In general, the use of combined chemotherapy and low-dose involved-field radiation therapy (LD-IFRT) broadens the spectrum of potential toxicities, while reducing the severity of individual drug-related or radiation-related toxicities. Current approaches use chemotherapy with or without LD-IFRT. The volume of radiation and the intensity/duration of chemotherapy are determined by prognostic factors at presentation, including presence of constitutional symptoms, disease stage, and bulk.
Historically, radiation therapy alone had been the primary treatment for patients with early favorable HL, often after confirmatory negative staging laparotomy. A randomized, prospective trial involving 542 patients with early favorable HL compared MOPP-ABV for three cycles plus involved-field radiation therapy (IF-XRT) with subtotal nodal radiation; with a median follow-up of 7.7 years, combined modality was favored in terms of 5-year event-free survival (98% vs. 74%, P < .001) and 10-year overall survival (97% vs. 92%, P = .001).[Level of evidence: 1iiA] The late mortality from solid tumors, especially in the lung, breast, gastrointestinal tract, and connective tissue, and from cardiovascular disease makes radiation therapy a less attractive option for the best-risk patients, who have the highest probability of cure and long-term survival.[2,3,4,5,6] Recent clinical trials have focused on regimens with chemotherapy and IF-XRT or with chemotherapy alone.
A randomized, prospective trial from the National Cancer Institute of Canada involving 123 patients with early favorable HL compared ABVD for four to six cycles to subtotal nodal radiation; with a median follow-up of 11.3 years, no difference was observed in event-free survival (89% vs. 86%; P = .64) or in overall survival (OS) (98% vs. 98%; P = 0.95).[Level of evidence: 1iiA]
In a randomized study from the Milan Cancer Institute of patients with clinical early-stage HL, 4 months of ABVD followed by either IF-XRT or extended-field radiation therapy (EF-XRT) showed similar OS and freedom-from-progression with a 10-year median follow-up, but the study had inadequate statistical power to determine noninferiority of IF-XRT versus EF-XRT.[Level of evidence: 1iiDii]
The German Hodgkin Lymphoma Study Group (GHSG) randomly assigned 1,190 patients with early favorable HL to the following: