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Val J Lowe

Publications and source records attributed to Val J Lowe.

At least 19 recordsLinked to original sources
PubMed2007

The utility of fluorodeoxyglucose positron emission tomography in the evaluation of carcinoid tumors presenting as pulmonary nodules.

BACKGROUND: Fluorodeoxyglucose positron emission tomography (FDG-PET) is sensitive for detection of neoplastic solitary pulmonary nodules but may have decreased sensitivity for detection of carcinoid tumors. Our purpose was to determine the sensitivity of FDG-PET to detect pulmonary carcinoid tumors. METHODS: We performed a retrospective review of our institutional results regarding FDG-PET in the setting of thoracic carcinoid neoplasms. We identified 16 patients with a pathologic diagnosis of bronchial carcinoid who had an antecedent FDG-PET (from 2000 to 2004). All patients but one presented with pulmonary nodule(s). RESULTS: Sixteen patients had a diagnosis of carcinoid tumor, typical in 11 patients and atypical in 5 patients. The mean greatest pathologic dimension was 2.08 cm (range, 1.0 to 8.3 cm). Overall positron emission tomography (PET) sensitivity was 75% (12 true-positive and 4 false-negative results). The mean (+/- SD) size of carcinoids with false-negative PET results was not significantly different from carcinoids with true-positive results (1.6 +/- 0.81 cm and 2.35 +/- 1.87 cm, p = 0.54). Fifteen of 16 patients were staged pathologically, and positive nodes were found in 2 of these patients. PET lymph node staging agreed with pathologic staging in one stage 4 patient with positive lymph nodes and distant metastasis, but PET results were false negative in the other patient who had N2 with micrometastatic disease; stage IIIA. CONCLUSIONS: FDG-PET imaging is useful for evaluation of typical and atypical thoracic carcinoid tumors. Although overall PET sensitivity for detection of carcinoid tumors is somewhat reduced as compared to non-small cell lung cancer, it is much higher than prior reports suggest.

Adult↗
PubMed2006

Characterization of the solitary pulmonary nodule: 18F-FDG PET versus nodule-enhancement CT.

OBJECTIVE: The purpose of this study was to directly compare nodule-enhancement CT and 18F-FDG PET in the characterization of indeterminate solitary pulmonary nodules (SPNs) greater than 7 mm in size. MATERIALS AND METHODS: Examinations from patients undergoing both nodule-enhancement CT and 18F-FDG PET to characterize the same indeterminate SPN were reviewed. For nodule-enhancement CT, an SPN was considered malignant when it showed an unenhanced to peak contrast-enhanced increase in attenuation greater than 15 H. Fluorine-18-FDG PET studies were blindly reinterpreted by two qualified nuclear radiologists. SPNs qualitatively showing hypermetabolic activity greater than the mediastinal blood pool were interpreted as malignant. These interpretations were compared with the original prospective clinical readings and to semiquantitative standardized uptake value (SUV) analysis. Results were compared with pathologic and clinical follow-up. RESULTS: Forty-two pulmonary nodules were examined. Twenty-five (60%) were malignant, and 17 (40%) were benign. Nodule-enhancement CT was positive in all 25 malignant nodules and in 12 benign nodules, with sensitivity and specificity of 100% and 29%, respectively, and with a positive predictive value (PPV) and negative predictive value (NPV) of 68% and 100%, respectively. Qualitative 18F-FDG PET interpretations were positive in 24 of the 25 malignant nodules and in four benign nodules. Fluorine-18-FDG PET was considered negative in one malignant nodule and in 13 of the 17 benign nodules. This correlates with a sensitivity and specificity of 96% and 76%, respectively, and with a PPV and NPV of 86% and 93%, respectively. Original prospective 18F-FDG PET and semiquantitative SUV analysis showed sensitivity, specificity, PPV, and NPV of 88%, 76%, 85%, and 81% and 84%, 82%, 88%, and 78%, respectively. CONCLUSION: Due to its much higher specificity and only slightly reduced sensitivity, 18F-FDG PET is preferable to nodule-enhancement CT in evaluating indeterminate pulmonary nodules. However, nodule-enhancement CT remains useful due to its high NPV, convenience, and lower cost. Qualitative 18F-FDG PET interpretation provided the best balance of sensitivity and specificity when compared with original prospective interpretation or SUV analysis.

