Evaluating the long-term outcomes of low-dose radiation therapy for early-stage nodular lymphocyte-predominant Hodgkin lymphoma

This study evaluated the effectiveness of radiation, chemotherapy, or both for the treatment of early-stage nodular lymphocyte-predominant Hodgkin’s lymphoma (NLPHL). This study concluded that long-term outcomes were favorable across all treatment approaches.

NLPHL is a rare subtype of non-Hodgkin's lymphoma. Most patients with NLPHL have early-stage (stage 1 or 2) disease. A variety of therapy approaches are used to treat these patients. Surgery, radiation, and rituximab (Rituxan) with or without chemotherapy are commonly used. Radiation therapy can also be combined with chemotherapy. This type of treatment is called combined modality therapy (CMT).

Previous studies have shown that radiation therapy alone can be highly effective for patients with NLPHL. However, using high doses of radiation over large areas of the body (extended-field radiation therapy; EFRT) can lead to long-term side effects. Using smaller doses of radiation that are targeted at smaller areas of tissue may help reduce side effects. This is called involved-side radiation therapy (ISRT). Whether this approach is more effective than CMT for the treatment of early-stage NLPHL is unclear.

This study had 71 patients with early-stage NLPHL. 51% of the patients received radiation therapy only. 8% of patients received systemic chemotherapy only. 41% of patients received both types of therapy (combined therapy). Patients were followed-up for an average of 6.1 years.

Overall, 15 patients experienced a relapse at an average of 6.2 years after treatment. This included 8 patients treated with radiotherapy alone, 2 with chemotherapy alone, and 5 with CMT. Of those patients treated with radiotherapy alone, relapse occurred at sites far away from the original tumor.

Overall, 96% of all patients were still alive 5 years later. 86% of all patients were still alive 5 years later without tumor growth or spread. This rate was 93% for patients who had radiation only, and 95% for patients who had combined therapy.

Overall, 11% of patients developed secondary cancers at an average of 4.7 years after treatment. 

This study concluded that radiation therapy and chemotherapy alone or in combination all led to positive long-term outcomes for patients with early-stage NLPHL. The authors suggest that less aggressive therapy may lower the risk of long-term complications for these patients.

This study was retrospective. This means it looked back in time to analyze data. This may limit the conclusions that can be drawn from these results. More studies are needed to confirm these results.