RT Journal Article SR Electronic T1 Combined PET and Biopsy Evidence of Marrow Involvement Improves Prognostic Prediction in Diffuse Large B-Cell Lymphoma JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1591 OP 1597 DO 10.2967/jnumed.113.134486 VO 55 IS 10 A1 Juliano J. Cerci A1 Tamás Györke A1 Stefano Fanti A1 Diana Paez A1 José Cláudio Meneghetti A1 Francisca Redondo A1 Monica Celli A1 Chirayu Auewarakul A1 Venkatesh Rangarajan A1 Sumeet Gujral A1 Charity Gorospe A1 Maejoy V. Campo A1 June-Key Chung A1 Tim P. Morris A1 Maurizio Dondi A1 Robert Carr YR 2014 UL http://jnm.snmjournals.org/content/55/10/1591.abstract AB Bone marrow is an important extranodal site in diffuse large B-cell lymphoma (DLBCL), and marrow histology has been incorporated into the new National Comprehensive Cancer Network international prognostic index. Marrow involvement demonstrated histologically confers poor prognosis but is identified by staging PET in more cases. How information from staging PET and biopsy should be combined to optimize outcome prediction remains unclear. Methods: The International Atomic Energy Agency sponsored a prospective international cohort study to better define the use of PET in DLBCL. As a planned subsidiary analysis, we examined the interplay of marrow involvement identified by PET and biopsy on clinical outcomes. Results: Eight countries contributed 327 cases with a median follow-up of 35 mo. The 2-y outcomes of cases with no evidence of marrow involvement (n = 231) were 81% (95% confidence interval [CI], 76%–86%) for event-free survival (EFS) and 88% (83%–91%) for overall survival (OS); cases identified only on PET (n = 61), 81% (69%–89%) for EFS and 88% (77%–94%) for OS; cases indentified only on biopsy (n = 10), 80% (41%–95%) for EFS and 100% for OS; or cases identified by both PET and biopsy (n = 25), 45% (25%–64%) for EFS and 55% (32%–73%) for OS. The hazard ratios for PET-negative/biopsy-negative cases versus PET-positive/biopsy-positive cases were 2.67 (95% CI, 1.48–4.79) for EFS and 3.94 (1.93–8.06) for OS. Conclusion: This large study demonstrates that positive iliac crest biopsy histology only confers poor prognosis for patients who also have abnormal marrow 18F-FDG uptake identified on the staging PET scan. Abnormal 18F-FDG uptake in marrow, when iliac crest biopsy histology is normal, has no adverse effect on outcomes.