Adult↗
PubMed2006

NEMA NU 2-2001 performance measurements of an LYSO-based PET/CT system in 2D and 3D acquisition modes.

UNLABELLED: The National Electrical Manufacturers Association (NEMA) NU 2-2001 performance measurements were conducted on the Discovery RX, a whole-body PET/CT system under development by GE Healthcare. The PET scanner uses 4.2 x 6.3 x 30 mm lutetium yttrium orthosilicate (LYSO) crystals grouped in 9 x 6 blocks. There are 24 rings with 630 crystals per ring and the ring diameter is 88.6 cm. The transaxial and axial fields of view are 70.0 and 15.7 cm, respectively. The scanner has retractable septa and can operate in both 2-dimensional (2D) and 3-dimensional (3D) modes. 2D acquisitions use ring differences of +/-4 for direct and +/-5 for cross slices; 3D acquisitions use a ring difference of 23. The coincident window width is 6.5 ns and the energy window is 425-650 keV. Other than the detectors, the system uses the same hardware and software as a Discovery ST. The CT scanner is a 16-slice LightSpeed; the performance characteristics of the CT component are not included herein. METHODS: Performance measurements of sensitivity, spatial resolution, image quality, scatter fraction and counting rate performance, and image quality were obtained using NEMA methodology. RESULTS: The system sensitivity in 2D and 3D was measured as 1.7 cps/kBq and 7.3 cps/kBq, respectively. The transaxial resolution for 2D (3D) was 5.1 mm full width at half maximum (FWHM) (5.0 mm) at 1 cm from gantry center and the radial and tangential resolutions were 5.9 mm (5.9 mm) and 5.1 mm (5.2 mm) at 10 cm, respectively. The axial resolution for 2D (3D) was 4.8 mm FWHM (5.8 mm) and 6.3 mm (6.5 mm) at 1 cm and 10 cm from gantry center, respectively. The scatter fraction was 13.1% and 31.8% in 2D and 3D. The peak noise equivalent count rate (NECR) was 155 kcps at 92.1 kBq/mL in 2D and 117.7 kcps at 21.7 kBq/mL in 3D for a noise-free estimation of randoms. The contrast of the 22, 17, 13, and 10 mm hot spheres in the image quality phantom in 2D (3D) were 74.6% (72.4%), 56.7% (59.5%), 46.2% (44.6%), and 17.9% (18.0%), respectively. CONCLUSION: The Discovery RX is a scanner that possesses high NECR, low scatter fraction, and good spatial resolution characteristics.

Equipment Design↗
PubMed2005

Etanercept therapy for immune-mediated cochleovestibular disorders: a multi-center, open-label, pilot study.

OBJECTIVE: Immune-mediated cochleovestibular disorders (IMCVDs) continue to present a diagnostic and therapeutic challenge. Antirheumatic agents, commonly employed for IMCVDs, are associated with variable efficacy and sometimes with serious side effects. The objective of the current study was to preliminarily evaluate the efficacy of etanercept therapy for IMCVD. METHODS: In this open-label prospective pilot study, 23 patients with bilateral IMCVDs or symptoms of bilateral Meniere's disease were treated with etanercept (25 mg twice weekly, by subcutaneous injection) for 24 weeks. All participants showed progressive hearing loss within 3 months prior to the study and responded to prednisone therapy. Hearing improvement was defined as an improvement of sensorineural hearing from baseline, in at least one ear, of 15 dB or more in the pure-tone air conduction thresholds, or an increase of more than 12% in word identification score. When present, vertigo and tinnitus were assessed by frequency and severity of attack and a functional level scale. Limited serial positron emission tomography (PET) of the inner ear region was performed in 5 patients to assess disease activity. RESULTS: There were 12 female (52%) and 11 male patients with a mean age of 48 years. Hearing improved in 7 (30%) patients, was unchanged in 13 (57%), and worsened in 3 (13%). Of 21 patients with tinnitus, this symptom improved in 7 (33%), was unchanged in 10 (48%), and worsened in 3 (13%). Of 16 patients with vertigo, 8 (50%) were improved, 7 (47%) unchanged, and 1 (3%) worse at the end of the study. Etanercept was generally well tolerated. PET was positive on one ear of 2 of 5 patients, remained positive with treatment on 1 of these, and was initially positive in 1 deaf ear, becoming negative at followup. CONCLUSION: These prospective pilot data suggest that etanercept therapy is safe among patients with IMCVDs. However, these data do not suggest substantial efficacy of etanercept among patients with IMCVDs in improving hearing loss. There appeared to be stabilization or improvement of hearing in 87% in this group of patients with pretreatment intractable progressive hearing loss. However, the study endpoint of improvement in 70% of patients was not attained. This short-term effect of possible stabilization requires further study. PET scanning was not useful as a tool to evaluate hearing loss in a limited subset of patients.

