A multi-institutional analysis of peritransplantation radiotherapy in patients with relapsed/refractory Hodgkin lymphoma undergoing autologous stem cell transplantation.

BACKGROUND: No consensus exists regarding the use of radiotherapy (RT) in conjunction with high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) for patients with relapsed/refractory classical Hodgkin lymphoma (HL). The objectives of the current study were to characterize practice patterns and assess the efficacy and toxicity of RT at 2 major transplantation centers.

METHODS: Eligible patients underwent HDC/ASCT from 2006 through 2015 using the combination of either carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM) or cyclophosphamide, BCNU, and etoposide (CBV).

RESULTS: For the cohort of 189 patients, the 4-year overall survival rate was 80%, the progression-free survival rate was 67%, and the local control (LC) rate was 68%. RT was used within 4 months of ASCT for 22 patients (12%) and was given more often for disease that was early stage, primary refractory, or [18 F]fluorodeoxyglucose (FDG)-avid at the time of HDC/ASCT. Disease recurrence occurring after HDC/ASCT was associated with primary refractory disease and FDG-avidity at the time of HDC/ASCT. RT was not found to be associated with LC, progression-free survival, or overall survival on univariate analysis. In a model incorporating primary refractory HL and FDG-avid disease at the time of HDC/ASCT, RT was found to be associated with a decreased risk of local disease recurrence (hazard ratio, 0.3; P = .02). In patients with primary refractory HL and/or FDG-avid disease at the time of HDC/ASCT, the 4-year LC rate was 81% with RT versus 49% without RT (P = .03). There was one case of Common Terminology Criteria for Adverse Events grade ≥ 3 RT-related toxicity (acute grade 3 pancytopenia).

CONCLUSIONS: In patients undergoing ASCT for relapsed/refractory HL, peritransplantation RT was used more often for disease that was early stage, primary refractory, or FDG-avid after salvage conventional-dose chemotherapy. RT was associated with improved LC of high-risk localized disease and was well tolerated with modern techniques. Cancer 2017;123:1363-1371. © 2016 American Cancer Society.