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ABSTRACT: BACKGROUND: We studied the distribution and expression of translocator protein in the human brain using 11C-[R]-PK-11195 positron emission tomography (PK11195 PET) and evaluated age-related changes. METHODS: A dynamic PK11195 PET scan was performed in 15 normal healthy adults (mean age: 29 +/-8.5 years (range: 20 to 49); 7 males) and 10 children (mean age: 8.8 +/-5.2 years (range: 1.2 to 17); 5 males), who were studied for potential neuroinflammation but showed no focally increased PK11195 binding. The PET images were evaluated by calculating standard uptake values and regional binding potential, based on a simplified reference region model, as well as with a voxel-wise analysis using statistical parametric mapping. RESULTS: PK11195 uptake in the brain is relatively low, compared with the subcortical structures, and symmetrical. The overall pattern of PK11195 distribution in the brain does not change with age. PK11195 uptake was lowest in the frontal-parietal-temporal cortex and highest in the pituitary gland, midbrain, thalamus, basal ganglia, occipital cortex, hippocampus and cerebellum, in descending order. White matter showed negligible PK11195 uptake. Overall, brain PK11195 uptake increased with age, with midbrain and thalamus showing relatively higher increases with age compared with other brain regions. CONCLUSIONS: The brain shows low PK11195 uptake, which is lower in the cortex and cerebellum compared with subcortical structures, suggesting a low level of translocator protein expression. There is no hemispheric asymmetry in PK11195 uptake and the overall pattern of PK11195 distribution in the brain does not change with age. However, brain PK11195 uptake increases with age, with the thalamus and midbrain showing relatively higher increases compared with other brain regions. This increase in uptake suggests an age-related increase in translocator protein expression or the number of cells expressing these receptors or both.
Journal of Neuroinflammation 10/2012; 9(1):232. · 3.83 Impact Factor
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ABSTRACT: Inflammatory enthesitis is a hallmark of spondyloarthropathies (SSA) and may antedate other clinical manifestations. The involvement of Achilles tendon and plantar aponeurosis is common, with strong tendency toward fibrosis and calcification. We are describing imaging characteristics in a patient with positive HLA B-27 antigen with bilateral calcific achilles tendonitis who had pain in heels for 3 years.
Clinical nuclear medicine 02/2012; 37(2):172-4. · 3.92 Impact Factor
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ABSTRACT: The objective of this study is to determine the long-term outcome of children with intractable epilepsy who have diffuse cortical hypometabolism on 2-deoxy-2-((18)F)fluoro-D-glucose positron emission tomography (FDG-PET) scans. Seventeen children with intractable epilepsy showing bilateral, diffuse cortical hypometabolism on FDG-PET were followed up through telephone interview from 1 year 4 months to 11 years 4 months (mean: 5 years 7 months ± 2 years 1 month) after their PET scans. One child succumbed to Sanfilippo disease at age 20 years. Only 2 children were seizure free. Fifty percent had walking difficulties, 56.25% were not toilet trained, all had speech difficulties, 43.75% had behavioral problems, 37.5% had poor eye contact, 75% had socialization difficulties, and 87.5% attended special schools. Three children were found to have genetic causes, including a 4-MB deletion of the mitochondrial genome, MECP2 duplication, and Lafora disease. In conclusion, the long-term outcome in this patient population is poor, and they tend to suffer from genetic/neurodegenerative diseases.
Journal of child neurology 09/2011; 27(1):39-45. · 1.59 Impact Factor
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ABSTRACT: Adrenal metastasis in renal cell carcinoma (RCC) is uncommon. The present study was aimed to evaluate the role of fluoro-deoxy-glucose positron emission tomography (FDG PET)/computed tomography (CT) in the detection of adrenal metastasis in patients with RCC.
A total of 9 FDG PET/CT scans were performed in 4 patients (3 males, 1 female; median age: 53.5 years, range: 52-73 years). Of 9 PET/CT scans, 2 scans were done for initial staging, 2 for restaging, and 5 for evaluation of treatment response. PET/CT image interpretation and analysis was performed qualitatively (visually) and semiquantitatively. Absence of uptake in postchemotherapy PET/CT scan was considered as complete response and a fall in SUV by more than 50% of baseline value, as significant response.