Adult↗
PubMed2005

Lung cancer screening experience: a retrospective review of PET in 22 non-small cell lung carcinomas detected on screening chest CT in a high-risk population.

OBJECTIVE: The objective of our study was to retrospectively review the PET results of non-small cell lung carcinomas detected on screening chest CT in a high-risk population. CONCLUSION: PET findings were negative in 32% of the cases of non-small cell carcinomas that were detected on screening CT in a high-risk patient population. These tumors were small, low-grade, or both. The most common histology was bronchioloalveolar cell carcinoma. The role of PET in evaluating screening-detected indeterminate nodules in a high-risk population may be more limited than in a general population.

Carcinoma, Non-Small-Cell Lung↗
PubMed2004

Metallopanstimulin as a marker for head and neck cancer.

BACKGROUND: Metallopanstimulin (MPS-1) is a ribosomal protein that is found in elevated amounts in the sera of patients with head and neck squamous cell carcinoma (HNSCC). We used a test, denoted MPS-H, which detects MPS-1 and MPS-1-like proteins, to determine the relationship between MPS-H serum levels and clinical status of patients with, or at risk for, HNSCC. PATIENTS AND METHODS: A total of 125 patients were prospectively enrolled from a university head and neck oncology clinic. Participants included only newly diagnosed HNSCC patients. Two control groups, including 25 non-smokers and 64 smokers, were studied for comparison. A total of 821 serum samples collected over a twenty-four month period were analyzed by the MPS-H radioimmunoassay. RESULTS: HNSCC, non-smokers, and smokers had average MPS-H values of 41.5 ng/mL, 10.2 ng/mL, and 12.8 ng/mL, respectively (p = 0.0001). CONCLUSION: We conclude that MPS-1 and MPS-1-like proteins are elevated in patients with HNSCC, and that MPS-H appears to be a promising marker of presence of disease and response to treatment in HNSCC patients.

Journal Article↗
PubMed2004

Applications of positron emission tomography imaging, intraoperative ultrasonography, magnetic resonance imaging, and angiography in the evaluation of renal masses.

Most renal masses and cysts are adequately characterized by ultrasonography or computerized tomography. Occasionally, further diagnostic evaluation is needed. Magnetic resonance imaging has emerged as the premier study to evaluate suspected tumor thrombus and to plan the operative technique in challenging cases. Intraoperative ultrasonography is a valuable real-time imaging modality for delineating tumor extent and margins during nephron-sparing surgery and in evaluating the presence of synchronous multifocality. Additionally, localized central renal tumors can be treated with ultrasonography-guided radiofrequency ablation. Positron emission tomography has little use in the diagnostic evaluation of renal masses, but may be useful in staging equivocal cases and in evaluating suspected recurrence or metastases in patients after nephrectomy for renal cell carcinoma.

Humans↗
PubMed2003

Positron emission tomography for basal cell carcinoma of the head and neck.

OBJECTIVE: To determine the ability of fluorodeoxyglucose F 18 positron emission tomography (FDG-PET) to image basal cell carcinoma (BCC). DESIGN: Case series study. SETTING: Mohs surgery practice in a tertiary university hospital. PATIENTS: Six patients with BCC larger than 1.0 cm of the head and neck region were identified. RESULTS: Patients were imaged using FDG-PET before surgery. In 3 patients, PET imaging correlated well with the size and extent of the soft tissue invasion. Histologically, all 3 tumors were of the nodular subtype. The remaining 3 patients failed to demonstrate identifiable tumor activity on PET. Two of these 3 tumors were of the infiltrative histologic subtype, and 1 was of the nodular subtype. Perineural spread was detected by tissue biopsy in 1 infiltrative tumor, but not by FDG-PET imaging. CONCLUSIONS: In our study, FDG-PET imaging was able to image and identify BCC in the head and neck region in 3 of 6 patients. In some cases, anatomic accuracy and the extent of soft tissue invasion were observed. The histologic subtype of the BCC appears to affect the ability of FDG-PET detection, with the nodular histologic subtype more likely to test positive on PET. This is a preliminary study, and future investigation is needed to evaluate the role of PET imaging in the management of patients with BCC.

