Sobhan Vinjamuri - Academia.edu (original) (raw)
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Papers by Sobhan Vinjamuri
European Journal of Nuclear Medicine and Molecular Imaging
Nuclear Medicine Communications
European Journal of Surgical Oncology
Purpose: To investigate the value of 18 FDG PET/CT volumetric parameters in the prediction of ove... more Purpose: To investigate the value of 18 FDG PET/CT volumetric parameters in the prediction of overall survival (OS) in patients with pancreatic cancer and also, assess their independence relative to well-established clinico-pathological variables. Methods: We conducted a retrospective analysis of patients with a confirmed diagnosis of pancreatic cancer who underwent 18 FDG PET/CT. The tumour maximum standardised uptake value (SUVmax) in addition to SUVmean, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were calculated. The prognostic value of 18 FDG PET/CT and clinico-pathological parameters for OS were assessed using univariate and multivariable analyses. Results: A sum of 89 patients were analysed in this study. Median survival for patients categorised as having high TLG (≥55) and low TLG (<55) was 18 vs 5 months (p < 0.001). Similarly, the respective high vs low SUVmean, MTV and SUVmax were 18 vs 6 months (p = 0.001), 16 vs 6 months (p = 0.002) and 18 vs 6 months (p = 0.001). Univariate analysis showed SUVmax, SUVmean, MTV, TLG, tumour size, tumour differentiation and presence of distant metastasis as prognostic factors for OS. On multivariable analysis, TLG (HR 2.0, 95% CI 1.26-3.18, p = 0.004) and the presence of distant metastasis (HR 3.37, 95% CI 1.97-5.77, p < 0.001) emerged as independent prognostic factors. Subgroup analysis identified TLG as the only significant PET metric after adjusting for the presence of distant metastasis. Conclusions: 18 FDG PET/CT is a useful tool in the preoperative evaluation of patients with pancreatic cancer. Tumour TLG offer an independent prognostic value in both potentially operable and metastatic disease settings.
Nuclear Medicine Communications
European Journal of Nuclear Medicine and Molecular Imaging
Diagnostics
Amyloid imaging using positron emission tomography (PET) has an emerging role in the management o... more Amyloid imaging using positron emission tomography (PET) has an emerging role in the management of Alzheimer’s disease (AD). The basis of this imaging is grounded on the fact that the hallmark of AD is the histological detection of beta amyloid plaques (Aβ) at post mortem autopsy. Currently, there are three FDA approved amyloid radiotracers used in clinical practice. This review aims to take the readers through the array of various indications for performing amyloid PET imaging in the management of AD, particularly using 18F-labelled radiopharmaceuticals. We elaborate on PET amyloid scan interpretation techniques, their limitations and potential improved specificity provided by interpretation done in tandem with genetic data such as apolipiprotein E (APO) 4 carrier status in sporadic cases and molecular information (e.g., cerebral spinal fluid (CSF) amyloid levels). We also describe the quantification methods such as the standard uptake value ratio (SUVr) method that utilizes variou...
Radiation Physics and Chemistry
Nuclear Medicine Communications
[
World journal of nuclear medicine
A 54-year-old female treated for locally advanced ductal breast carcinoma was also diagnosed with... more A 54-year-old female treated for locally advanced ductal breast carcinoma was also diagnosed with a pancreatic neuroendocrine tumour. A staging Ga DOTANOC positron emission tomography/computed tomography (PET/CT) demonstrated somatostatin receptor-positive foci within the brain parenchyma. A whole body F-fluoride PET/CT also demonstrated several foci of low-grade tracer uptake in the brain. Magnetic resonance imaging confirmed several cerebral and cerebellar metastases. This case highlights the need to be aware of each tumor's metastatic profile and the careful attention required for thoroughly evaluating imaging in the presence of multiple pathologies. Furthermore, such incidental findings can have significant treatment and prognostic implications.
