ORCID Profile
0000-0001-6928-7378
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Publisher: American Society of Hematology
Date: 05-1998
DOI: 10.1182/BLOOD.V91.9.3340.3340_3340_3346
Abstract: Positron emission tomography (PET) is a whole-body imaging technique using 18 fluorine-fluorodeoxyglucose (FDG), whose uptake is increased in tumor cells. Published studies have shown PET to be an effective method of staging lymphoma and to be more sensitive than CT at detecting extranodal disease. The purpose of this study was to determine whether the increased marrow uptake of FDG observed in some lymphoma patients during routine staging PET scans represented marrow involvement by disease. PET scans of 50 patients with Hodgkin's (12) and non-Hodgkin's (38) lymphoma were analyzed by three independent observers and the marrow graded as normal or abnormal using a visual grading system. Unilateral iliac crest marrow aspirates and biopsies were performed on all patients. The PET scan and marrow histology agreed in 39 patients (78%), being concordant positive in 13 and concordant negative in 26 patients. In 8 patients the PET scan showed increased FDG uptake but staging biopsy was negative in 4 of these 8 patients the PET scan showed a normal marrow background with focal FDG “hot spots” distant from the site biopsied. In 3 patients the marrow biopsy specimen was positive but the PET scan normal 2 of these 3 patients had non-Hodgkin's lymphoma whose malignant cells did not take up FDG at lymph node or marrow disease sites. Therefore, there were only 5 patients (10%) in whom there was a difference between the PET scan and biopsy result which could not be fully explained. Visual interpretation of marrow FDG uptake during whole-body staging PET scans can correctly assess marrow disease status in a high proportion of lymphoma patients. PET has the potential to reduce the need for staging marrow biopsy.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 03-1999
DOI: 10.1016/S0003-4975(98)01257-0
Abstract: Surgical resection of lung cancer remains the treatment of choice in appropriately staged disease, but conventional imaging techniques have limitations. Positron emission tomography (PET) may improve staging accuracy. We studied whole body and localized thoracic PET in staging lung cancer. Standardized uptake value was calculated for the primary lesion. Ninety-seven patients under consideration for surgical resection were included. PET, computed tomography, and clinical staging were compared to stage at operation, biopsy, or final outcome. Mean follow up was 17.5 months. PET detected all primary lung cancers with two false-positive primary sites. Sensitivity and specificity for N2 and N3 mediastinal disease was 20% and 89.9% for computed tomography and 70.6% and 97% for PET. PET correctly altered stage in 26.8%, nodal stage in 13.4%, and detected distant metastases in 16.5%. PET missed 7 of 10 cerebral metastases. PET altered management in 37% of patients. PET staging (p<0.0001) and standardized uptake value (p<0.001) were the best predictors of time to death apart from operative staging. PET provides significant staging and prognostic information in lung cancer patients considered operable by standard criteria. Routine use of PET will prevent unnecessary operation and may be cost effective.
Publisher: Informa UK Limited
Date: 1997
Abstract: Positron emission tomography (PET) scanning adds a functional dimension to brain scanning levels of metabolic activity are imaged and this information may complement the more "anatomic" imaging of CT and MRI. In a series of 10 young patients the usefulness of PET scanning technique was investigated. The major areas of usefulness were the distinction of posttreatment sequelae from active tumour (both postsurgical MRI changes from tumour and postradiation MRI changes from tumour) and the localization of persisting tumour amenable to radiosurgical treatment. The technique was beneficial in assessing continuing activity in pineal tumours (residual pineal teratoma mass and residual pineocytoma mass) and in assessing activity in brainstem/cerebellar peduncle gliomas (three cases). In one unusual case of widespread leptomeningeal melanoma, the PET scan under-read the situation.
Publisher: Oxford University Press (OUP)
Date: 10-2000
DOI: 10.1016/S1010-7940(00)00535-2
Abstract: Positron emission tomography (PET) is being increasingly used as an accurate and non-invasive modality in diagnosis, staging and post-therapy assessment in patients with lung cancer. In this study, we examine whether the uptake of [(18)F]fluorodeoxyglucose (FDG), a marker of increased glucose metabolism in neoplastic cells, is of prognostic value in patients with primary lung cancer. We have retrospectively analyzed 77 patients (mean age, 63. 0 years male/female ratio, 53:24) with primary lung cancers who underwent whole body and localized thoracic PET as part of their diagnostic and staging procedures prior to consideration of surgical resection. The standardized uptake value (SUV) of injected FDG for each primary lesion was correlated with tumour histology and the patient's clinical outcome. A SUV of 20 or greater was found to be of significant prognostic value. The chance of survival (with 95% confidence intervals (CI)) at 12 months post-surgery for the various SUV groups was as follows: 75.2% (59.6-85.5) for SUV<10 67.5% (29.0-88.2) for SUV 10-<12 63.6% (29.7-84.5) for SUV 12-<15 66.7% (19.5-90.4) for SUV 15- 20. A SUV of 20 or more is associated with a 4.66 times increase in hazard, compared with lower levels of SUV. We found no significant correlation between tumour histology and SUV. We have previously reported on the significant advantages of PET in the staging and surgical care of patients with lung cancer. The present study adds further support for an additional prognostic role for PET in the management of thoracic malignancy as determined by the amount of labelled-FDG taken up by the primary lesion.