Aged↗
PubMed2003

Positron emission tomography scanning in lung cancer.

Continuing advances in imaging technology have resulted in an improved ability to evaluate thoracic malignancies with PET. Published reports demonstrate that PET provides accurate, noninvasive detection of malignancy that is useful in the characterization of nonspecific radiographic lung lesions, staging of known lung cancer, and identification of recurrent disease. Preliminary studies suggest that PET may also be able to accurately assess therapeutic response. The incorporation of PET into routine clinical practice has advanced rapidly and undoubtedly PET will continue to be an increasingly important part of the clinical assessment of patients with lung malignancy.

Fluorodeoxyglucose F18↗
PubMed2003

The utility of positron emission tomography in the evaluation of autoimmune hearing loss.

OBJECTIVE: To evaluate positron emission tomography as an imaging tool in the diagnosis, evaluation, and management of autoimmune inner ear disease. BACKGROUND: Autoimmune inner ear disease is a form of cochleovestibular disease associated with variable hearing loss and vertigo for which no reliable diagnostic tests are available. METHODS: Pilot study of 10 patients with autoimmune inner ear disease and 5 sex-matched and age-matched control subjects without any history of autoimmune inner ear disease, who underwent limited positron emission tomography of the inner ear. Five patients with new or active autoimmune inner ear disease underwent serial positron emission tomography before and after 4 to 6 weeks of a high-dose tapering course of prednisone. The subjects had cranial magnetic resonance imagining, audiometric and vestibular studies, and heat-shock protein (HSP-70) measurements. Reading of the positron emission tomography scans was blinded. RESULTS: Positron emission tomography was normal in 4 of 5 normal control subjects and abnormal in 1 with normal audiometric and vestibular studies and positive HSP-70. Of patients with established and stable autoimmune inner ear disease, 4 of 5 had no positron emission tomography abnormalities and negative HSP-70, and the one with abnormal positron emission tomography shortly thereafter manifested clinically active disease. Of the 5 patients with active autoimmune inner ear disease monitored serially, 4 had an initial abnormal positron emission tomography in at least one ear, which became normal in all but 1 patient after therapy. HSP-70 correlated with disease activity. Only 1 patient with clinically active autoimmune inner ear disease had a normal positron emission tomography before and after therapy (the HSP-70 was positive before therapy and negative after the therapy). CONCLUSIONS: Positron emission tomography, especially when combined with HSP-70 determination, may be a useful technique for assessing disease in patients with autoimmune inner ear disease.

Adult↗
PubMed2003

Clinical 18F-FDG oncology patient preparation techniques.

OBJECTIVES: Clinical tumor imaging with (18)F-FDG in PET is growing in demand. This article will provide a review of current patient preparation and imaging techniques. The goal is to make the PET study as noninvasive as possible for the patient while obtaining quality images. Communication and coordination when scheduling these studies involves the patient and radiopharmacy, scanner, and support staff. A pertinent patient history (information about weight, pregnancy, breastfeeding, diabetes, etc.) is vital for appropriate patient instructions and patient sequencing. Patient preparation involves many variations on fluid intake, diet, medications, and other factors. Blood glucose levels must be </=150 mg/dL. If the patient has diabetes mellitus or is glucose intolerant, diet-exercise regime and glucose levels should be monitored. Accurate (18)F-FDG dose calculation to be used for region-of-interest analysis or standard uptake value determination is imperative. After (18)F-FDG injection, the patient must remain quiet and still to minimize muscle use. Before the scan, the patient may need relaxation medications, urinary catheterization, or other interventions. At the conclusion of this article, the reader should be able to list pertinent patient history issues that are useful for scheduling an (18)F-FDG tumor scan, discuss methods to ensure accurate (18)F-FDG patient dose calculations, and describe possible methods to help minimize urinary (18)F-FDG excretion.

