Utility of bone marrow biopsy at diagnosis in pediatric Hodgkin's lymphoma.

BACKGROUND: Bone marrow biopsy is considered essential for the staging and risk-adapted treatment of Hodgkin's lymphoma with unfavorable risk features. We reviewed the cases of pediatric Hodgkin's lymphoma in our institution to determine the impact of bone marrow involvement on treatment, relapse, and survival. DESIGN AND METHODS: We reviewed the clinical characteristics and outcome of 383 patients treated for Hodgkin's lymphoma at St. Jude Children's Research Hospital between August 1990 and August 2008. The 5-year survival estimates for patients with and without bone marrow involvement were compared. RESULTS: Of 228 patients who had a bone marrow biopsy at diagnosis, 21 had bone marrow involvement. Bone marrow findings changed the disease stage in only seven patients (3.1%): from IB to IVB (n=1), from IIA (with bulky disease) to IVA (n=1), from IIB to IVB (n=1), and from IIIB to IVB (n=4). One patient's risk assignment changed from intermediate to unfavorable risk without his chemotherapy being altered. No statistically significant difference was observed between patients with stage IV Hodgkin's lymphoma who did (n=21) and did not (n=61) have bone marrow involvement in 5-year relapse-free survival (89.6± 7% versus 73.9±6.1%; P=0.25) or 5-year overall survival (95.2±8.2% versus 87.3±4.9%; P=0.82). CONCLUSIONS: Although bone marrow involvement changed the stage in 3.1% of pediatric Hodgkin's lymphoma patients, it did not change risk-adapted treatment or prognosis. We conclude that bone marrow biopsy need not be performed at diagnosis in patients who have unfavorable risk features, although this finding should be confirmed by larger prospective studies.

Comparison of gallium and PET scans at diagnosis and follow-up of pediatric patients with Hodgkin lymphoma.

BACKGROUND: Positron emission tomography (PET) and gallium scans facilitate diagnosis and staging, evaluation of response to therapy, and monitoring for relapse in Hodgkin lymphoma (HL), but have not been compared in pediatric HL. PROCEDURE: We performed concurrent PET and gallium scans on 44 pediatric HL patients at diagnosis, early response, off chemotherapy, and off-therapy evaluations. PET and gallium scans were compared to each other and to computed tomography (CT) alone to determine whether either modality led to a change in stage or modified the results of the early response evaluation, which was used to determine the radiation dose. RESULTS: PET upstaged four patients at diagnosis (2 from stage I to II, one II to III, and one III to IV), but did not lead to a change in therapy in any of them. It changed response category in two patients at early response evaluation, leading to a change in radiation dose for 1 patient (25.5 Gy instead of 15 Gy to the spleen). Gallium did not change the stage of treatment for any patient. The negative predictive values for eventual lymphoma relapse of PET and gallium scans at off therapy were 89% and 83%, respectively; the positive predictive value of PET at off therapy is 29%. CONCLUSION: PET appears to be superior to gallium in pediatric HL; future studies will determine the optimal timing of PET to assess early response and the utility of quantitative interpretation of the avidity of specific nodal sites.