Top Line: Despite myriad de-escalation attempts, low-dose radiation remains a mainstay of achieving superb outcomes for early-stage Hodgkin lymphoma.
The Study: In the COG AHOD0431 trial, 278 patients younger than age 21 with Stage IA or IIA Hodgkin lymphoma received 3 cycles of AVPC (doxorubicin, vincristine, prednisone, and cyclophosphamide) followed by involved-field radiation to 21 Gy on if there was residual disease on PET. Patients also had a PET after the first cycle, and this secondary analysis asks if residual disease at this extremely early time point is telling of relapse rates. Among those with no residual disease after one cycle of chemo (56%) progression-free survival (PFS) at 10 years was 97% with radiation versus 84% without. Among those with residual disease after one cycle of chemo (46%), PFS at 10 years was 81% with radiation versus 64% without. What’s more, 28 of 30 relapses after no radiation were within initial PET-avid disease versus 5 of 10 relapses after radiation. This once again demonstrates the power of low doses of radiation to alter the overall disease course by slashing the risk of recurrence at sites of original disease.
TBL: Low risk, early stage pediatric HL patients with residual disease after 1 cycle of chemo have an increased risk of recurrence (particularly at sites of PET+ disease) that is improved with 21 Gy consolidative radiation. | Parekh, Blood 2022