Nuclear medicine communications, 2018
The objective of this study was to highlight the role of multimodality imaging and present the di... more The objective of this study was to highlight the role of multimodality imaging and present the differential diagnosis of abnormal tracer accumulation in the prostate and periprostatic tissue. Our departments have performed molecular imaging of the prostate utilizing PET-CT and PET-MRI with a range of biomarkers including F-FDG, radiolabelled choline, Ga-DOTATATE PET-CT and Ga-PSMA images. We retrospectively reviewed the varying appearances of the prostate gland in different diseases and incidental findings in periprostatic region. The differential diagnosis of pathologies related to prostate and periprostatic tissue on multimodality imaging includes malakoplakia, rhabdomyosarcoma, lymphoma, prostate cancer, neuroendocrine tumours, uchida changes, rectoprostatic fistula, synchronous malignancies, lymphocoele and schwanoma. There exists a wide differential for abnormal tracer accumulation in the prostate gland. As a radiologist and nuclear medicine physician, it is important to be awa...
Health technology assessment (Winchester, England), Feb 1, 2018
Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission... more Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer. To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer. A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy. Patients with suspected pancreatic malignancy. All patients to undergo PET/CT following standard diagnostic work-up. The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients' diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of pat...
World Journal of Nuclear Medicine
Nuclear Medicine Communications
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 18, 2017
Objective: This study sought to answer the calls for the restoration of reports of adverse reacti... more Objective: This study sought to answer the calls for the restoration of reports of adverse reactions from the European Association of Nuclear Medicine. It assessed reports of adverse reactions to radiopharmaceuticals (ARRPs) that were submitted to the British Nuclear Medicine Society's (BNMS) Radiopharmaceutical Adverse Reactions and Product Defects online database during the period January 2007 to December 2016. Methodology: This investigation was a pharmacovigilance based, non-experimental, cross-sectional study aimed at finding the prevalence and association between radiopharmaceuticals and adverse reactions. Results: During the period of the study, 204 reports were made of radiopharmaceutical adverse reactions, of which 13 were considered invalid. This was due primarily to incomplete entries, while in other cases the causality could not be determined. Tetrofosmin (34) and Oxidronate (32) had the highest prevalence, while Medronate accounted for 21 reports and both Sestamibi ...
Neuroendocrinology, Jan 12, 2017
The British Journal of Radiology, 2016
Clinical Nuclear Medicine, 2016
A 28-year-old woman with medullary thyroid cancer treated with total thyroidectomy and bilateral ... more A 28-year-old woman with medullary thyroid cancer treated with total thyroidectomy and bilateral central and right lateral neck nodal resection postoperatively had increasing calcitonin and carcinoembryonic antigen values. A Ga-DOTANOC PET/CT study performed showed tracer-avid disease in the neck, mediastinal, and hilar lymph nodes. However, there were 3 tracer-avid foci in the lungs bilaterally, suggestive of lung metastases but with no corresponding abnormalities on low-dose CT. A negative contrast-enhanced CT of the lungs along with clinical and radiological follow-up confirmed that the lung activity was artifactual, demonstrating the possibility of Ga-DOTANOC-avid iatrogenic pulmonary microembolism.
Journal of nuclear medicine technology, 2016
We describe the role of (18)F-sodium fluoride ((18)F-NaF) PET/CT bone scanning in the staging of ... more We describe the role of (18)F-sodium fluoride ((18)F-NaF) PET/CT bone scanning in the staging of breast and prostate cancer. (18)F-NaF PET was initially utilized as a bone scanning agent in the 1960s and early 1970s, however, its use was restricted by the then-available γ-cameras. The advent of hybrid PET/CT cameras in the late 1990s has shown a resurgence of interest in its use and role. After a brief introduction, this paper describes the radiopharmaceutical properties, dosimetry, pharmacokinetics, and mechanism of uptake of (18)F-NaF. The performance of (18)F-NaF PET/CT is then compared with that of conventional bone scintigraphy using current evidence from the literature. Strengths and weaknesses of (18)F-NaF PET/CT imaging are highlighted. Clinical examples of improved accuracy of diagnosis and impact on patient management are illustrated. Limitations of (18)F-NaF PET/CT imaging are outlined.
