Biomedical subjects

Robert E Ware

Publications and source records attributed to Robert E Ware.

9 recordsLinked to original sources

PubMed2007

How do oncologists deal with incidental abnormalities on whole-body fluorine-18 fluorodeoxyglucose PET/CT?

BACKGROUND: Combined positron emission tomography (PET)/computed tomography (CT) using fluorine-18 fluorodeoxyglucose (FDG) is an exciting technique for cancer evaluation, but false-positive results are a recognized limitation. The aim of the study was to evaluate how oncologists deal with focal extrathyroidal FDG abnormalities considered by imaging specialists to be unrelated to the referral indication. METHODS: PET scan reports from a 12-month period from August 2002 to July 2003 in 1727 consecutive patients (mean age, 63 years) were reviewed. Incidental, nonphysiologic FDG abnormalities were classified based on the report conclusion. The frequency with which such abnormalities were investigated by oncologists and the final diagnosis were compared with the imaging diagnosis with a minimum potential follow-up of 2 years (mean, 27.5 months). RESULTS: Incidental FDG abnormalities were reported in 199 (12%) of 1727 patients, including 181 with adequate follow-up. Of 59 cases with a suspected second malignancy, 34 (58%) were actively investigated, with 14 confirmed, 7 unexpected metastatic sites, and 10 other active pathologies. Only 1 further cancer was subsequently detected in the 25 (42%) patients not actively investigated. Conversely, of 122 sites presumed to be benign, only 10 (8%) were actively investigated. Only 2 were proven to relate to malignancy. CONCLUSIONS: Although incidental abnormalities were common, most were benign and appropriately categorized by experienced readers. For actively investigated extrathyroidal abnormalities, a neoplastic basis was confirmed in over 60% of cases. Conversely, for cases deemed most likely benign by the PET/CT report or after review of readily available clinical information by the referring oncologist, the rate of malignancy was less than 2%.

Adult↗

PubMed2006

PET/CT: will it change the way that we use CT in cancer imaging?

Accurate staging of cancer is of fundamental importance to treatment selection and planning. Current staging paradigms focus, first, on a detailed delineation of the primary tumour in order to determine its suitability for resection, and, thereafter, on assessment of the presence of metastatic spread that would alter the surgical approach, or mandate non-surgical therapies. This approach has, at its core, the assumption that the best, and sometimes the only, way to cure a patient of cancer is by surgical resection. Unfortunately, all non-invasive techniques in current use have imperfect ability to identify those primary tumours that are able to be completely excised, and even worse ability to define the extent of metastatic spread. Nevertheless, because of relatively low cost and widespread availability, computed tomography (CT) scanning is the preferred methodology for tumour, nodal and systemic metastasis (TNM) staging. This is often supplemented by other tests that have improved performance in particular staging domains. For example, magnetic resonance imaging (MRI), mammography, or endoscopic ultrasound may be used as complementary tests for T-staging; surgical nodal sampling for N-staging; and bone scanning, MRI or ultrasound for M-staging. Accordingly, many patients undergo a battery of investigations but, even then, are found to have been incorrectly staged based on subsequent outcomes. Even for those staged surgically, pathology can only identify metastases within the resection specimens and has no capability for detecting remote disease. As a result of this, many patients undergo futile operations for disease that could never have been cured by surgery. In the case of restaging, the situation is even worse. The sequelae of prior treatment can be difficult to differentiate from residual cancer and the likelihood of successful salvage therapy is even less than at presentation. More deleteriously, patients may be subjected to additional morbid treatments when cure has already been achieved. Thus, in post-treatment follow-up, the presence and extent of disease is equally critical to treatment selection and patient outcome as it is in primary staging. One of the major strengths of positron emission tomography (PET)/CT as a cancer staging modality is its ability to identify systemic metastases. At any phase of cancer evaluation, demonstration of systemic metastasis has profound therapeutic and prognostic implications. Only in the absence of systemic metastasis does nodal status become important, and only when unresectable nodal metastasis has been excluded does T-stage become important. There are now accumulating data that PET/CT could be used as the first, rather than the last test to assess M- and N-stage for evaluating cancers with an intermediate to high pre-test likelihood of metastatic disease based on poor long-term survival. In this scenario, there is great opportunity for subsequently selecting and tailoring the performance of anatomically based imaging modalities to define the structural relations of abnormalities identified by PET, when this information would be of relevance to management planning. Primary staging of oesophageal cancer and restaging of colorectal cancer are illustrative examples of a new paradigm for cancer imaging.

Adenocarcinoma↗

PubMed2006

Powerful prognostic stratification by [18F]fluorodeoxyglucose positron emission tomography in patients with metastatic breast cancer treated with high-dose chemotherapy.

