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S Vinjamuri

Publications and source records attributed to S Vinjamuri.

At least 19 recordsLinked to original sources
PubMed2006

Genetic and metabolic predictors of chemosensitivity in oligodendroglial neoplasms.

The -1p/-19q genotype predicts chemosensitivity in oligodendroglial neoplasms, but some with intact 1p/19q also respond and not all with 1p/19q loss derive durable benefit from chemotherapy. We have evaluated the predictive and prognostic significance of pretherapy (201)Tl and (18)F-FDG SPECT and genotype in 38 primary and 10 recurrent oligodendroglial neoplasms following PCV chemotherapy. 1p/19q loss was seen in 8/15 OII, 6/15 OAII, 7/7 OIII, 3/11 OAIII and was associated with response (Fisher-Exact: P=0.000) and prolonged progression-free (log-rank: P=0.002) and overall survival (OS) (log-rank: P=0.0048). Response was unrelated to metabolism, with tumours with high or low metabolism showing response. Increased (18)F-FDG or (201)Tl uptake predicted shorter progression-free survival (PFS) in the series (log-rank: (201)Tl P=0.0097, (18)F-FDG P=0.0170) and in cases with or without the -1p/-19q genotype. Elevated metabolism was associated with shorter OS in cases with intact 1p/19q (log-rank: (18)F-FDG P=0.0077; (201)Tl P=0.0004) and shorter PFS in responders (log-rank: (18)F-FDG P=0.005; (201)Tl P=0.0132). (201)Tl uptake and 1p/19q loss were independent predictors of survival in multivariate analysis. In this initial study, (201)Tl and (18)F-FDG uptake did not predict response to PCV, but may be associated with poor survival following therapy irrespective of genotype. This may be clinically useful warranting further study.

Adult↗
PubMed2005

Positron emission tomography does not add to computed tomography for the diagnosis and staging of pancreatic cancer.

BACKGROUND: Positron emission tomography (PET) has been proposed for pancreatic cancer diagnosis and staging. METHODS: 112 patients with suspected pancreatic cancer underwent 18F-fluoro-2-deoxy-D-glucose gamma camera PET and computed tomography (CT), of whom 62 also had laparoscopic ultrasonography and 70 underwent abdominal exploration for potential resection. The final diagnosis was malignancy in 78 and benign disease in 34 patients (25 with chronic pancreatitis). RESULTS: The diagnostic sensitivity and specificity for PET were 73 and 60% compared to 89 and 65% for CT respectively (Cohen's kappa = 0.59). In 30 patients CT was equivocal with cancer in 14 and benign disease in 16. PET correctly diagnosed 13 of these patients (cancer in 6 and benign disease in 7), interpreted 4 as equivocal (cancer in 3 and benign disease in 1) but was incorrect in the remaining 13 patients (cancer in 5 and benign disease in 8). The sensitivity and specificity for detecting small volume metastatic disease were 20 and 94% for CT and 22 and 91% for PET, respectively. CONCLUSION: PET had a similar accuracy to that of CT for imaging pancreatic cancer but it did not provide any additional information in patients with equivocal CT findings and currently would seem of little benefit for the staging of pancreatic cancer.

Adult↗
PubMed2005

Single-photon emission computed tomography perfusion imaging in the differential diagnosis of dementia: a retrospective regional audit.

A retrospective audit of (99m)Tc-HMPAO SPECT scans was undertaken to assess the utility of brain perfusion imaging in a cohort of young cognitively impaired patients in whom diagnostic uncertainty remained after standard clinical and neuropsychological assessment and structural brain imaging. SPECT scans were assessed by five raters (two neurologists and three nuclear medicine specialists) on two occasions 6 months apart, first without any clinical data and second with brief pertinent clinical information. SPECT diagnoses were compared with criterion diagnoses subsequently established by the two neurologists with access to all clinical, neuropsychological and neuroimaging data. Despite reasonable intra- and interrater reliability, diagnostic accuracy ranged from 32 to 58%. SPECT scan normality or abnormality in blind and informed viewings gave respective sensitivities of 77 and 71%, specificities of 44 and 38%, positive predictive values of 88 and 87% and negative predictive values of 27 and 18%. Calculating pairwise disease group comparisons, likelihood ratios suggested some diagnostic gain in differentiating AD from 'not AD' and from FTD/focal syndromes. SPECT scanning was of little help in establishing diagnoses in this cohort of patients, a finding which supports the conclusion of the American Academy of Neurology evidence-based review that SPECT imaging cannot be recommended for either the initial or the differential diagnosis of suspected dementia because it has not demonstrated superiority to clinical criteria.