Fluorine Radioisotopes↗
PubMed2003

18F-FDG PET of patients with Hürthle cell carcinoma.

UNLABELLED: Hürthle cell carcinoma is an uncommon differentiated thyroid cancer characterized by an aggressive clinical course and low avidity for (131)I. Treatment usually involves an aggressive surgical approach often combined with (131)I. (18)F-FDG PET has been helpful in the staging and evaluation of many types of aggressive malignancy. No reports to date have described the utility of PET in a series of patients with Hürthle cell cancer. We reviewed our experience with (18)F-FDG PET in the care of patients with Hürthle cell carcinoma to determine the likelihood of uptake in these cancers and the effect of (18)F-FDG PET on patient care. METHODS: Patients with Hürthle cell cancer who were seen between June 2000 and April 2002 and were imaged with (18)F-FDG PET were included. Imaging and clinical data were reviewed. PET results were compared with the results of anatomic imaging (CT, sonography, or MRI) and (131)I imaging when performed. Patient charts were reviewed to identify any change in management that resulted from the (18)F-FDG PET findings. RESULTS: Fourteen (18)F-FDG PET scans of 12 patients were obtained in the time frame indicated. All patients had documented Hürthle cell carcinoma. PET showed intense (18)F-FDG uptake in all known Hürthle cell cancer lesions but one. PET showed disease not identified by other imaging methods in 7 of the 14 PET scans. PET identified distant metastatic disease (5) or local disease (2) that was more extensive than otherwise demonstrated. In 7 of the 14 scans, the information provided by PET was used to guide or change therapy. CONCLUSION: Hürthle cell carcinoma demonstrates intense uptake on (18)F-FDG PET images. PET improves disease detection and disease management in patients with Hürthle cell carcinoma relative to anatomic or iodine imaging. (18)F-FDG PET should be recommended for the evaluation and clinical management of patients with Hürthle cell carcinoma.

Adenoma, Oxyphilic↗
PubMed2002

The usefulness of subtraction ictal SPECT coregistered to MRI in single- and dual-headed SPECT cameras in partial epilepsy.

PURPOSE: To prove the clinical usefulness of SISCOM and compare SISCOM images derived from single- and dual-headed single-photon computed tomography (SPECT) cameras for localization of partial epileptic seizures. METHODS: We retrospectively studied 38 partial epilepsy patients, using subtraction SPECT coregistered to magnetic resonance imaging (MRI; SISCOM). SPECT imaging of the first 15 patients was performed by single-headed camera, and the next 23 patients by dual-headed camera. Side-by-side ictal-interictal SPECT evaluation and SISCOM images were blindly reviewed and classified as either localizing to one of 16 sites or nonlocalizing. A third reviewer evaluated cases of disagreement between primary reviewers. Results were compared with seizure localization by any of the following three traditional techniques: surgical outcome, invasive, and noninvasive video-EEG monitoring. The results from the single- and dual-headed SPECT cameras were compared. RESULTS: Reviewers localized areas of hyperperfusion with SISCOM images more often than with side-by-side SPECT evaluation (71.0 vs. 47.4%; p = 0.01). When we compared results of SPECT evaluation with traditional techniques, SISCOM showed greater concordance than side-by-side SPECT evaluation (60.53 vs. 36.84%; p = 0.006). There were no differences in localization between images derived from single- and dual-headed cameras. Concordance of seizure localization, compared with traditional techniques, also was not different between these groups [kappa = 0.38, 95% confidence interval (CI), 0.18-0.58] vs. kappa = 0.63, 95% CI (0.45-0.81)]. CONCLUSIONS: SISCOM is a worthwhile technique for preoperative evaluation in partial epilepsy patients and improves the sensitivity and specificity of seizure localization of SPECT images derived from both single- and dual-headed SPECT cameras.

Adolescent↗
PubMed2002

Cholangiocarcinoma metastatic to the neck: first report of a case.

We describe a unique case of a cholangiocarcinoma that metastasized to a cervical lymph node--to our knowledge the only such case ever reported. The diagnosis was based on fine-needle aspiration cytology and confirmed by excision biopsy. This case illustrates the importance of keeping all possible options in mind when diagnosing head and neck masses.

Bile Duct Neoplasms↗