XVII. Radiotherapy in early stage Hodgkin lymphoma.

The treatment of patients with Hodgkin lymphoma (HL) is one of the major success stories in oncology and 60–90% of patients are cured of their malignancy depending on clinical stage and risk factors. Radiotherapy was used to cure patients with HL as early as the 1940s, but more widespread successes came in the 1960s for early stage diseases I A and II A with the use of extended field radiotherapy (RT) techniques to include all nodal stations above the diaphragm such as the ‘mantle’ field [1]. Recurrence of disease outside the radiation field in some patients led to studies of adjuvant chemotherapy as part of a combined modality approach. These studies led to improved progression free survival (PFS) but no overall survival (OS) advantage was seen over RT alone because patients developing recurrent disease after RT were very efficiently salvaged by chemotherapy [2]. A sequential and thorough approach in large randomized trials exemplified by the German Hodgkin Study Group (GHSG) has led to substantial treatment reduction and established a standard of care based on minimal highly effective combined modality treatment (CMT). With a median follow-up of 7.5 years, 8-year results of the GHSG HD10 trial involving 1370 patients with early stage favourable HL showed that two cycles of chemotherapy regimen consisting of Adriamycin, Cyclophosphamide, Oncovin, Procarbazine, Prednisolone (ABVD) and 20Gy of involved field radiotherapy (IFRT) were as effective as four cycles ABVD and 30 Gy, produced less immediate toxicity and resulted in an OS of 95% and freedom from treatment failure and event-free survival of 86% [3]. For early stage unfavourable HL, moderate dose escalation using a chemotherapy regimen consisting of Bleomycin, Etoposide, Adriamycin, Cyclophosphamide, Oncovin, Procarbazine and Prednisone (BEACOPP) did not significantly improve outcome over four cycles of ABVD and 30 Gy IFRT, which the GHSG HD11 concluded remains the standard of care [4] Whilst efforts to improve a 5-year Failure From Treatment Failure (FFTF) of 85% and OS of 94.5% are ongoing in unfavourable disease, it will be difficult to improve the results of two cycles of ABVD and 20 Gy for the favourable