The utility and limitations of ¹⁸F-fluorodeoxyglucose positron emission tomography with computed tomography in patients with primary mediastinal B-cell lymphoma: single institution experience and literature review

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.

Keywords::

• Primary mediastinal B-cell lymphoma
• PET-CT
• interim PET-CT
• prognostic factors
• risk adapted therapy
• non-Hodgkin lymphoma

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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