Prognostic value of chest x-ray- and CT-defined large mediastinal adenopathy in high-risk pediatric Hodgkin lymphoma: A report from the Children's Oncology Group Study AHOD0831.

Abstract

We compared the prognostic value of chest radiograph (CXR)- and computed tomography (CT)-derived definition of large mediastinal adenopathy (LMA) in pediatric Hodgkin lymphoma (HL). Total 143 patients treated for stage IIIB/IVB HL on COG AHOD0831 were included in this study. Six definitions of LMA were investigated: (i) mediastinal mass ratio on CXR (MRCXR )>1/3; (ii) mediastinal mass ratio on CT (MRCT )>1/3; (iii) mediastinal mass volume on CT (MVCT )>200mL; (iv) normalized mediastinal mass volume (MVCT /thoracic diameter [TD])>1mL/mm; (v) mediastinal mass diameter on CT (MDCT )>10cm; and (vi) normalized mediastinal mass diameter (MDCT /TD)>1/3. Median age at diagnosis was 15.8years (range: 5.2-21.3years). In patients with a slow early response (SER) to chemotherapy, MVCT >200mL, MDCT >10cm, and MDCT /TD>1/3 were associated with worse relapse-free survival (RFS) on MVA, while MRCXR >1/3, MRCT >1/3, and MVCT /TD>1mL/mm trended toward worse RFS; MDCT /TD was the most strongly prognostic for inferior RFS, with a hazard ratio of 6.41 for MDCT /TD>1/3 versus ≤1/3 on MVA (p=.02). LMA according to MVCT >200mL, MDCT >10cm, and MDCT /TD>1/3 is associated with poor prognosis in advanced-stage HL patients with SER. The normalized mediastinal diameter, MDCT /TD>1/3 appears to be the strongest predictor of inferior RFS.