Role of Consolidative Radiation Therapy After Autologous Hematopoietic Cell Transplantation for the Treatment of Relapsed or Refractory Hodgkin Lymphoma

Purpose To evaluate the role of the addition of consolidative radiation therapy after high-dose chemotherapy and autologous hematopoietic cell transplantation (AHCT) for relapsed or refractory Hodgkin lymphoma (HL). Methods and Materials Medical records were reviewed from a total of 80 consecutive patients who underwent high-dose chemotherapy with AHCT treated under a single protocol at University of Minnesota between November 2005 and January 2014. Of these, 32 patients received radiation therapy after AHCT as planned consolidation. Results At a median follow-up of 25 months, the 2-year overall survival (OS) and progression-free survival (PFS) for the entire cohort was 96% and 52%, respectively. Consolidative radiation therapy was found to significantly improve the 2-year PFS (67% vs 42%, P<.01) without a significant change in OS (100% vs 93%, P=.15). On subgroup analysis, consolidative radiation therapy was shown to improve PFS in patients with bulky disease (62% vs 39%, P=.02), B-symptoms (48% vs 28%, P=.05), primary refractory disease (47% vs 32%, P=.02), and those with a partial response on pretransplant imaging (47% vs 32%, P=.02). The improvement seen on 2-year PFS with consolidative radiation therapy remained significant on multivariate analysis (hazard ratio 4.64, 95% confidence interval 1.98-10.88). Minimal toxicity was observed among the patients receiving radiation therapy. Conclusions The addition of consolidative radiation therapy after high-dose chemotherapy and AHCT demonstrated a significant improvement in 2-year PFS and no impact on OS. Radiation therapy was well tolerated, with minimal toxicity. Our study supports a role of consolidative radiation therapy in patients with HL treated with AHCT.