Abstract
There are limited data regarding the role of 18F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG PET-CT) scanning in primary mediastinal B-cell lymphoma (PMBL). We analyzed 28 patients with PMBL treated with chemotherapy, of whom 25 (89%) also received rituximab and 17 (61%) radiotherapy. PET-CT scans were interpreted using visual analysis and a 5-point scale. After a median follow-up of 2.6 years, four patients relapsed and two died. The 2-year progression-free survival and overall survival were 86% and 94%. PET-CT has excellent negative predictive value (interim, 86–87%; end of treatment, 95%) but limited positive predictive value due to the high frequency of positive scans. Several patients with persistent metabolically active masses underwent biopsies, which showed necrosis but no lymphoma. Thus a negative PET-CT is an excellent predictor of subsequent outcome. However, residual metabolically active masses after treatment should be biopsied to confirm viable lymphoma prior to salvage therapy.
Acknowledgements
This work was funded in part by the Victorian Cancer Agency (grant number CTCB11_18) and the Haematology Society of Australia and New Zealand (New Investigator Scholarship).
Potential conflict of interest
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