Delayed [(18)F]FDG PET imaging of central nervous system lymphoma: is PET better than MRI?

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Delayed [

F]FDG PET imaging of central nervous system lymphoma: is PET better than MRI?

Christian Jeanguillaume¹, Gilles Metrard¹, Hervé Rakotonirina¹, Olivier Morel¹, Cécile Berthelot¹, Tanguy Blaire¹, Francis Bouchet¹, Sylvie Giraud¹, Franck Lacoeuille¹, Aurélie Cahouet¹, Malgorzata Truchan-Graczyk²,

Charles Foussard², Jean Jacques Lejeune¹

1Service de médecine nucléaire, Centre Hospitalier d’Angers 49933 Angers Cedex 9, France

2Service des maladies du sang, Centre Hospitalier d’Angers Angers, France

Received: 10 March 2006 / Accepted: 26 March 2006 / Published online: 19 July 2006

© Springer-Verlag 2006

Eur J Nucl Med Mol Imaging (2006) 33:1370–1371 DOI 10.1007/s00259-006-0143-1

The use of [¹⁸F]FDG PET in primary central nervous system lymphoma was the subject of a recent article in this journal [1]. The authors concluded that MRI plays a crucial role in CNS lymphoma, but that [¹⁸F]FDG PET could yield additional information. It is well known that the use of [¹⁸F]FDG to study brain tumour is hindered by the high glucose affinity for the grey matter. Recently, Spence [2]

proved that delayed imaging of brain tumours could enhance the tumour to background contrast. In our institution we currently perform early (1 h post injection) and late (6 h) images for every patient with suspected malignant brain disease.

This 73-year-old woman was referred for the evaluation of relapse of a diffuse large B-cell lymphoma initially localised in the abdomen and bone (T3–T11). She was treated with apparent success with six courses of R- MBACOD [rituximab (Mabthera, Rituxan)–methotrexate, bleomycin, adriamycin, cyclophosphamide, oncovin, dexa- methasone]. Ten months later, the patient experienced numbness of her right arm and a cerebellar syndrome. MRI revealed a tumour in the cerebellum, and a possible second lesion in the right part of the tentorium cerebelli. A PET scan was performed 14 days thereafter, using 350 MBq [¹⁸F]FDG. For early acquisition, scanning was performed in seven bed positions, at 4 min per bed position, in 2D mode using a GE Discovery ST. The late acquisition

consisted of a 45 min bed position in 3D mode. Figurea shows the maximum intensity projection (MIP) image of the brain in the early phase. Thoracic and abdominal examination did not reveal any abnormality. Figure b shows the late MIP image. The tomogram (c) confirmed the three lesions suspected on MIP imaging, in the left cerebellum, left temporal pole and right tentorium cerebel- li. A small lesion at the anterior edge of the right cerebellum could also be suspected. The use of [¹⁸F]FDG PET in CNS Lymphoma has already been advocated, but most of these articles used only early imaging [1, 3–6].

Christian Jeanguillaume ()) Service de médecine nucléaire, Centre Hospitalier d’Angers, 49933 Angers Cedex 9, France e-mail: [email protected]

European Journal of Nuclear Medicine and Molecular Imaging Vol. 33, No. 11, November 2006

Although recurrent lymphoma lesions are more clearly visible than primary ones, this case suggests that dual- phase [¹⁸F]FDG PET may play an increasing role in the management of CNS lymphoma.

References

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correlation with MRI and clinical follow-up. Eur J Nucl Med Mol Imaging 2006;33(2):164–8

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European Journal of Nuclear Medicine and Molecular Imaging Vol. 33, No. 11, November 2006