Value of combined approach with thallium-201 single-photon emission computed tomography and Epstein-Barr virus DNA polymerase chain reaction in CSF for the diagnosis of AIDS-Related primary CNS lymphoma

Purpose: To determine the diagnostic capability of thallium-201 ((TI)-T-201) single-photon emission computed tomography (SPECT) combined with Epstein-Barr virus DNA (EBV-DNA) in CSF for the diagnosis of AIDS-related primary CNS lymphoma (PCNSL). Patients and Methods: All human immunodeficiency virus (HIV)-infected patients with focal brain lesions observed between June 1996 and March 1998 underwent lumbar puncture and (TI)-T-201 SPECT. Each CSF sample was tested with polymerase chain reaction (PCR) for EBV-DNA. Results: Thirty-one patients were included, 13 with PCNSL and 18 with nontumor disorders. In 11 PCNSL patients, EBV-DNA was positive. Thallium-201 uptake ranged from 1.90 to 4.07 in PCNSL eases (mean, 2.77; 95% confidence interval [CI], 2.35 to 3.19) and from 0.91 ta 3.38 in nontumor patients (mean, 1.62; 95% CI, 1.30 to 1.94) (P <.0002). Using a lesion/background ratio of 1.95 as cutoff, a negative SPECT was found in one PCNSL case and 16 nonneaplastic cases. A cryprocaccoma and a tuberculoma showed highly increased (TI)-T-201 uptake. Epstein-Barr virus DNA was never detected in nonneaplastic patients. For PCNSL diagnosis, hyperactive lesions showed 92% sensitivity and 94% negative predictive value (NPV), whereas positive EBV-DNA had 100% specificity and 100% positive predictive value. The presence of increased uptake and/or positive EBV-DNA had 100% sensitivity and 100% NPV. Conclusion: Combined SPECT and EBV-DNA showed a very high diagnostic accuracy for AIDS-related PCNSL. Because PCNSL likelihood is extremely high in patients with hyperactive lesions and positive EBV-DNA, brain biopsy could be avoided, and patients could promptly undergo radiotherapy or multimodal therapy. On the contrary, in patients showing hypoactive lesions with negative EBV-DNA, empiric anti-Toxoplasma therapy is indicated. In patients with discordant SPECT/PCR results, brain biopsy seems to be advisable, (C) 1999 by American Society of Clinical Oncology.