European Journal of Nuclear Medicine and Molecular Imaging
Nuclear Medicine Communications
European Journal of Surgical Oncology
Purpose: To investigate the value of 18 FDG PET/CT volumetric parameters in the prediction of ove... more Purpose: To investigate the value of 18 FDG PET/CT volumetric parameters in the prediction of overall survival (OS) in patients with pancreatic cancer and also, assess their independence relative to well-established clinico-pathological variables. Methods: We conducted a retrospective analysis of patients with a confirmed diagnosis of pancreatic cancer who underwent 18 FDG PET/CT. The tumour maximum standardised uptake value (SUVmax) in addition to SUVmean, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were calculated. The prognostic value of 18 FDG PET/CT and clinico-pathological parameters for OS were assessed using univariate and multivariable analyses. Results: A sum of 89 patients were analysed in this study. Median survival for patients categorised as having high TLG (≥55) and low TLG (<55) was 18 vs 5 months (p < 0.001). Similarly, the respective high vs low SUVmean, MTV and SUVmax were 18 vs 6 months (p = 0.001), 16 vs 6 months (p = 0.002) and 18 vs 6 months (p = 0.001). Univariate analysis showed SUVmax, SUVmean, MTV, TLG, tumour size, tumour differentiation and presence of distant metastasis as prognostic factors for OS. On multivariable analysis, TLG (HR 2.0, 95% CI 1.26-3.18, p = 0.004) and the presence of distant metastasis (HR 3.37, 95% CI 1.97-5.77, p < 0.001) emerged as independent prognostic factors. Subgroup analysis identified TLG as the only significant PET metric after adjusting for the presence of distant metastasis. Conclusions: 18 FDG PET/CT is a useful tool in the preoperative evaluation of patients with pancreatic cancer. Tumour TLG offer an independent prognostic value in both potentially operable and metastatic disease settings.
Nuclear Medicine Communications
European Journal of Nuclear Medicine and Molecular Imaging
Diagnostics
Amyloid imaging using positron emission tomography (PET) has an emerging role in the management o... more Amyloid imaging using positron emission tomography (PET) has an emerging role in the management of Alzheimer’s disease (AD). The basis of this imaging is grounded on the fact that the hallmark of AD is the histological detection of beta amyloid plaques (Aβ) at post mortem autopsy. Currently, there are three FDA approved amyloid radiotracers used in clinical practice. This review aims to take the readers through the array of various indications for performing amyloid PET imaging in the management of AD, particularly using 18F-labelled radiopharmaceuticals. We elaborate on PET amyloid scan interpretation techniques, their limitations and potential improved specificity provided by interpretation done in tandem with genetic data such as apolipiprotein E (APO) 4 carrier status in sporadic cases and molecular information (e.g., cerebral spinal fluid (CSF) amyloid levels). We also describe the quantification methods such as the standard uptake value ratio (SUVr) method that utilizes variou...
Radiation Physics and Chemistry
Nuclear Medicine Communications
[
World journal of nuclear medicine
A 54-year-old female treated for locally advanced ductal breast carcinoma was also diagnosed with... more A 54-year-old female treated for locally advanced ductal breast carcinoma was also diagnosed with a pancreatic neuroendocrine tumour. A staging Ga DOTANOC positron emission tomography/computed tomography (PET/CT) demonstrated somatostatin receptor-positive foci within the brain parenchyma. A whole body F-fluoride PET/CT also demonstrated several foci of low-grade tracer uptake in the brain. Magnetic resonance imaging confirmed several cerebral and cerebellar metastases. This case highlights the need to be aware of each tumor's metastatic profile and the careful attention required for thoroughly evaluating imaging in the presence of multiple pathologies. Furthermore, such incidental findings can have significant treatment and prognostic implications.
