F-18 FDG PET-CT for predicting survival in patients with recurrent glioma: a prospective study.

INTRODUCTION: Recurrent gliomas are usually histologically high grade; either due to recurrence of a de novo high-grade primary or anaplastic transformation in case of low-grade tumors. Survival in these patients is variable. The objective of the present study is to evaluate the role of FDG PET-CT for predicting survival in a large group of patients with suspected recurrent glioma. METHODS: A total of 81 previously treated histopathologically proven glioma patients; with clinical and conventional imaging findings suspicious of recurrence were included in this study. All patients underwent FDG PET-CT study. Based on tumor to white matter (T/W) and tumor to grey matter (T/G) ratios, all lesions were scored on PET-CT (PET scores 0, 1 and 2). Patients were followed up clinically and by repeated imaging. Data was censored, if the patient died of disease or at the end of the study. Survival analysis was done for each variable employing univariate analysis followed by multivariate analysis, using variables found significant on univariate analysis. RESULTS: PET score was found to be the most significant predictor of survival in univariate and multivariate analysis (p 0.003). Patients having PET score 2 had poorer survival compared to both PET score 0 (p 0.001) and PET score 1 (p 0.004). Other covariates found to have significant correlation with survival were primary treatment modality and clinical symptoms at the time of recurrence. CONCLUSION: FDG uptake on PET-CT is a strong predictor of survival in patients with suspected recurrent glioma.

Use of 99m-technetium-glucoheptonate as a tracer for brain tumor imaging: An overview of its strengths and pitfalls.

Brain tumors represent a vexing clinical problem in oncology due to their increasing incidence, difficulties in treatment and high rates of recurrence. It is especially challenging to evaluate the posttreatment disease status because differentiation of recurrence from treatment-induced changes (radiation necrosis) is not possible with the use of magnetic resonance imaging, the most commonly used imaging method in this setting. Various functional imaging methods, including positron emission tomography and single photon emission computed tomography (SPECT) have been employed in this context. SPECT with 99m-technetium (99mTc)-glucoheptonate (GHA) has shown promising results for differentiation of recurrent brain tumor from radiation necrosis. In this review, we have discussed in details the basics of 99mTc-GHA SPECT imaging in brain tumor along with the available literature in this regard.

Brain perfusion single photon emission computed tomography in major psychiatric disorders: From basics to clinical practice.

Brain single photon emission computed tomography (SPECT) is a well-established and reliable method to assess brain function through measurement of regional cerebral blood flow (rCBF). It can be used to define a patient's pathophysiological status when neurological or psychiatric symptoms cannot be explained by anatomical neuroimaging findings. Though there is ample evidence validating brain SPECT as a technique to track human behavior and correlating psychiatric disorders with dysfunction of specific brain regions, only few psychiatrists have adopted brain SPECT in routine clinical practice. It can be utilized to evaluate the involvement of brain regions in a particular patient, to individualize treatment on basis of SPECT findings, to monitor the treatment response and modify treatment, if necessary. In this article, we have reviewed the available studies in this regard from existing literature and tried to present the evidence for establishing the clinical role of brain SPECT in major psychiatric illnesses.

(99m)Tc-hexamethyl propyleneamine oxime brain perfusion single photon emission computed tomography in characterization of dementia: an initial experience in Indian clinical practice.

There is a growing health burden in developing countries due to recent trends of increasing incidence of neurodegenerative diseases. To reduce the healthcare cost and effective management of dementia illness, early diagnosis, accurate differentiation and their progression assessment is becoming crucially important. We are utilizing (99m)Tc-d, l-hexamethyl propyleneamine oxime (HMPAO) brain perfusion single photon emission computed tomography (SPECT) to characterize dementia on the basis of perfusion patterns and observed significant improvement in their management. Eleven patients (median age of 60 years range of 53-83 years) with clinical suspicion of dementia underwent (99m)Tc-HMPAO brain perfusion SPECT. SPECT-computed tomography acquisition done, data are reconstructed, reviewed in three view and further processed in "neurogam" to get voxel based analysis and the comparison with age based normal database and surface mapping. Final diagnosis was done with clinical correlation. Four patients are diagnosed as Alzheimer's disease, two as frontotemporal dementia, one as dementia of Lewy bodies, two as vascular dementia and two as pseudodementia. All imaging findings are well-correlated with clinical background. Brain perfusion SPECT with HMPAO was very helpful to us in characterizing the patients of dementia by its perfusion pattern.