Patients 1 and 2 underwent staging FDG PET/CT. Patient 1 had undergone left radical nephrectomy 13 years back for left-sided RCC. Current FDG PET/CT revealed appearance of right RCC with adrenal metastasis. PET/CT of patient 2 demonstrated right adrenal and distant metastases. PET/CT done for restaging in patient 3, revealed right adrenal and abdominal lymph nodal metastasis. In patient 4, PET/CT revealed solitary adrenal metastasis. Magnetic resonance imaging findings were consistent with adrenal metastasis in this patient. Patient 1 received sunitinib and interferon chemotherapy along with radiotherapy and showed partial response on PET/CT scans done at 6, 17, 23, and 33 months from the initial study. PET/CT of patient 3 demonstrated the progression of disease (nonresponder).
FDG PET/CT appears to be useful for staging, treatment response evaluation, and recurrence detection in patients with RCC having adrenal metastasis.
Clinical nuclear medicine 07/2011; 36(7):513-7. · 3.92 Impact Factor
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ABSTRACT: This study was performed to evaluate the cerebral protein synthesis rate of language brain regions in children with developmental delay with and without pervasive developmental disorder. The authors performed L-[1-(11)C]-leucine positron emission tomography (PET) on 8 developmental delay children with pervasive developmental disorder (mean age, 76.25 months) and 8 developmental delay children without pervasive developmental disorder (mean age, 77.63 months). They found a higher protein synthesis rate in developmental delay children with pervasive developmental disorder in the left posterior middle temporal region (P = .014). There was a significant correlation of the Gilliam Autism Rating Scale autism index score with the protein synthesis rate of the left posterior middle temporal region (r = .496, P = .05). In addition, significant asymmetric protein synthesis (right > left) was observed in developmental delay children without pervasive developmental disorder in the middle frontal and posterior middle temporal regions (P = .03 and P = .04, respectively). In conclusion, abnormal language area protein synthesis in developmentally delayed children may be related to pervasive symptoms.
Journal of child neurology 06/2011; 26(11):1347-54. · 1.59 Impact Factor
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ABSTRACT: to evaluate the treatment response in patients with recurrent colorectal cancer (CRC) using FDG PET/CT.
a total of 32 recurrent CRC patients (21 males, 11 females; mean age, 52.8 years) were included in this retrospective study. All patients underwent a baseline and follow-up FDG PET/CT scans after chemotherapy. Of 32 patients, 23 patients had follow-up carcinoembryonic antigen (CEA) levels.
on qualitative analysis of baseline and follow-up FDG PET/CT studies, there were 20 nonresponders and 12 were responders. On quantitative analysis, there were 19 nonresponders and 13 were responders. In responders, baseline and follow-up mean SUV(max) were 11.8 ± 10.1 and 3.7 ± 4.1, respectively (significant decrease, P = 0.001). Among nonresponders, baseline and follow-up mean SUV(max) were 8.1 ± 5.2 and 14.1 ± 9.0, respectively (significant increase, P = 0.003). There was no association between response and different factors like age, sex, diagnosis, extent of the lesions, and number of lesions.
FDG PET/CT appears to be useful modality in evaluating chemotherapy response and can differentiate responders from nonresponders in recurrent CRC patients.
Clinical nuclear medicine 01/2011; 36(1):11-6. · 3.92 Impact Factor
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ABSTRACT: To determine the efficacy of positron emission tomography-computed tomography using F-18 fluoro-deoxy-glucose (F-18 FDG PET-CT) in diagnosing the recurrence of renal cell carcinoma (RCC) in patients treated earlier with partial or radical nephrectomy.
We assessed 63 patients with suspected recurrent RCC after nephrectomy. PET-CT findings were interpreted as positive if the focal area of FDG uptake in the abdomen or outside the abdomen was more than the surrounding background tissue. The final diagnosis of the recurrence of RCC was based on histological examination and/or clinical follow-up and conventional imaging modalities.
A total of 103 PET-CT studies were done in these 63 patients, of which 63 studies were true positive, 30 studies were true negative, seven studies were false negative and remaining three studies were false positive. In 63 true-positive scans, PET-CT showed 109 lesions. Of these, 28 lesions were in the lungs, 21 lesions were at a locoregional site, 21 were in the bones, 12 in the retroperitoneal lymph nodes and 27 at other sites. The sensitivity, specificity and accuracy of PET-CT were 90, 91 and 90%, respectively.
Our results seem to confirm the useful role of PET-CT in the evaluation of post-surgical recurrence in patients who had undergone radical surgery for RCC.
Nuclear Medicine Communications 10/2010; 31(10):844-50. · 1.40 Impact Factor
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Shamim Ahmed Shamim,
Rakesh Kumar,
Dhanapathi Halanaik,
Ashok Kumar, Varun Shandal,
Jaya Shukla,
Ajay Kumar,
Vivek Trikha,
Prem Chandra,
Gurupad Bandopadhayaya,
Arun Malhotra
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ABSTRACT: To evaluate the treatment response of rhenium-188 (¹⁸⁸Re) tin colloid radiosynovectomy (¹⁸⁸Re-RSV) in patients with inflammatory knee joint conditions refractory to conventional treatment.