Nuclear medicine communications, 2018
The objective of this study was to highlight the role of multimodality imaging and present the di... more The objective of this study was to highlight the role of multimodality imaging and present the differential diagnosis of abnormal tracer accumulation in the prostate and periprostatic tissue. Our departments have performed molecular imaging of the prostate utilizing PET-CT and PET-MRI with a range of biomarkers including F-FDG, radiolabelled choline, Ga-DOTATATE PET-CT and Ga-PSMA images. We retrospectively reviewed the varying appearances of the prostate gland in different diseases and incidental findings in periprostatic region. The differential diagnosis of pathologies related to prostate and periprostatic tissue on multimodality imaging includes malakoplakia, rhabdomyosarcoma, lymphoma, prostate cancer, neuroendocrine tumours, uchida changes, rectoprostatic fistula, synchronous malignancies, lymphocoele and schwanoma. There exists a wide differential for abnormal tracer accumulation in the prostate gland. As a radiologist and nuclear medicine physician, it is important to be awa...
Health technology assessment (Winchester, England), Feb 1, 2018
Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission... more Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer. To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer. A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy. Patients with suspected pancreatic malignancy. All patients to undergo PET/CT following standard diagnostic work-up. The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients' diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of pat...
World Journal of Nuclear Medicine
Nuclear Medicine Communications
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 18, 2017
Objective: This study sought to answer the calls for the restoration of reports of adverse reacti... more Objective: This study sought to answer the calls for the restoration of reports of adverse reactions from the European Association of Nuclear Medicine. It assessed reports of adverse reactions to radiopharmaceuticals (ARRPs) that were submitted to the British Nuclear Medicine Society's (BNMS) Radiopharmaceutical Adverse Reactions and Product Defects online database during the period January 2007 to December 2016. Methodology: This investigation was a pharmacovigilance based, non-experimental, cross-sectional study aimed at finding the prevalence and association between radiopharmaceuticals and adverse reactions. Results: During the period of the study, 204 reports were made of radiopharmaceutical adverse reactions, of which 13 were considered invalid. This was due primarily to incomplete entries, while in other cases the causality could not be determined. Tetrofosmin (34) and Oxidronate (32) had the highest prevalence, while Medronate accounted for 21 reports and both Sestamibi ...
Neuroendocrinology, Jan 12, 2017
The British Journal of Radiology, 2016
Clinical Nuclear Medicine, 2016
A 28-year-old woman with medullary thyroid cancer treated with total thyroidectomy and bilateral ... more A 28-year-old woman with medullary thyroid cancer treated with total thyroidectomy and bilateral central and right lateral neck nodal resection postoperatively had increasing calcitonin and carcinoembryonic antigen values. A Ga-DOTANOC PET/CT study performed showed tracer-avid disease in the neck, mediastinal, and hilar lymph nodes. However, there were 3 tracer-avid foci in the lungs bilaterally, suggestive of lung metastases but with no corresponding abnormalities on low-dose CT. A negative contrast-enhanced CT of the lungs along with clinical and radiological follow-up confirmed that the lung activity was artifactual, demonstrating the possibility of Ga-DOTANOC-avid iatrogenic pulmonary microembolism.
Journal of nuclear medicine technology, 2016
We describe the role of (18)F-sodium fluoride ((18)F-NaF) PET/CT bone scanning in the staging of ... more We describe the role of (18)F-sodium fluoride ((18)F-NaF) PET/CT bone scanning in the staging of breast and prostate cancer. (18)F-NaF PET was initially utilized as a bone scanning agent in the 1960s and early 1970s, however, its use was restricted by the then-available γ-cameras. The advent of hybrid PET/CT cameras in the late 1990s has shown a resurgence of interest in its use and role. After a brief introduction, this paper describes the radiopharmaceutical properties, dosimetry, pharmacokinetics, and mechanism of uptake of (18)F-NaF. The performance of (18)F-NaF PET/CT is then compared with that of conventional bone scintigraphy using current evidence from the literature. Strengths and weaknesses of (18)F-NaF PET/CT imaging are highlighted. Clinical examples of improved accuracy of diagnosis and impact on patient management are illustrated. Limitations of (18)F-NaF PET/CT imaging are outlined.