PURPOSE: This study examines the use of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) for the evaluation of the therapeutic response for patients treated with high-dose chemotherapy (HDC) with autologous stem cell transplantation for metastatic breast cancer (MBC) focusing on prognostic stratification. PATIENTS AND METHODS: Forty-seven patients with MBC were treated with a maximum of three cycles of HDC. Therapeutic response was assessed with conventional imaging (CImg; including a computed tomography in all cases and ultrasound, mammography, and bone scanning as clinically indicated) and by FDG-PET study performed after the last cycle of HDC. Parameters analyzed for predicting survival were FDG-PET and CImg results, pattern of disease, prior treatment, and HDC regimen. RESULTS: Complete responses were observed in 16 patients (37%) with CImg and 34 patients (72%) with FDG-PET. The FDG-PET result was the most powerful and independent predictor of survival; patients with a negative post-treatment FDG-PET had a longer median survival than patients with a positive FDG-PET (24 months v 10 months; P < .001). By multivariate analysis the relative risk (RR) of death was higher in patients with FDG-PET-positive disease (RR, 5.3), prior anthracycline treatment (RR, 3.3), or with visceral metastasis (RR, 2.4). CONCLUSION: A single FDG-PET study performed after completion of HDC for MBC can powerfully stratify for survival. This may have implications for how we should assess outcome after conventional-dose therapy for MBC and warrants additional study.

Adult↗

PubMed2005

Clinical experience with the first combined positron emission tomography/computed tomography scanner in Australia.

Metabolic imaging with fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) is increasing rapidly worldwide because of superior accuracy compared with conventional non-invasive techniques used for evaluating cancer. Limited anatomical information from FDG-PET images alone dictates that complementary use with structural imaging is required to optimise benefit. Recently, combined positron emission tomography/computed tomography (PET/CT) scanners have overtaken standalone PET scanners as the most commonly purchased PET devices. We describe our experience of over 5500 scans performed since the first PET/CT scanner in Australia was commissioned at the Peter MacCallum Cancer Centre (PMCC), Melbourne, in January 2002. Clinical indications for PET/CT scans performed at PMCC largely reflect current Medicare reimbursement policy. Advantages of PET/CT include greater patient comfort and higher throughput, greater diagnostic certainty and accuracy, improved biopsy methods, and better treatment planning. We believe PET/CT will underpin more effective and efficient imaging paradigms for many common tumours, and lead to a decrease in imaging costs.

Australia↗

PubMed2004

The Australian government's review of positron emission tomography: evidence-based policy-making in action.

The Commonwealth Government constituted the Medicare Services Advisory Committee (MSAC) to implement its commitment to entrench the principles of evidence-based medicine in Australian clinical practice. With its recent review of positron emission tomography (PETReview), the Commonwealth intervened in an established MSAC process, and sanctioned the stated objective to restrict expenditure on the technology. In our opinion: The evaluation of evidence by PETReview was fundamentally compromised by a failure to meet the terms of reference, poor science, poor process and unique decision-making benchmarks. By accepting the recommendations of PETReview, the Commonwealth is propagating information which is not of the highest quality. The use of inferior-quality information for decision-making by doctors, patients and policy-makers is likely to harm rather than enhance healthcare outcomes.

Australia↗

PubMed2004

Usefulness of fluorine-18 fluorodeoxyglucose positron emission tomography in patients with a residual structural abnormality after definitive treatment for squamous cell carcinoma of the head and neck.

BACKGROUND: Residual structural abnormalities after definitive treatment of head and neck squamous cell carcinoma (HNSCC) are common and pose difficult management problems. The usefulness of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) to supplement conventional evaluation with clinical and standard radiologic examination (CE) in such patients was assessed. METHODS: Fifty-three eligible patients were identified with residual structural abnormalities on CE. True disease extent could be validated in 46 patients. Patients had a median potential follow-up of 55 months (range, 41-75 months) from the date of PET scan to the analysis closeout date. RESULTS: PET had better diagnostic accuracy than CE (p = .0002) and induced management change in 21 patients (40%; 95% confidence interval [CI], 26%-54%), including avoidance of unnecessary planned surgery in 14 patients with negative PET. Appropriate management change was confirmed in 19 (95%) of 20 evaluable cases. Disease presence and extent assessment by PET were significant predictors of survival (p < .0001), whereas the extent of disease determined by CE was not. CONCLUSION: PET added significantly to the value of CE in restaging disease in patients with structural abnormalities after definitive treatment of HNSCC. Management decisions based on PET were appropriate in most patients.

Aged↗

PubMed2003

Review of efforts to decrease costly leg wound complications in the medicare population following coronary revascularization.