Publisher: Cambridge University Press (CUP)
Date: 03-1998
DOI: 10.1017/S0022215100158438
Abstract: The assessment of head and neck cancer has traditionally involved clinical examination and anatomical imaging by computed tomography (CT) or magnetic resonance imaging (MRI). We present a case where a problem of clinical confusion and inconclusive radiology was resolved by the use of positron emission tomography (PET) coregistered with CT.
Publisher: Society of Nuclear Medicine
Date: 19-06-2014
Abstract: Although incidental pituitary findings on (18)F-FDG PET are uncommon, there are several reports published in the literature. It is believed that this is the first reporting of incidental pituitary disease found on O-(2-(18)F-fluoroethyl)-l-tyrosine ((18)F-FET) PET imaging. The case provides valuable insight into pathogenesis, diagnostic tools, and related pathology. The power of (18)F-FET in differentiating cerebral metastases and recurrence in patients who had previous surgical and radiation therapy is highlighted, and the incremental benefits over MR imaging and (18)F-FDG PET are outlined. The case represents an uncommon finding on MR imaging and (18)F-FDG PET and a rare finding on (18)F-FET PET.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 11-2018
DOI: 10.1200/PO.17.00221
Abstract: Low-grade serous ovarian carcinoma (LGSC) responds poorly to chemotherapy and is characterized by activating mutations in the Ras sarcoma–mitogen-activated protein kinase (RAS-MAPK) pathway, including oncogenic BRAF. However, response to BRAF inhibitors is tumor-type specific. Significant improvement in survival is seen in patients with BRAF-mutant melanoma, but other cancer types, such as colorectal cancers, are generally less sensitive. We examined the frequency and characteristics of BRAF-mutated LGSC and described the response to treatment with BRAF inhibitors. Mutations were assessed in LGSC (N = 65) by using targeted, exome, and whole-genome sequencing. Patient characteristics, treatment, and clinical outcome were assessed, and the median follow-up time was more than 5 years. BRAF inhibitors were trialed in two patients with a somatic BRAF V600E mutation: one patient received dabrafenib monotherapy and was monitored clinically, biochemically (cancer antigen [CA]-125 levels), and with positron emission tomography (PET) imaging. Expression of the BRAF V600E protein in this patient was assessed by immunohistochemistry. Among patients with LGSC, nine (13.8%) of 65 had a somatic BRAF mutation. Of the nine patients with BRAF mutation–positive LGSC, four experienced progressive disease that did not respond to conventional chemotherapy. Two of the patients experienced progression quickly and died as a result of disease progression, and two received targeted treatment. Two patients with BRAF V600E mutation received BRAF inhibitors at relapse and both achieved durable responses. BRAF mutations are not uncommon in patients with LGSC and should be routinely tested, because BRAF inhibitors can be an effective treatment for these patients. The results highlight the need for targeted treatment in this rare tumor type, and a prospective study is needed to formally assess the response rate and clinical benefit.
Publisher: Elsevier BV
Date: 2013
DOI: 10.1016/J.EJCA.2012.08.018
Abstract: Little is known about the prevalence and clinical significance of heterogeneity of positron emission tomography with (18)F-labelled fluorodeoxyglucose-positron emission tomography (FDG-PET) response. We aim to determine the prevalence, and clinicopathologic correlates of intra-patient heterogeneity of FDG-PET response in metastatic melanoma treated with dabrafenib, and to determine whether heterogeneity predicts clinical outcome. Patients with BRAF mutant metastatic melanoma and ≥ 2 FDG avid lesions treated on the Phase I trial of dabrafenib at a single institution (n=23) were included. FDG-PET response was assessed by comparing baseline PET scans with scans at day 15. A heterogeneous response was defined as responding and new or metabolically progressing lesion(s) in a patient, or >10% of lesions with a stable metabolic response and responding lesions in a patient. Six (26%) patients had a heterogeneous PET response. The median time to progression (TTP) was 7.4 months (95% confidence interval (CI): 6.5-8.3) for PET homogeneous responders and 3.0 months (95%CI: 0.6-5.4) for PET heterogeneous responders. There were no homogeneous non-responders. Age, BRAF mutation genotype, dose, and lactate dehydrogenase, did not predict for heterogeneity of PET response. Heterogeneity did not correlate with tumour response. Lung metastases were more likely to respond than other visceral metastatic sites. Heterogeneous FDG-PET responses are common in metastatic melanoma treated with dabrafenib, and heterogeneity is associated with a shorter TTP. FDG-PET heterogeneity may predict molecular heterogeneity, and FDG-PET directed biopsies may facilitate investigation into mechanisms of resistance to signal pathway inhibitors.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 10-04-2015
Publisher: American Association for Cancer Research (AACR)
Date: 07-2013
DOI: 10.1158/1535-7163.MCT-13-0011