Sixty-one knee joints in 48 patients with chronic synovitis caused by various inflammatory knee joint diseases refractory to conventional therapy were included in this prospective study. All patients were assessed clinically for pain, tenderness, joint swelling, mobility, analgesic intake, and blood pool activity on bone scan. Different scores were assigned to all these parameters. RSV of knee joint was done using intra-articular injection of 555 MBq of ¹⁸⁸Re tin colloid. Response was assessed at 3, 6, and 12 months using various clinical parameter scores and blood pool bone scan mentioned above and categorized as responders and nonresponders on the basis of change in percentage of cumulative scores.
Of the 61 joints, 57 were responder and four were nonresponder at 3-month post-RSV. Out of 57 responders, seven had recurrence on further follow-up (three at 6 months and four at 12 months). There was a statistically significant reduction in clinical parameters cumulative scores at 3, 6, and 12 months when compared with baseline (P<0.0001) in responder group. Blood pool scinitgraphy also showed decrease in blood pool activity compared with the baseline. There was statistically significant association between the responder group and shorter duration of disease (P=0.011). Patients having normal or minor X-ray changes, little or no swelling, mild tenderness, and better mobility were independently associated with good response.
¹⁸⁸Re tin colloid synovectomy is a useful treatment modality in patients with chronic inflammatory knee joint conditions refractory to conventional treatment. Patients with shorter duration of disease, normal or minor X-ray findings, little or no swelling, mild tenderness, and better mobility are better candidates for RSV.
Nuclear Medicine Communications 09/2010; 31(9):814-20. · 1.40 Impact Factor
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BJU International 07/2010; 106(1):132-3. · 2.84 Impact Factor
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ABSTRACT: The common childhood cancers are leukemia, CNS tumors, lymphomas, soft-tissue tumors (such as rhabdomyosarcoma and fibrosarcoma), neuroblastoma, malignant bone tumors, germ cell tumors with neoplasms of gonads and hepatic tumors. Usually the conventional imaging modalities, such as x-ray, ultrasound, computed tomography (CT) and MRI, are being routinely used for the management of these pediatric malignancies. However, most of these modalities provide structural information and are lacking in functional/metabolic status of these malignancies. Recently, PET and PET/CT have emerged as a functional diagnostic imaging modality for the management of various cancers in adult population. Up to now most of the data published in the literature are on PET alone. PET used in conjunction with CT is useful as it provides an enhanced view of the anatomical details and the malignant focus then can be located with highest accuracy. PET and PET/CT has been found to be useful in, for example, CNS tumors, lymphomas, soft-tissue tumors, neuroblastoma, malignant bone tumors and germ cell tumors. PET/CT has a limited role in early diagnosis, however, it plays an important role in initial staging, treatment response evaluation and detection of metastatic disease in these cancers. Despite the fact that PET/CT has better diagnostic value when compared with conventional imaging, such as CT and MRI, in the management of many pediatric cancers, there are certain limitations. PET/CT has a limited role in detection of lesions smaller than 5 mm, well-differentiated tumors and tumors with low metabolic rate. Many infections and inflammation can lead to false-positive PET/CT results. In the present review we will discuss the various clinical indications of PET and PET/CT in pediatric cancers.
Expert Review of Anti-infective Therapy 05/2010; 10(5):755-68. · 2.65 Impact Factor
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ABSTRACT: One-third of patients with colorectal cancer (CRC) are likely to have a recurrence within the first 1-2 years. Conventional imaging modalities have limitations in detecting recurrent disease early. The purpose of this study was to assess the usefulness of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in the detection of recurrence in patients with CRCs.
One hundred and eighty-three patients, who were earlier treated with surgery and/or chemotherapy/radiotherapy, underwent 269 PET/CT studies for the detection of recurrence. The final diagnosis was made on the basis of histological analysis or clinical and imaging follow-up.
The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value in detecting recurrent CRC using F-FDG-PET/CT were 87, 90, 88, 93, and 80%, respectively. PET/CT was found to have limitations in detecting microscopic disease and small-sized lesions. The common cause of false-positive PET/CT results was infective and inflammatory pathology in our setup.
PET/CT showed high sensitivity, specificity, and accuracy for the detection of recurrent disease in patients, who were earlier treated for CRC. PET/CT can be considered as a useful diagnostic tool in these patients.
Nuclear Medicine Communications 03/2010; 31(6):590-6. · 1.40 Impact Factor