BACKGROUND: Current trends show that patients referred for coronary artery bypass grafting (CABG) are significantly older, sicker, and at higher risk for complications than ever before. Eliminating leg wound complications would significantly benefit these patients and reduce the consumption of health care time and dollars. Endoscopic vein harvesting (EVH) decreases the risk of wound complications in patients following CABG and may decrease costly long-term wound-related problems. METHODS: In this retrospective study, the cases of 1909 Medicare patients who had undergone EVH or open vein harvesting (OVH) for CABG were reviewed. The risk factors of these patients were examined and compared with those of 1485 non- Medicare patients. Readmissions, home health care costs, and office lengths of service were reviewed and analyzed. RESULTS: The results of univariate analyses of the Medicare versus non-Medicare populations indicated significant differences for peripheral vascular disease (25.4% versus 17.2%; P <.0001), renal failure (6.0% versus 2.8%; P <.0001), hypertension (75.4% versus 71.5%; P =.011), female sex (31.1% versus 22.4%; P <.0001), mean age (69.8 years versus 57.1 years; P <.0001), and mortality risk (4.6% versus 2.2%; P <.0001). The wound rates in the Medicare group were 1.1% for EVH (n = 741) versus 2.8% for OVH (n = 1168), and this difference was significant (P =.0163) despite a higher frequency of morbid obesity in the EVH population (P <.0001). No significant differences were found in readmission frequency, home health care costs, or office length of service. CONCLUSION: EVH benefits Medicare patients. Although this study is the largest to date to use disposable instruments, there is a lack of statistical power in the analysis of cost comparisons due to the small sample size of wound complications. However, there appears to be a general trend toward a lower treatment cost per patient and less resource use with EVH.

Aged↗

PubMed2002

Evaluation of high-risk melanoma: comparison of [18F]FDG PET and high-dose 67Ga SPET.

Recently the potential of whole-body positron emission tomography scanning using 18F-fluorodeoxyglucose (FDG PET) has led to renewed interest in the use of functional imaging for the detection of occult metastatic melanoma. This study compared dedicated FDG PET with high-dose gallium-67 imaging incorporating whole-body scanning and comprehensive single-photon emission tomography (SPET) in 122 cases (121 patients) in which the two scans were performed <6 weeks apart. All patients were at high clinical risk of occult metastatic disease and 49 (40%) had abnormality suggestive of metastatic disease by at least one functional imaging technique. Discrepant scan findings were followed up to determine which technique more accurately reflected disease status. There were 23/122 (19%; 95% CI: 12%-26%) cases with discordant scan results in respect of either the presence of melanoma (11 cases) or the extent of disease (12 cases). PET correctly identified more disease than 67Ga SPET in 14 cases (including three incidental primary tumours) and was true negative in three further patients with abnormal 67Ga SPET. There were six patients with true positive 67Ga SPET in whom FDG PET was false negative (one small cutaneous deposit, one residual axillary node rated equivocal on FDG PET due to postoperative changes, one adrenal metastasis inseparable from renal activity on FDG PET and three cases in which sites missed on FDG PET were seen on 67Ga SPET. Thus, FDG PET provided incremental diagnostic information compared with 67Ga SPET in 17/23 patients, while 67Ga SPET provided incremental information compared with PET in 6/23 cases ( P=0.035). Based on Australian Medicare reimbursement levels, the net cost per patient with clinical management benefit of replacing 67Ga SPET with FDG PET was estimated to be less than EUR 1,750. These results suggest that FDG PET provides incremental and clinically important information in around 10% of patients at a low incremental cost which, combined with greater patient convenience and lower radiation dosimetry, make FDG PET the functional imaging technique of choice for evaluation of suspected metastatic melanoma.

Adult↗

PubMed2002

The clinical impact of (18)F-FDG PET in patients with suspected or confirmed recurrence of colorectal cancer: a prospective study.

UNLABELLED: This prospective study aimed to confirm, in a clinical setting, the benefits suggested by earlier retrospective studies of (18)F-FDG PET scanning for the evaluation of patients with suspected recurrence of colorectal cancer. METHODS: The referring oncologist was asked to prospectively assign a treatment plan for 102 consecutive patients being evaluated by (18)F-FDG PET for suspected or confirmed recurrence of colorectal cancer and without evidence of unresectable disease on conventional staging investigations, including CT. This treatment plan was then compared with that based on incremental information supplied by PET. Management changes were validated by follow-up. RESULTS: For 6 patients, the oncologist would not commit to a management plan without access to PET information, and for all these patients, PET correctly guided management. Of the remaining 96 patients, the management plan for 54 (56%) was altered as a direct result of unexpected PET findings. Thus, PET directly influenced management in 60 (59%) of 102 patients. The discrepant PET results could be validated in 57 patients and were correct for both the presence and the extent of malignant disease in 52 (91%) of these patients but were false-positive in 1 patient because of a pelvic abscess and underestimated the extent of metastatic disease in 4 (7%). Relapse was confirmed in 49 (98%) of 50 evaluable patients with positive PET findings. Significantly, planned surgery was abandoned in 26 (60%) of 43 patients because of incremental PET findings. Of the 42 patients for whom management was not changed by PET findings, false-negative PET findings were documented for 5 (4 with metastases < 1 cm), and the PET findings for 1 were presumed to be false-positive because of sarcoidosis. CONCLUSION: This prospective study confirms the high impact, suggested by previous retrospective analyses, of (18)F-FDG PET on management of patients with suspected recurrent colorectal cancer. The major benefit of PET is avoidance of inappropriate local therapies by documentation of widespread disease.

Adult↗