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PubMedDate not supplied

Accuracy of nursing diagnoses: concept development.

The concept of accuracy of nursing diagnoses was developed by the author as a first step of theory development related to nursing diagnosis. Accuracy is conceptually redefined as a continuous variable and a such contrasts with the prevailing view of accuracy that diagnoses are either accurate or inaccurate. The conceptual definition of accuracy of a nursing diagnosis and a delineation of the characteristics of accuracy emphasize the relativistic nature of the concept.

Concept Formation↗
PubMed2003

Near-infrared fluorescence contrast-enhanced imaging with intensified charge-coupled device homodyne detection: measurement precision and accuracy.

Fluorescence frequency-domain photon migration (FDPM) through tissue refers to the propagation of intensity-modulated fluorescent light that originates from tissue-laden fluorophores following illumination with an intensity-modulated excitation light source. FDPM measurements of modulation amplitude and phase are ultimately employed in an inversion algorithm for tomographic reconstruction of interior optical and fluorescent property maps that delineate disease enhanced with fluorescent contrast agent. Because the inverse problem is underdetermined, measurement precision and accuracy crucially impact its solution. Reported here are the precision and accuracy of FDPM measurements acquired using an intensified CCD homodyne detection system. By introducing 32 phase delays between the oscillators used to modulate the intensifier gain and light source intensity at 100 MHz, mean precision is maximized at +/-0.46% and +/-0.26 deg for measurements of modulation amplitude and phase, respectively. Measurement precision improves when the number of phase delays increases. Measurements of fluorescence modulation amplitude and phase, acquired from the surface of a tissue phantom at distances ranging between 0.71 and 3.6 cm from an incident excitation point source, exhibit a mean accuracy of 17% and 1.9 deg, respectively. Measurement accuracy deteriorates with increasing distance from the point source, but for distances up to 1.0 cm from the point source, measurements of fluorescence modulation amplitude and phase exhibit a mean accuracy of 5.4% and 0.30 deg, respectively.

Breast Neoplasms↗
PubMed2003

A phantom study on the positioning accuracy of the Novalis Body system.

A phantom study was conducted to investigate inherent positioning accuracy of an image-guided patient positioning system-the Novalis Body system for three-dimensional (3-D) conformal radiotherapy. This positioning system consists of two infrared (IR) cameras and one video camera and two kV x-ray imaging devices. The initial patient setup was guided by the IR camera system and the target localization was accomplished using the kV x-ray imaging system. In this study, the IR marker shift and phantom rotation were simulated and their effects on the positioning accuracy were examined by a Rando phantom. The effects of CT slice thickness and treatment sites on the positioning accuracy were tested. In addition, the internal target shift was simulated and its effect on the positioning accuracy was examined by a water tank. With the application of the Novalis Body system, the positioning error of the planned isocenter was significantly reduced. The experimental results with the simulated IR marker shifts indicated that the positioning errors of the planned isocenter were 0.6 +/- 0.3, 0.5 +/- 0.2, and 0.7 +/- 0.2 mm along the lateral, longitudinal, and vertical axes, respectively. The experimental results with the simulated phantom rotations indicated that the positioning errors of the planned isocenter were 0.6 +/- 0.3, 0.7 +/- 0.2, and 0.5 +/- 0.2 mm along the three axes, respectively. The experimental results with the simulated target shifts indicated that the positioning errors of the planned isocenter were 0.6 +/- 0.3, 0.7 +/- 0.2, and 0.5 +/- 0.2 mm along the three axes, respectively. On average, the positioning accuracy of 1 mm for the planned isocenter was achieved using the Novalis Body system.

Equipment Failure Analysis↗
PubMed2000

Quality assurance of beam accuracy for Leksell Gamma Unit.

For the acceptance test and annual quality assurance of the Leksell Gamma Unit, measurement of the beam accuracy, defined as a distance between mechanical and radiological isocenters, poses a challenge to medical physicists. The specification for the beam accuracy is within 0.5 mm for the 4-mm collimator helmet. In this report, we introduce a simple technique to analyze the beam accuracy by using a conventional film densitometer plus mathematical modeling. A small piece of film was placed inside the film cassette containing a sharp needle. The needle is located such that its tip is exactly positioned at the mechanical isocenter. Before exposure, the film was pierced by the needle. Density profile was measured by using a densitometer with a spatial resolution of 0.8 mm. The profile was then fitted to a model of the two Gaussian functions. One is for the radiation field profile, the other for a dip caused by the narrow hole. The difference between the centers of the two Gaussian functions defines the deviation of the beam accuracy from the mechanical center of the unit. The deviations for x, y, and z directions from one of our annual measurements are 0.032, 0.054, and 0.195 mm, respectively. The combined deviation is 0.20 mm, which is well within the specification and in excellent agreement with the results from the manufacture's laser measurement. This technique provides a simple, accurate and practical tool for measurement of the beam accuracy in the acceptance test and annual quality assurance of the Leksell Gamma Unit.