Abstract: Inhibitors of the mitogen-activated protein kinases (MAPK), BRAF, and MAP–ERK kinase (MEK) induce tumor regression in the majority of patients with BRAF-mutant metastatic melanoma. The clinical benefit of MAPK inhibitors is restricted by the development of acquired resistance with half of those who benefit having progressed by 6 to 7 months and long-term responders uncommon. There remains no agreed treatment strategy on disease progression in these patients. Without published evidence, fears of accelerated disease progression on inhibitor withdrawal have led to the continuation of drugs beyond formal disease progression. We now show that treatment with MAPK inhibitors beyond disease progression can provide significant clinical benefit, and the withdrawal of these inhibitors led to a marked increase in the rate of disease progression in two patients. We also show that MAPK inhibitors retain partial activity in acquired resistant melanoma by examining drug-resistant clones generated to dabrafenib, trametinib, or the combination of these drugs. All resistant sublines displayed a markedly slower rate of proliferation when exposed to MAPK inhibitors, and this coincided with a reduction in MAPK signaling, decrease in bromodeoxyuridine incorporation, and S-phase inhibition. This cytostatic effect was also associated with diminished levels of cyclin D1 and p-pRb. Two short-term melanoma cultures generated from resistant tumor biopsies also responded to MAPK inhibition, with comparable inhibitory changes in proliferation and MAPK signaling. These data provide a rationale for the continuation of BRAF and MEK inhibitors after disease progression and support the development of clinical trials to examine this strategy. Mol Cancer Ther 12(7) 1332–42. ©2013 AACR.
Publisher: Informa UK Limited
Date: 1998
Abstract: 18-FDG and 11C methionine PET scans were performed on two patients with gliomatosis cerebri. The cortical grey matter was hypometabolic when compared with normal. The findings support the concept that the cerebral cortex becomes functionally disconnected in this disease owing to the infiltrative nature of the underlying tumour. This may account for the high incidence of dementia in the course of this disease. In one of the cases described here, there was clear evidence of progression from a discrete tumour mass of glioma to gliomatosis cerebri and this progression argues against the WHO classification of this disorder separately from glioma.
Publisher: Wiley
Date: 13-06-2006
Publisher: Springer Science and Business Media LLC
Date: 16-10-2001
Abstract: In rare cases, extrarenal uptake of technetium-99m diethylenetriamine penta-acetic acid ((99m)Tc-DTPA) has been reported, e.g. in tumours or abscesses. Although in our experience a relatively common occurrence, increased uptake in the left iliac fossa (LIF) and its incidence have not been described. This retrospective study set out to establish the incidence of this phenomenon and to exclude malignancy as the cause. All patients who had a renal (99m)Tc-DTPA scan between 1 January 1996 and 31 December 1997 had their scans reviewed. Presence and grade of increase in iliac fossa activity were determined by consensus agreement of three observers. The list of patients with increased uptake was cross-referenced against the New South Wales (Australia) Cancer Council database to exclude the possibility of a neoplastic lesion in this region. Increased LIF uptake was noted in 41 of the 231 (18%) consecutive patients (18 men, 23 women mean age 43 years, range 20-83). Among these 41 patients, uptake was severe in 2 (5%), moderate in 12 (29%) and mild in 27 (66%). No patient had increased uptake in the right iliac fossa. Only one patient had a malignant lesion but this was excluded as being the cause of LIF uptake. No other patient developed malignancy (mean follow-up time 4.1 years range 3.2-5.1). Increase in LIF uptake is a common, benign finding most likely due to activity within the descending colon. It occurs in approximately 18% of the population, and it is important to recognise such uptake in order to avoid misdiagnoses.
Publisher: Wiley
Date: 04-08-2016
DOI: 10.1111/PCMR.12503
Abstract: 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) scans were performed on 27 patients with unresectable stage IIIC or IV melanoma after prolonged treatment with anti-PD-1 antibodies to examine the hypothesis that patients with prolonged response to treatment may have metabolically inactive lesions by FDG-PET. Scans were performed at a median of 15.2 months (range 12-29 months) after starting treatment. Overall, 15 of 27 (56%) patients had a positive FDG-PET scan. Eight patients with positive scans underwent biopsy 5 of 8 (62%) were melanoma and 3 of 8 (38%) were immune cell infiltrates. Of the 12 patients with negative FDG-PET scans, six had residual computerized tomography-visible lesions, five have ceased treatment, and none have recurred with follow-up of 6-10 months. Patients with residual metastases after a prolonged period without progression on anti-PD-1 therapy may have metabolically inactive lesions. Isolated metabolically active lesions in clinically well patients may reveal immune cell infiltrates rather than melanoma.
No related grants have been discovered for Catherine AB Saunders.