Adult↗
PubMed2004

Hereditary pancreatic endocrine tumours.

The two main types of hereditary pancreatic neuroendocrine tumours are found in multiple endocrine neoplasia type 1 (MEN-1) and von Hippel-Lindau disease (VHL), but also in the rarer disorders of neurofibromatosis type 1 and tuberous sclerosis. This review considers the major advances that have been made in genetic diagnosis, tumour localization, medical and surgical treatment and palliation with systemic chemotherapy and radionuclides. With the exception of the insulinoma syndrome, all of the various hormone excess syndromes of MEN-1 can be treated medically. The role of surgery however remains controversial ranging from no intervention (except enucleation for insulinoma), intervening for tumours diagnosed only by biochemical criteria, intervening in those tumours only detected radiologically (1-2 cm in diameter) or intervening only if the tumour diameter is > 3 cm in diameter. The extent of surgery is also controversial, although radical lymphadenectomy is generally recommended. Pancreatic tumours associated with VHL are usually non-functioning and tumours of at least 2 cm in diameter should be resected. Practice guidelines recommend that screening in patients with MEN-1 should commence at the age of 5 years for insulinoma and at the age of 20 years for other pancreatic neuroendocrine tumours and variously at 10-20 years of age for pancreatic tumours in patients with VHL. The evidence is increasing that the life span of patients may be significantly improved with surgical intervention, mandating the widespread use of tumour surveillance and multidisciplinary team management.

Endocrine Gland Neoplasms↗
PubMed2003

Does diastolic function evaluated with radionuclide ventriculography predict mortality, hospitalization and the development of new onset heart failure?

Left ventricular systolic dysfunction (LVSD) in asymptomatic patients is associated with the development of heart failure (HF) and the degree of LVSD predicts prognosis. Whether left ventricular diastolic dysfunction (LVDD) predicts the development of HF or mortality is not known. Our objective was to investigate the predictive value of LVDD evaluated by radionuclide ventriculography (RN). All patients referred for RN during a 12 month period were included. Medical records were reviewed to determine characteristics of the patients at the time of RN and events occurring during a 5 year follow-up. Data from 195 patients were analysed. During the follow-up period 49 patients (25.1%) died, 41 (21.0%) were admitted to hospital and 25 (12.3%) developed HF. An ejection fraction (EF) <40% was associated with mortality (relative risk (RR), 2.04; P=0.001) and hospital admissions (RR, 1.33; P=0.002). Patients who developed subsequent HF had, on average, lower EF at baseline. In a multivariate analysis the lower the EF the more likely patients were to develop new onset HF (odds ratio, 0.92; 95% CI 0.88-0.97; P=0.003). LVDD evaluated with peak filling rate and time to peak filling rate was not associated with any of the outcomes. However, a higher proportion of patients with pre-existing HF at the time of the RN had abnormal LVDD than patients with no HF. LVDD evaluated by RN is associated with symptoms of HF at the time of assessment but is not a good predictor of mortality, hospitalization or new onset HF. EF remains a better predictor of outcomes.

Adolescent↗
PubMed2003

Surgery for midgut carcinoid.

