Work

Bmet-08diagnostic Accuracy of Pet, Spect, and Asl in Differentiating Tumor Recurrence From Necrosis in Cerebral Metastasis Post-stereotactic Radiosurgery

Year: 2015

Type: article

Abstract: BACKGROUND AND PURPOSE: Radiographic assessment of cerebral metastasis after stereotactic radiosurgery (SRS) remains a major challenge in neuro-oncology. It is often difficult to distinguish tumor progression (TP) from radiation necrosis (RN) in this setting using conventional MRI. The objective of this study is to compare the diagnostic sensitivity and specificity of different functional imaging modalities for detecting tumor recurrence after SRS. MATERIALS AND METHODS: We retrospectively reviewed patients treated between 2007 and 2010 and identified 14 patients with cerebral metastasis who suffered clinical or radiographic progression following SRS and were imaged with arterial spin labeling (ASL), FDG-PET, and Thallium-SPECT prior to stereotactic biopsy. Diagnostic accuracy, specificity, sensitivity, positive predictive value, and negative predictive value were calculated for each imaging modality using pathologic diagnosis as gold standard. RESULTS: Six patients (42%) suffered tumor progression while eight (58%) developed radiation necrosis. FDG-PET and ASL were equally sensitive in detecting tumor progression (83%). However, the specificity of ASL was superior to the other modalities (100%, 75%, and 50% respectively). Combination of modalities did not augment the sensitivity, specificity, PPV, or NPV of ASL. CONCLUSION: In our series, ASL positivity closely associates with pathological diagnosis of tumor progression after SRS. The sensitivity and specifity of ASL in detecting tumor progression is superior to those of PET and SPECT.

Source: Neuro-Oncology

DOI: 10.1093/neuonc/nov208.08