The impact of involved field radiation therapy in the treatment of relapsed or refractory non-Hodgkin lymphoma with high-dose chemotherapy followed by hematopoietic progenitor cell transplant

Patients with refractory/relapsed non-Hodgkin lymphoma (NHL) often receive high-dose chemotherapy (HDCT) followed by hematopoietic progenitor cell transplant (HPCT) as salvage therapy. We examined the role of involved field radiation therapy (IFRT) in this setting. The records of 167 patients with refractory/relapsed NHL who underwent HDCT followed by HPCT between February 1990 and November 2003 were reviewed. Fifty-three patients received IFRT and 114 did not receive IFRT in the peritransplant period. Eighty patients were alive at the time of analysis with a median follow up for alive patients of 4.5 years in the no IFRT group and 4.2 years in the IFRT group (P = 0.53). Patients undergoing IFRT were more likely to have bulky (P = 0.02) and extranodal (P= 0.04) disease at initial diagnosis. There was no significant difference between the treatment groups regarding mortality in the first 100 days after HPCT (P = 0.31). Five-year overall survival rates were 46.7% for the no IFRT group and 40.0% for the IFRT group (P= 0.15). Disease-free survival was significantly worse for patients receiving IFRT (P = 0.02); however, when considering local control, the addition of IFRT resulted in a 5-year rate similar to that for patients who did not receive IFRT (68.6% vs. 72.0% respectively, P= 0.73). Although disease-free survival was inferior in patients who received IFRT, despite more adverse clinical features the use of IFRT resulted in similar rates of local control and overall survival compared with those who did not receive IFRT. The use of IFRT was not associated with an increase in the risk of acute mortality or late events.