99mTc-MIBI SPECT in distinguishing neoplastic from nonneoplastic intracerebral hematoma

Distinguishing neoplastic from nonneoplastic intracerebral hematoma has great clinical relevance for the appropriate management of patients. Imaging is not always able to clearly identify a tumor-related intraparenchymal cerebral hemorrhage (ICH), especially in the acute phase, the diagnosis being frequently based on evolution patterns. The aim of this study was to test the value of 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) SPECT as a noninvasive diagnostic tool in early diagnosis of hemorrhagic brain neoplasm. Methods: We prospectively studied 29 patients harboring a nontraumatic acute onset of clinical deterioration caused by ICH with atypical clinical or neuroradiologic features. All patients underwent 99mTc-MIBI SPECT within 48 h from the clinical onset. Early and delayed images were obtained. Both visual and semiquantitative analyses were performed. The 99mTc-MIBI index was obtained from both early and delayed images and the retention index was calculated. Results: In 19 patients (65.5%), a nonneoplastic hemorrhage (15 vascular degenerative diseases, 2 cavernous angiomas, 1 thrombosed middle cerebral artery giant aneurysm, and 1 sinus rectus thrombosis) was diagnosed by clinical and neuroradiologic follow-up or open surgery. In 10 patients (34.5%), a neoplastic hemorrhage (6 metastases, 2 glioblastomas multiforme, 1 ependymoma, and 1 intracranial angioblastic meningioma) was diagnosed by direct histologic typing (open surgery or stereotactic biopsy). In all neoplasm-related hemorrhages, a focal increased tracer uptake was observed in the area of the lesion, whereas no focal increased tracer uptake was noted in all nonneoplastic hematomas. A wide cutoff in the early ratio between neoplastic and nonneoplastic hemorrhages was found. Moreover, a statistically significant difference was found in the delayed ratio (P < 0.01) and the retention index (P < 0.05) between the 2 groups. Conclusion: Our data suggest that 99mTc-MIBI SPECT could play a role in the early noninvasive diagnostic work-up of hemorrhagic brain lesions, allowing a clear differentiation between neoplastic and nonneoplastic ICHs. The high availability and low cost of this nuclear medicine technique can be considered additional advantages.