F-18 FDG PET-CT in patients with recurrent glioma: comparison with contrast enhanced MRI.

PURPOSE: The purpose of the study was to compare the efficacies of FDG PET-CT and contrast enhanced MRI in detection of recurrent gliomas. METHODS: Ninety histopathologically proven glioma patients with clinical suspicion of recurrence were evaluated. All patients underwent FDG PET-CT scan and contrast enhanced MRI. Combination of clinical follow up, repeat imaging and biopsy (when available) was taken as gold standard. RESULTS: Based on gold standard criteria, 59 patients were positive and 31 patients were negative for recurrence. Overall sensitivity and specificity of FDG PET-CT were 70% and 97% respectively whereas that for contrast enhanced MRI was 95% and 23%. FDG PET-CT also has higher accuracy (80%) as compared to MRI (70%). FGD PET-CT has lower sensitivity than MRI in all grades, except for Grade II gliomas where their sensitivities are comparable (95% and 90%). Very low specificity of MRI was observed in all grades of tumour (18-33%). In contrast the specificity of FDG PET-CT was high across all grades (83-100%). CONCLUSION: FDG PET-CT is a highly specific modality for detecting recurrence in patients with gliomas and can effectively exclude post therapy changes.

Long-term outcome of lobar ablation versus completion thyroidectomy in differentiated thyroid cancer.

BACKGROUND: Professional guidelines, both in Europe and North America, recommend completion thyroidectomy (CT) after lobe resection, except in very low-risk-differentiated thyroid cancer patients (tumor less than 1 cm; unifocal micropapillary carcinoma). Radioiodine lobar ablation (RAILA), which avoids complications associated with re-surgery, is an alternative that has been recently explored in a few international centers. However, this approach is being criticized as there are no published data available on its long-term outcomes with respect to recurrence rate, disease-free survival, and mortality compared with standard of care. This study was designed to compare the long-term outcome of RAILA with that of remnant ablation after CT. METHODS: Prospectively collected data were analyzed retrospectively from the case records of patients treated in our thyroid clinic in the last 25 years. The records of all patients of RAILA (364) and CT (372) were critically studied. Successful ablation rate, cumulative dose needed for complete ablation, recurrence rate, and recurrence-free survival were estimated for each group. Comparison between the two groups was made using the SPSS 11.5 statistical program. RESULTS: Radioiodine ablation rate at first dose of RAILA and remnant ablation after CT were 73 and 93.5%, respectively (P=0.03). However, after the second dose of I-131, the former group achieved successful ablation in 92% of patients. After a median follow-up period of 5 years (range 1-23 years), seven patients developed recurrence in the CT group (1.88%) and 14 in the RAILA group (3.8%); this was not statistically significant (P=0.168). The Kaplan-Meier disease-free survival curves between the two groups were statistically not significant (P=0.08). No cause-specific mortality in either group has been observed till date. CONCLUSION: Radioiodine lobar ablation is a safe, simple, effective, and less expensive alternative to CT in patients with differentiated thyroid cancer with comparable long-term outcome in terms of recurrence rate and disease-free survival.

Detection of recurrence in glioma: a comparative prospective study between Tc-99m GHA SPECT and F-18 FDG PET/CT.

