Response to initial chemotherapy

The rapidity of response to initial cycles of chemotherapy also appears to be prognostically important.[43-45] Response evaluation in previous generations of trials relied on computed tomography and gallium uptake; positron emission tomography (PET) scanning is now routinely used to assess early response in pediatric Hodgkin lymphoma.[46] Fluorine F 18-fludeoxyglucose PET avidity after two cycles of chemotherapy (PET2) for Hodgkin lymphoma in adults has been shown to predict treatment failure and progression-free survival.[47-49] Reduction in PET avidity after one cycle of chemotherapy was associated with a favorable EFS outcome in children with limited-stage classical Hodgkin lymphoma.[39] Additional studies in children are ongoing to assess the role of early PET-based response in modifying therapy and predicting outcome.

Prognostic factors will continue to change because of risk stratification and choice of therapy, with parameters such as disease stage, bulk, systemic symptomatology, and early response to chemotherapy used to stratify therapeutic assignment.