Combined positron emission tomography/computed tomography for diagnosis and monitoring of orbital adnexal lymphoma

Purpose Combined whole‐body F‐18‐fluoro‐2‐deoxyglucose positron emission tomography / computed tomography ([18F]FDG‐PET/CT) gives precise information about tumour morphology and metabolism. The standardized uptake value (SUV) allows quantification of tumour metabolism. The diagnostic value of PET/CT in patients with suspected orbital adnexal lymphoma (OAL) was evaluated. Methods Of 21 patients with suspected OAL who underwent combined whole‐body PET/CT between 07/2002 and 11/2016, 16 were scanned before and five after orbital biopsy. Histological tumour determination was performed in all cases via biopsy. Correlation between SUVmax and therapeutic status, lymphoma stage (Ann Arbor classification) and histological grading was tested. Results All lesions could be depicted by combined whole‐body PET/CT. Histology confirmed two malignant T‐cell and 18 malignant B cell non‐Hodgkin lymphomas as well as one patient suffering from systemic lymphoma with chronic polypoid sinusitis. SUVmax levels of orbital findings were significantly lower after therapy (p