced in 244/3,423 patients (7.1%). These findings are comparable to the results of the quality control in the trials HD10 and HD11 (2,611 patients reviewed).

Conclusion: Central review of the diagnostic imaging and clinical findings of Hodgkin's lymphoma patients shows a considerable number of discrepancies compared with the local evaluation. Thus, meticulous evaluation of all imaging information in close collaboration between the radiation oncologist and diagnostic radiologist is mandatory.