Many clinicians prefer to avoid surgery in patients with carcinoid neoplasia, because of its slow growth and relatively favourable prognosis. Nevertheless, the commonest cause of death in patients with carcinoid is advanced metastatic disease, and both clinical and epidemiological data indicate that the more effectively the disease is ablated, the more long-lasting the benefit. Multidisciplinary management of patients with carcinoid must consider inherited risk, possible multiple carcinoids and/or synchronous non-carcinoid cancer, and the use of a range of investigations that also evaluate the 10% of patients with carcinoid syndrome with or without valvular heart disease. Although primary size is correlated with the presence of nodal with or without liver metastases, carcinoid tumours <1 cm in diameter may be metastatic at presentation, particularly those arising within the small intestine. In the jejunum and ileum, resection of all sizes of carcinoid with local and regional nodes is preferred, to prevent nodal dissemination causing mesenteric ischaemia with or without infarction. Resection of nodal metastases should be undertaken in those with persistent or recurrent nodal disease if possible. Appendiceal and right colonic carcinoids are most effectively treated by right hemicolectomy with local and regional nodal clearance, as for adenocarcinoma. However, for most appendiceal carcinoids which are <1 cm in diameter and non-invasive, appendicectomy alone is sufficient. For appendiceal carcinoids 1-2 cm in diameter, histopathological assessment helps to determine the need for hemicolectomy. Liver resection has been followed by prolonged 5 year survival in several series and is recommended in appropriate patients to attempt cure or to debulk metastatic disease. Liver transplantation has had only qualified success in highly selected patients without extra-hepatic disease in whom other therapies have failed.

Carcinoid Tumor↗
PubMed2001

(131)I-MIBG radionuclide therapy is safe and cost-effective in the control of symptoms of the carcinoid syndrome.

BACKGROUND: The standard treatment used to control the symptoms of carcinoid syndrome (CS) involves subcutaneous injections of the somatostatin analogue octreotide. This is expensive (US $8000--16,000 per year), and treatment may be for many years. The aim of this study was to evaluate the efficacy and cost-effectiveness of our experience over the last 5 years with 1-131-labelled metaiodobenzylguanidine (MIBG) radionuclide therapy in the palliation of patients with CS. METHODS: A consecutive series of 20 symptomatic patients (referred between 1994 and 1999) with CS were evaluated. Fifteen of them underwent(123)I-MIBG scanning. Of the 13 patients with significant tracer uptake in metastatic deposits compared to background, 12 underwent a course of therapeutic(131)I-MIBG (one patient refused). Symptoms, biochemical markers, CT scans, follow-up(123)I-MIBG scans, and the requirement for octreotide were used to assess outcome of treatment. Costs of(131)I-MIBG and octreotide treatments were compared. RESULTS: MIBG treatment was well tolerated in all with only transient side-effects. Ten patients showed a measurable clinical improvement. Seven had a complete clinical response. The mean duration of response was 15.4 months. Octreotide was not required or was reduced in eight patients. Treatment with(131)I-MIBG resulted in a saving of US $1000 per patient, with effective symptom control, when compared to octreotide. CONCLUSION: 1-131 MIBG therapy is a safe and cost-effective therapeutic option to successfully control symptoms in patients with carcinoid syndrome.

3-Iodobenzylguanidine↗
PubMed2001

The radiographer and role expansion in nuclear medicine.

With the introduction and wide application of Clinical Governance to all clinical areas, all healthcare professionals including radiographers/technologists working in Nuclear Medicine need to gain skills required for implementation. New professional and legal obligations demand that relevant expertise is developed. This article examines the potential for role expansion of radiographers/technologists in Nuclear Medicine with emphasis on the training and development aspects. The key areas addressed include clinical audit, risk management, research, management and continuing professional development.

Allied Health Personnel↗
PubMed2000

Significance of white matter abnormalities in patients with closed head injury.

Neuroimaging in patients with closed head injury (CHI) may frequently reveal abnormalities of white matter. Because white matter abnormalities may be seen in patients aged over 40 years even without CHI, the significance of these abnormalities in patients with CHI is questionable and needs to be assessed in the context of relevance to clinical outcome. The aims of this study were to determine the relative incidence of white matter abnormalities in a group of patients with CHI, and to assess the impact (if any) of these abnormalities on clinical outcome. Sixty-three patients with CHI underwent neuroimaging with magnetic resonance imaging (MRI) and regional cerebral blood flow (rCBF) single photon emission tomography (SPET) approximately 6 months after trauma. Seven patients had white matter abnormalities on MRI scanning. There are no rCBF SPET criteria for defining abnormal perfusion to the white matter. The SPET scans ranged from normal (one patient) and abnormal perfusion to frontal, temporal or parietal lobes in these patients (n = 6). Patients were assessed for outcome after undergoing appropriate rehabilitation programmes with indices of reintegration into the community, activities of daily living, disability, and their cognitive ability to perform tasks. This assessment was conducted 2 years after initial trauma. Of these seven patients with abnormal MRI of the white matter, one performed poorly and six had moderate to good clinical outcome. When individual lobar perfusion is considered, abnormal perfusion to the frontal or temporal lobes was significantly associated with poorer outcome (P < 0.005). In conclusion, white matter abnormalities detected by MRI are frequently associated with cortical perfusion defects identified by SPET (6/7 or 86%). However, when these white matter abnormalities were accompanied by perfusion defects in the frontal and temporal lobes, these were statistically significant in predicting poorer outcome.