BACKGROUND: Early and correct diagnosis of tumor recurrence and its differentiation from therapy-related changes is crucial for prompt and adequate management of glioma patients. The purpose of this study was to compare the efficacies of Tc-99m glucoheptonate (GHA) single photon emission tomography (SPECT) and F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in detection of recurrence in patients with glioma. METHODS: A total of 90 patients with histopathologically proven glioma who had suspicion of recurrence clinically or on magnetic resonance imaging were evaluated using Tc-99m GHA SPECT and FDG PET/CT. Combination of clinical follow-up, repeat imaging, and biopsy (when available) was taken as gold standard. RESULTS: On the basis of gold standard, 59 patients were positive and 31 were negative for tumor recurrence. The sensitivity, specificity, and accuracy of GHA SPECT were 85%, 97%, and 89%, respectively, whereas those of FDG PET/CT were 70%, 97%, and 80%, respectively. On subgroup analysis, GHA SPECT performed better than FDG PET/CT in all grades except for grade II gliomas, where both were equally effective. In all, 15 patients had intermodality discordance, with GHA SPECT being correct in 13 of them. CONCLUSIONS: GHA SPECT appears to be a better imaging modality than FDG PET/CT for detection of recurrent gliomas.

Comparison of glucoheptonate single photon emission computed tomography and contrast-enhanced MRI in detection of recurrent glioma.

BACKGROUND: Differentiation between recurrence and radiation necrosis in patients with glioma is crucial, as the two entities have completely different management and prognosis. The purpose of this study was to compare the efficacies of glucoheptonate (GHA) single photon emission computed tomography (SPECT) and contrast-enhanced MRI in the detection of recurrent glioma. METHODS: Eighty-five patients with histopathologically proven glioma with a clinical suspicion of recurrence were evaluated using Tc-99m GHA SPECT and MRI. A combination of clinical follow-up, repeat imaging and/or biopsy (when available) was taken as a gold standard. RESULTS: On the basis of the gold standard, 56 patients were positive and 29 were negative for tumour recurrence. The sensitivity, specificity and accuracy of GHA SPECT were 86.5, 96.5 and 89.4% respectively, whereas those of MRI were 94.6, 24.1 and 70.5% respectively. On subgroup analysis GHA SPECT had similar sensitivities with a much higher specificity than MRI across all grades. Thirty patients had intermodality discordance, with GHA SPECT being correct in 23 of them. CONCLUSION: GHA SPECT seems to be a highly sensitive and specific imaging modality for the detection of recurrent gliomas compared with contrast-enhanced MRI.

FDG PET-CT in the management of primary breast lymphoma.

OBJECTIVE: Primary breast lymphoma (PBL) is a rare disease and its management differs from other breast cancers. The purpose of this study is to evaluate the role of FDG PET-CT in the management of PBL. We carried out 16 PET-CT scans and reviewed the literature. MATERIALS AND METHODS: A total of 16 FDG PET-CT scans were done in 8 female patients with PBL with a median age of 49 years (range: 27-68). Of the 16 PET-CT scans, 1 scan was done for primary diagnosis and staging (1 patient), 2 for staging (2 patients), 7 for evaluation of treatment response (6 patients), and 6 for detecting recurrence (4 patients). PET-CT image interpretation and analysis were performed qualitatively (visually) and semiquantitatively using standardized uptake value (SUV). Absence of uptake in the postchemotherapy follow-up PET-CT scan was considered as a complete response, and a fall of more than 50% of baseline SUV was considered as a significant response. RESULTS: One patient was successfully diagnosed to have PBL and staged using PET-CT. Two patients were correctly staged with the help of FDG PET-CT. Complete response was noted in all 6 patients (3 had a positive baseline scan and showed complete resolution of FDG uptake, the other 3 who did not have baseline PET-CT and lesions were detected on CT, and also showed complete resolution). Of the 4 patients evaluated for recurrence, 1 patient was positive and 3 patients were negative for recurrence in follow-up PET-CT scans done after 18, 22, and 24 months, respectively. CONCLUSION: FDG PET-CT has a definitive role in every step of management (diagnosis, staging, treatment response evaluation, and detection of recurrence) in patients with primary breast lymphoma.