Benefit of radiation therapy in stage III-IV Hodgkin lymphoma after chemotherapy

Abstract

Background: The benefit of radiation therapy as a consolidation therapy after chemotherapy in advanced-stage Hodgkin lymphoma remains controversial, especially after the widespread use of positron emission tomography (PET)/computed tomography (CT) or Ga-67 scintigraphy.

Objective: We conducted a retrospective review in our institute to evaluate the benefit of consolidative radiotherapy in patients who received a modern chemotherapy regimen.

Materials and methods: Between January 2010 and December 2019, 33 patients with newly diagnosed stage III or IV Hodgkin lymphoma were identified from the Chulabhorn Hospital database. After excluding 15 patients who did not meet our inclusion criteria (1 HIV infection, 5 early-stage after reviewed, 5 did not used PET-CT or Ga-67 scintigraphy and 4 with incomplete medical history), the remaining 18 patients were enrolled.

Results: After a median follow-up of 48 months, the 3-year disease-free survival rate was 66.7% in patients who received radiation therapy, versus 55.6% in patients who did not receive radiation therapy (p = 0.391). The 3-year overall survival rate was 100% in both groups. In total, 11 patients (61%) had complete metabolic response (CMR) after first-line chemotherapy, whereas three (16.7%), one (5.6%), and three (16.7%) had a partial response, stable disease, and disease progression, respectively. Seven patients (38.9%) experienced relapse after treatment, and 71.4% of relapses occurred at the original disease site. Of 7 patients who had residual after first-line chemotherapy, three received further radiotherapy whereas four did not. Relapse occurred in all four patients who did not received radiotherapy after residual disease. No patients who achieved CMR in both the interim and post-treatment evaluations experienced relapse. Four of nine patients with bulky masses more than 7 cm in size had CMR after first-line chemotherapy. Interestingly, in this group, no relapse occurred in patients who did not receive radiation therapy, whereas one of three patients (33.3%) who received radiation therapy exhibited relapse. No grade 3–4 acute radiation toxicities occurred in this study, but two of nine patients (22.2%) had grade 3 late pneumonitis that required hospitalization. No secondary malignancy was observed.

Conclusion: Using functional imaging as an evaluation method, consolidation radiation therapy may not be necessary in advanced Hodgkin lymphoma.