Comparison of thallium-201 uptake and retention indices for evaluation of brain lesions with SPECT

Usefulness of dual isotope 123I-IMP and 201Tl SPECT for the diagnosis of primary central nervous system lymphoma and glioblastoma

BACKGROUND

Preoperative differential diagnosis between primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) is important because these tumors require different surgical strategies. This study investigated the usefulness of dual isotope, iodine-123-labeled N-isopropyl-p-iodo-amphetamine (¹²³I-IMP) and thallium-201 chloride single-photon emission computed tomography (²⁰¹Tl SPECT) for the differential diagnosis.

METHODS

Twenty-five PCNSL patients and 27 GBM patients who underwent dual isotope imaging, ¹²³I-IMP and ²⁰¹Tl SPECT, are included. Tumor-to-normal (T/N) ratio was calculated from the ratio of maximum tracer counts in the lesion to the mean counts in the contralateral cerebral cortex. The mean and minimum apparent diffusion coefficient values (ADC_mean and ADC_min, respectively) on magnetic resonance imaging were also analyzed.

RESULTS

Delayed phase ¹²³I-IMP SPECT was the most useful imaging examination for the differentiation between PCNSL and GBM compared with early phase ¹²³I-IMP SPECT, early and delayed phase ²⁰¹Tl SPECT, ADC_mean, and ADC_min. However, the median T/N ratios of PCNSL and GBM were 1.32 and 0.83, respectively, in the delayed phase ¹²³I-IMP SPECT. On the other hand, the median T/N ratios of PCNSL and GBM were 3.10 and 2.34, respectively, in the delayed phase ²⁰¹Tl SPECT, with excellent tumor detection.

CONCLUSION

Delayed phase ¹²³I-IMP SPECT could differentiate between PCNSL and GBM with high accuracy, but T/N ratio was low and tumor detection was poor. ²⁰¹Tl SPECT was useful for estimation of the malignancy and localization of the tumors with high T/N ratio. Dual isotope ¹²³I-IMP and ²⁰¹Tl SPECT was useful for the preoperative diagnosis of PCNSL and GBM.

Increasing feasibility and utility of (18)F-FDOPA PET for the management of glioma

INTRODUCTION

Despite radical treatment therapies, glioma continues to carry with it a uniformly poor prognosis. Patients diagnosed with WHO Grade IV glioma (glioblastomas; GBM) generally succumb within two years, even those with WHO Grade III anaplastic gliomas and WHO Grade II gliomas carry prognoses of 2-5 and 2 years, respectively. PET imaging with (18)F-FDOPA allows in vivo assessment of the metabolism of glioma relative to surrounding tissues. The high sensitivity of (18)F-DOPA imaging grants utility for a number of clinical applications.

METHODS

A collection of published work about (18)F-FDOPA PET was made and a critical review was discussed and written.

RESULTS

A number of research papers have been published demonstrating that in conjunction with MRI, (18)F-FDOPA PET provides greater sensitivity and specificity than these modalities in detection, grading, prognosis and validation of treatment success in both primary and recurrent gliomas. In further comparisons with (11)C-MET, (18)F-FLT, (18)F-FET and MRI, (18)F-FDOPA has shown similar or better efficacy. Recently synthesis cassettes have become available, making (18)F-FDOPA more accessible.

CONCLUSIONS

According to the available data, (18)F-FDOPA PET is a viable radiotracer for imaging and treatment planning of gliomas.

ADVANCES IN KNOWLEDGE AND IMPLICATION FOR PATIENT CARE

(18)F-FDOPA PET appears to be a viable radiopharmaceutical for the diagnosis and treatment planning of gliomas cases, improving on that of MRI and (18)F-FDG PET.

Voxel-based analysis of (201)Tl SPECT for grading and diagnostic accuracy of gliomas: comparison with ROI analysis

Purpose

The aim of this retrospective study was to assess the utility of a voxel-based analysis (VBA) method for ²⁰¹Tl SPECT in glioma, compared to conventional ROI analysis.

