Curative radiotherapy for laparotomy-staged IA, IIA, IIIA Hodgkin's disease: An evaluation of the gains achieved with radical radiotherapy

Between 1970 and 1983, 179 patients with pathologically staged IA, IIA, and IIIA Hodgkin's disease were treated with curative radiotherapy. From 1970 to 1974, patients were treated with standard extended or total nodal field irradiation (Treatment Group 1). Since 1975, because of the high prevalence of recurrences in patients with large mediastinal mass and/or hilar disease and/or splenic involvement (LMM &/or H+ &/or S+), treatment was modified to include low-dose lung irradiation within the mantle field for those patients with LMM &/or H+ and low-dose liver irradiation within the infradiaphragmatic field for patients with S+ (radical XRT). Patients who did not have those characteristics were treated with standard radiotherapy (standard XRT). A total of 122 patients were treated from 1975 to 1983 (Treatment Group 2), of whom 61 received radical XRT and 61 received standard XRT. An analysis was done to evaluate whether the progressive improvement in outcome since 1970 at the University of Minnesota Hospital resulted from the contribution of modified treatment or from progressive improvement in treatment overall. There was a statistical improvement in recurrence-free survival (RFS) in Treatment Group 2 (Tr Gr 2) compared to Treatment Group 1 (Tr Gr 1), with 10-year RFS of 80% versus 57% (p < 0.001 for time to event). The improvement in RFS was attributed to treatment modification consisting of radical XRT for those patients with LMM &/or H+ &/or S+. There was no change in RFS for those patients without LMM &/or H+ &/or S+ who were treated in Tr Gr I and Tr Gr 2, with 10-year RFS of 78% versus 86% (p = 0.29), respectively. However, treatment results for patients with LMM &/or H+ &/or S+ improved considerably in the radical XRT group. Comparing standard versus radical XRT, 10-year RFS was 36% versus 78% (p = 0.001), and 10-year OS was 72% versus 92% (p = 0.034). Patterns of relapse also changed for patients with LMM &/or H+ &/or S+ who were treated with radical XRT. Rather than showing a high frequency of intrathoracic recurrence as was seen in those patients with LMM &/or H+ &/or S+ after standard XRT, the relapse pattern was similar to patients without LMM &/or H+ &/or S+. Salvage treatment was well tolerated for patients who failed after radical XRT. Delayed, life-threatening effects, such as pulmonary and cardiovascular complications and SMN, were equivalent for patients in Tr Gr 1 versus 2, and for those who received standard and radical XRT. These data clearly indicate that significant therapeutic gains in patients with LMM &/or H+ &/or S+ resulted from the use of radical XRT, without an increase in side effects and/or delayed, life-threatening complications.