Activities of Daily Living↗
PubMed2000

Serial perfusion brain tomographic scans detect reversible focal ischaemia in Rasmussen's encephalitis.

A 39-year-old man with advanced adult-onset Rasmussen's encephalitis was treated with prednisolone and long-term, high-dose, human intravenous immunoglobulin. A pretreatment, semiquantitative interictal brain perfusion single photon emission computed tomography (SPECT) scan using (99)Tc(m) HMPAO (hexamethylene propylene amine oxime) showed hypoperfusion in the clinically affected right frontal, parietal and temporal lobes and contralateral perfusion defects. A second scan 8 months later revealed significant improvements (more than two standard deviations) in perfusion of the right frontal and temporal lobes despite serial magnetic resonance imaging evidence of permanent brain damage. This was associated with useful recovery of the patient's physical and cognitive function. We conclude that serial perfusion brain SPECT scanning is a useful method to demonstrate improvement in patients with Rasmussen's encephalitis in response to therapy.

Adult↗
PubMed1998

Gastroesophageal reflux in patients fed by percutaneous endoscopic gastrostomy (PEG): detection by a simple scintigraphic method.

OBJECTIVES: Gastroesophageal scintigraphy has been described as a sensitive and accurate way to detect and quantitate gastroesophageal reflux (GER). Our objectives here were to evaluate the usefulness of a modified scintigraphic technique in the detection of GER and lung aspiration in patients fed by percutaneous endoscopic gastrostomy (PEG), and to assess the incidence of GER after insertion of PEG. Further, we sought to examine whether or not the underlying cause of dysphagia plays any significant part in the causation of GER. METHODS: Twenty-two patients, 13 with neurological dysphagia and nine with mechanical dysphagia, were studied. Each patient received 25 MBq of Tc-99m-tin colloid in orange juice followed by 300 ml of normal saline through the PEG tube. Dynamic and static images were taken immediately and at 4 h over esophagus, stomach, and lungs. RESULTS: Twelve patients (10 with neurological dysphagia) had GER and one had aspiration into the lungs. In all but one patient GER occurred in the immediate postprandial period. CONCLUSIONS: Scintigraphy is useful in assessing GER in PEG-fed patients. We also note that GER is a major problem in patients with PEG, especially in those with neurological dysphagia.

Adult↗
PubMed1998

Evaluation of the efficacy of 99mTc-Infecton, a novel agent for detecting sites of infection.

AIMS: To determine the sensitivity and specificity of 99mTc-Infecton (Infecton), a novel ciprofloxacin based imaging agent, in detecting sites of infection. METHODS: Ninety patients thought to be suffering from a variety of infections were administered 300-400 MBq of Infecton intravenously. Whole body images were taken one and four hours later. Appropriate specimens were taken for microbiological investigations. Statistical analysis was performed using a computer statistical package. RESULTS: Ninety eight Infecton images were produced. Forty one of these were positive, including three false positives, where the patients had non-infective conditions. Fifty seven negative images were obtained, of which 41 were true negatives and 16 were false negatives, having definite evidence of infection. Thus, Infecton imaging has a sensitivity of 70.3% and a specificity of 93.1% for detecting infective foci. The positive and negative predictive values were 92.6% and 71.9%, respectively. CONCLUSION: Infecton imaging is a new diagnostic tool that is specific for detecting sites of bacterial infection in the body. The high positive predictive value displayed by the technique is clinically important because a positive image strongly supports a diagnosis of bacterial infection. A negative result does not rule out an infection, and may be a result of previous or current antibiotic treatment and/or infection with organisms that do not take up Infecton. Infecton imaging has major advantages over well established imaging techniques, including radiolabelled leucocytes, and may prove to be a superior method for localising bacterial infections.

Adolescent↗