Methods

We recruited 24 patients with glioma (high-grade 15; low-grade 9), for whom pre-operative ²⁰¹Tl SPECT and MRI were performed. SPECT images were coregistered with MRI. The uptake ratio (UR) images of tumor to contralateral normal tissue were measured on early and delayed images, and the ²⁰¹Tl retention index (RI) map was calculated from the early and delayed uptake ratio maps. In the ROI analysis, tumors were traced on a UR map, and the mean and maximal uptake ratio values on the early images were, respectively, defined as the mean and maximal UR. The mean and maximal RI values (mean and maximal RI) were calculated by division of the mean and maximal UR, respectively, on the delayed image by the mean and maximal UR on the early image. For the RI map calculated voxel by voxel, the maximal RI value was defined as VBA-RI. We evaluated sensitivity and accuracy of differential analysis with the mean and maximal UR, RI, and VBA-RI.

Results

The high- and low-grade groups showed no significant difference in mean and maximal RI (0.98 ± 0.12 vs. 1.05 ± 0.09 and 0.98 ± 0.18 vs. 1.05 ± 0.14, respectively). The AUC and accuracy of the mean and maximal RI were 0.681 and 66.7 %, and 0.622 and 62.5 %, respectively. In contrast, VBA-RI was higher in high-grade than in low-grade glioma (1.69 ± 0.27 vs. 0.68 ± 0.66, p < 0.001). The AUC and accuracy of VBA-RI were 0.963 and 95.8 %, which are higher than those obtained for mean (p < 0.05) and maximal RI (p < 0.01). There was no significant difference in ROC between the VBA-RI and the mean UR (0.911, p = 0.456) and maximal UR (0.933, p = 0.639); however, the AUC, sensitivity, and diagnostic accuracy of VBA-RI were all higher than those of the mean and maximal UR.

Conclusion

The voxel-based analysis method of ²⁰¹Tl SPECT may improve diagnostic performance for gliomas, compared with ROI analysis.

Brain Metastases from Different Primary Carcinomas: an Evaluation of DSC MRI Measurements

This study evaluated the roles of different dynamic susceptibility contrast magnetic imaging (DSC MRI) measurements in discriminating between brain metastases derived from four common primary carcinomas. Thirty-seven patients with brain metastases were enrolled. Relative cerebral blood volume (rCBV), cerebral blood flow (rCBF) and relative mean transit time (rMTT) in both tumor and peritumoral edema were measured. Metastases were grouped by their primary tumor (lung, gastrointestinal, breast and renal cell carcinoma). DSC MRI measurements were compared between groups. Mean rCBV, rCBF, rMTT in tumor and peritumoral edema of all brain metastases (n=37) were 2.79 ± 1.73, 2.56 ± 2.11, 1.21 ± 0.48 and 1.05 ± 0.53, 0.86 ± 0.40, 1.99 ± 0.41, respectively. The tumoral rCBV (5.26 ± 1.89) and rCBF (5.32 ± 3.28) of renal metastases were greater than those of the other three metastases (P<0.05). The tumoral rMTT (1.58 ± 0.77) of breast metastases was statistically greater than that (0.96 ± 0.31) of gastrointestinal metastases (P=0.013). No statistical difference was found between peritumoral rCBV, rCBF and rMTT (P>0.05). Evaluating various DSC MRI measurements can provide complementary hemodynamic information on brain metastases. The tumoral rCBV, rCBF and likely rMTT can help discriminate between brain metastases originating from different primary carcinomas. The peritumoral DSC MRI measurements had limited value in discriminating between brain metastases.

Thallium-201SPECT assessment in the detection of recurrences of treated gliomas and ependymomas

INTRODUCTION

The aim of this study was to establish the value of thalium-(201) single-photon emission computed tomography ((201)Tl-SPECT) in the detection of recurrences in the follow-up of patients with treated primary neuroepithelial tumours.

