[The second trial that I wanted to mention was conducted in India. The distribution of histologic types of Hodgkin disease there is different from what is seen in the US, so this information is less relevant to our case. Full citation is given below
Laskar S, et al. Consolidation radiation after complete remission in Hodgkin's disease following six cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine chemotherapy: is there a need? J Clin Oncol. 2004 Jan 1;22(1):62-8.
This is a randomized trial of ABVD-alone (6 cycles) versus ABVD-plus-radiotherapy. Patients with bulky disease were not excluded.
The ABVD-alone group included 44 patients with stages I-II. The ABVD-plus-radiotherapy group included 55 patients with stages I-II.
Event free survival (no recurrence or death from any causes) at 8 years was 94% in the ABVD-alone group and 97% in the ABVD-plus-radiotherapy group.
Interestingly, for more advanced stages (III-IV) radiotherapy showed more clear evidence of protective effect. The event-free survival at 8 years was 59% in the ABVD-alone group and 78% in the ABVD-plus-radiotherapy group (but this is not relevant to our case).]