Film Dosimetry↗
PubMed2003

Accuracy of the TRUGENE HIV-1 genotyping kit.

Drug resistance and poor virological responses are associated with well-characterized mutations in the viral reading frames that encode the proteins that are targeted by currently available antiretroviral drugs. An integrated system was developed that includes target gene amplification, DNA sequencing chemistry (TRUGENE HIV-1 Genotyping Kit), and hardware and interpretative software (the OpenGene DNA Sequencing System) for detection of mutations in the human immunodeficiency virus type 1 (HIV-1) protease and reverse transcriptase sequences. The integrated system incorporates reverse transcription-PCR from extracted HIV-1 RNA, a coupled amplification and sequencing step (CLIP), polyacrylamide gel electrophoresis, semiautomated analysis of data, and generation of an interpretative report. To assess the accuracy and robustness of the assay system, 270 coded plasma specimens derived from nine patients were sent to six laboratories for blinded analysis. All specimens contained HIV-1 subtype B viruses. Results of 270 independent assays were compared to "gold standard" consensus sequences of the virus populations determined by sequence analysis of 16 to 20 clones of viral DNA amplicons derived from two independent PCRs using primers not used in the kit. The accuracy of the integrated system for nucleotide base identification was 98.7%, and the accuracy for codon identification at 54 sites associated with drug resistance was 97.6%. In a separate analysis of plasma spiked with infectious molecular clones, the assay reproducibly detected all 72 different drug resistance mutations that were evaluated. There were no significant differences in accuracy between laboratories, between technologists, between kit lots, or between days. This integrated assay system for the detection of HIV-1 drug resistance mutations has a high degree of accuracy and reproducibility in several laboratories.

Anti-HIV Agents↗
PubMed2006

Accuracy of GDx VCC, HRT I, and clinical assessment of stereoscopic optic nerve head photographs for diagnosing glaucoma.

AIMS: To determine and compare the accuracy and reproducibility of GDx variable cornea compensation (VCC) scanning laser polarimetry (SLP) with VCC, Heidelberg retina tomograph (HRT) I confocal scanning laser ophthalmoscopy (CSLO), and clinical assessment of stereoscopic optic nerve head (ONH) photographs for diagnosing glaucoma. METHODS: One eye each of 40 healthy subjects, 48 glaucoma patients, and six patients with ocular hypertension were measured with SLP-VCC and CSLO. Simultaneous stereoscopic ONH photographs were also obtained. Sixteen photographs of healthy and glaucomatous eyes were duplicated for assessing intraobserver agreement. Four glaucoma specialists, four general ophthalmologists, four residents in ophthalmology, and four optometrists classified the ONH photographs as normal or glaucomatous. For SLP-VCC, the nerve fiber indicator (NFI) was evaluated. For CSLO, the Moorfields regression analysis (MRA) and the Bathija linear discriminant function (LDF) were used. Sensitivity, specificity, percentage of correctly classified eyes, and intra- and interobserver agreement, expressed as kappa (kappa) were calculated. RESULTS: SLP-VCC had the highest diagnostic accuracy, with a sensitivity, specificity, and overall correct classification of 91.7%, 95.0% and 93.2%, respectively. CSLO, expressed as Bathija LDF and MRA, had a diagnostic accuracy comparable to glaucoma specialists and general ophthalmologists with an overall accuracy of 89.8%, 86.4%, 86.7% and 85.2%, respectively. Residents classified the fewest eyes correctly. Intraobserver agreement for classifying the ONH photographs ranged between 0.48 (within residents) and 0.78 (within glaucoma specialists). The interobserver agreement ranged between 0.45 (between residents) and 0.74 (between glaucoma specialists). The agreement between observers and CSLO MRA (kappa, 0.68) was statistically significantly higher (p<0.001; paired t-test) than between observers and SLP-VCC NFI (kappa, 0.60) and CSLO Bathija LDF (kappa, 0.62). CONCLUSION: Automated analysis of measurements with GDx VCC and HRT had a similar diagnostic accuracy for glaucoma as classification of stereoscopic ONH photographs by glaucoma specialists, thus bringing all eye-care professionals to this desirable level. The intra- and interobserver agreement for ONH analysis was only moderate to good. We think these imaging techniques may assist clinicians in diagnosing glaucoma.

Adult↗
PubMed2006

Sample sizes of studies on diagnostic accuracy: literature survey.

