Diagnostic performance of SPECT-CT imaging in unilateral condylar hyperplasia.

Nuclear imaging plays an important role in the diagnostic path of patients with unilateral condylar hyperplasia (UCH). The purpose of this study was to determine the performance of single-photon emission computed tomography-computed tomography (SPECT-CT) in a large group of patients with suspected UCH. This study prospectively included 156 patients with a clinical presentation of progressive mandibular asymmetry. All patients underwent 99 mTc-HDP SPECT-CT and extensive baseline and follow-up documentation. The relative activity of the ipsilateral condyle in relation to the contralateral condyle was calculated for both the mean and maximum count, and the diagnostic accuracy of different cut-off values was determined. The area under the receiver operating characteristic curve of the SPECT-CT scan was 0.892 for the mean count and 0.873 for the maximum count. The optimal cut-off of> 8% (SPECT-CT mean count) resulted in a sensitivity of 87.0% and a specificity of 88.6%. SPECT-CT showed good diagnostic performance in UCH; however the benefit of the CT scan is questionable and the potential disadvantages have to be weighed against the benefits when compared to standard SPECT scanning. When using SPECT-CT in the diagnostic path in UCH, a mean value cut-off of>8% for the relative activity between the condyles is most accurate.

Lack of perfusion enhancement after administration of nicotinamide and carbogen in patients with glioblastoma: a 99mTc-HMPAO SPECT study.

BACKGROUND: Nicotinamide (NAM) and carbogen both have been shown to enhance the radiation effect in rodent tumour models and are currently being tested in clinical trials. These agents have demonstrated to act against hypoxia and one of their underlying mechanisms could be an increase of tumour blood perfusion. PURPOSE: To analyse the effect of both agents on normal brain perfusion and tumour perfusion in patients with glioblastoma. MATERIALS AND METHODS: Nineteen patients with glioblastoma were studied with 99mtechnetium-hexamethylpropyleneamine oxime single photon emission computed tomography (99mTc-HMPAO SPECT) before and after administration of carbogen and/or NAM. Another six patients were studied with the same procedure but without any flow modulator and were used as controls. RESULTS: Although the variations between patients were large, no significant enhancement in mean tumour and normal brain perfusion could be demonstrated with NAM or carbogen compared to the control patients. Also no consistent changes in the mean perfusion ratio between tumour and surrounding normal brain were found, suggesting an absence of a selective perfusion effect. CONCLUSIONS: No significant influence of carbogen and/or NAM on tumour perfusion and normal brain perfusion could be detected with SPECT in patients with glioblastoma.