MATERIAL AND METHODS

Sixty-three (201)Tl-SPECT were performed in 36 patients with glioma (12 males, mean age of 46 +/- 13 years). All patients underwent surgery and adjuvant radiotherapy (and some of them received chemotherapy). All patients were submitted to morphological neuroimaging techniques as well (and (201) Tl-SPECT). Mean follow-up was 18.3 +/- 14.6 months. Gold standard was based on clinical follow-up, therapeutical decisions (at least 4 months after (201)Tl-SPECT) and imaging features.

RESULTS

Sensitivity and specificity of (201)Tl-SPECT to detect glioma recurrences were 90% and 100% respectively and 93% accuracy. Sensitivity and specificity for high grade tumours, were 100% respectively. Due to 4 false negatives, sensitivity and specificity for low grade gliomas were 78% and 100%. In the positive (201)Tl-SPECT group of patients overall survival was 13.64% at the end of the study. The negative (201)Tl-SPECT group had 84.62% overall survival at the end of the study (p = 0.0003). CONCLUSIONS. (201)Tl-SPECT is a valuable and noninvasive diagnostic procedure to detect recurrence or progression disease for treated gliomas and ependymomas. (201)Tl-SPECT has a good correlation with short term prognosis with excellent diagnostic accuracy.

Early dynamic 201Tl SPECT in the evaluation of brain tumours

OBJECTIVE

To estimate the usefulness of early dynamic 201Tl single photon emission computed tomography (SPECT) studies in distinguishing the histological malignancy of brain tumours.

METHODS

Dynamic 201Tl SPECT was performed for 3 min per scan for 15 min immediately after the administration of 201TlCl in 110 patients with brain tumours (111 lesions). The data obtained each 3 min were used for dynamic SPECT, and the five sets of data obtained were added to acquire static SPECT data. For static SPECT, the static thallium index (STI) was calculated as the ratio of 201Tl uptake in the tumour to that of the contralateral normal brain. The ratio of the 201Tl uptake for each 3 min was defined as the dynamic thallium index (DTI). The dynamic thallium rate (DTR), as a per cent, was calculated as DTR=(DTI for every 3 min)/STI H 100. The five values were approximated as a linear function and the slope (%/min) was calculated.

RESULTS

In static SPECT, there was no significant difference between the STI of malignant tumours (glioblastoma and anaplastic astrocytoma) and that of benign tumours (low-grade glioma, meningioma, pituitary adenoma, neurinoma and haemangioblastoma) (3.7+/-1.5, 5.0+/-3.5, respectively). On dynamic SPECT, DTI increased markedly over 15 min for malignant tumours. In contrast, the DTI of benign tumours increased slightly, steadily or decreased. The slope of the linear functions calculated from the DTRs was much higher in the malignant tumour group than in the benign tumour group (P<0.001).

CONCLUSIONS

We suggest that the performance of 201Tl dynamic SPECT for 15 min is useful for distinguishing malignant brain tumours from benign brain tumours and reduces the examination stress of patients.

Neuroimaging of Metastatic Brain Disease

This review discusses imaging techniques for the diagnosis, treatment, and monitoring of brain metastases. It assesses the various modalities on the basis of their respective advantages and limitations. Recent advances in imaging technologies provide evaluation that is more accurate for tumor localization, morphology, physiology, and biology. When used in combination, these technologies provide clinicians with a powerful diagnostic and prognostic tool for managing metastatic brain disease.

Usefulness of Thallium-201 Chloride Single Photon Emission Computed Tomography for the Preoperative Diagnosis of Fourth Ventricle Meningioma-Case Report-

A 51-year-old woman presented with a fourth ventricle meningioma manifesting as a 2-week history of dizziness and vomiting. Computed tomography (CT) and magnetic resonance (MR) imaging revealed a round mass lesion in the fourth ventricle. Thallium-201 chloride single photon emission computed tomography (201TlCl SPECT) showed high and rapid uptake on the early image and rapid washout on the delayed image. The preoperative diagnosis of meningioma could be established based on these findings. Total removal of the tumor was successfully performed. 201TlCl SPECT is useful for the preoperative diagnosis of fourth ventricle meningioma combined with CT, MR imaging, and angiography.