OBJECTIVES: To determine sample sizes in studies on diagnostic accuracy and the proportion of studies that report calculations of sample size. DESIGN: Literature survey. DATA SOURCES: All issues of eight leading journals published in 2002. METHODS: Sample sizes, number of subgroup analyses, and how often studies reported calculations of sample size were extracted. RESULTS: 43 of 8999 articles were non-screening studies on diagnostic accuracy. The median sample size was 118 (interquartile range 71-350) and the median prevalence of the target condition was 43% (27-61%). The median number of patients with the target condition--needed to calculate a test's sensitivity--was 49 (28-91). The median number of patients without the target condition--needed to determine a test's specificity--was 76 (27-209). Two of the 43 studies (5%) reported a priori calculations of sample size. Twenty articles (47%) reported results for patient subgroups. The number of subgroups ranged from two to 19 (median four). No studies reported that sample size was calculated on the basis of preplanned analyses of subgroups. CONCLUSION: Few studies on diagnostic accuracy report considerations of sample size. The number of participants in most studies on diagnostic accuracy is probably too small to analyse variability of measures of accuracy across patient subgroups.

Confidence Intervals↗
PubMed2005

Diagnostic accuracy of B type natriuretic peptide and amino terminal proBNP in the emergency diagnosis of heart failure.

OBJECTIVE: To compare head to head the diagnostic accuracy of B type natriuretic peptide (BNP) and the amino terminal fragment of its precursor hormone (NT-proBNP) for congestive heart failure (CHF) in an emergency setting. METHODS: 251 consecutive patients presenting to the emergency department with dyspnoea as a chief complaint were prospectively studied. Patients with acute coronary syndromes were excluded. The diagnosis of CHF was based on the Framingham score for CHF plus echocardiographic evidence of systolic or diastolic dysfunction. Blood concentrations of BNP and NT-proBNP were measured by two commercially available assays (Abbott and Roche methods). The diagnostic accuracies of BNP and NT-proBNP were assessed by receiver operating characteristic curve analysis. RESULTS: Areas under the curve for BNP and NT-proBNP in patients with dyspnoea caused by CHF (n = 137) and in patients with dyspnoea attributable to other reasons (n = 114) did not differ significantly (area under the curve 0.916 v 0.903, p = 0.277, statistical power 94%). Cut off concentrations with the highest diagnostic accuracy were 295 ng/l for BNP (sensitivity 80%, specificity 86%, diagnostic accuracy 83%) and 825 ng/l for NT-proBNP (sensitivity 87%, specificity 81%, diagnostic accuracy 84%). Evaluation of discordant false classifications at these cut off concentrations showed no advantage for either BNP nor NT-proBNP in the biochemical diagnosis of CHF (17 misclassifications by BNP and 14 by NT-proBNP, p = 0.720). In the population studied, age, sex, and renal function had no impact on the diagnostic utility of both tests when compared by logistic regression models. CONCLUSIONS: BNP and NT-proBNP may be equally useful as an aid in the diagnosis of CHF in short of breath patients presenting to the emergency department.

Aged↗
PubMedDate not supplied

The accuracy of medication data in an outpatient electronic medical record.

OBJECTIVE: To measure the accuracy of medication records stored in the electronic medical record (EMR) of an outpatient geriatric center. The authors analyzed accuracy from the perspective of a clinician using the data and the perspective of a computer-based medical decision-support system (MDSS). DESIGN: Prospective cohort study. METHODS: The EMR at the geriatric center captures medication data both directly from clinicians and indirectly using encounter forms and data-entry clerks. During a scheduled office visit for medical care, the treating clinician determined whether the medication records for the patient were an accurate representation of the medications that the patient was actually taking. Using the available sources of information (the patient, the patient's vials, any caregivers, and the medical chart), the clinician determined whether the recorded data were correct, whether any data were missing, and the type and cause for each discrepancy found. RESULTS: At the geriatric center, 83% of medication records represented correctly the compound. dose, and schedule of a current medication; 91% represented correctly the compound. 0.37 current medications were missing per patient. The principal cause of errors was the patient (36.1% of errors), who misreported a medication at a previous visit or changed (stopped, started, or dose-adjusted) a medication between visits. The second most frequent cause of errors was failure to capture changes to medications made by outside clinicians, accounting for 25.9% of errors. Transcription errors were a relatively ucommon cause (8.2% of errors). When the accuracy of records from the center was analyzed from the perspective of a MDSS, 90% were correct for compound identity and 1.38 medications were missing or uncoded per patient. The cause of the additional errors of omission was a free-text "comments" field-which it is assumed would be unreadable by current MDSS applications-that was used by clinicians in 18% of records to record the identity of the medication. CONCLUSIONS: Medication records in an outpatient EMR may have significant levels of data error. Based on an analysis of correctable causes of error, the authors conclude that the most effective extension to the EMR studied would be to expand its scope to include all clinicians who can potentially change medications. Even with EMR extensions, however, ineradicable error due to patients and data entry will remain. Several implications of ineradicable error for MDSSs are discussed. The provision of a free-text "comments" field increased the accuracy of medication lists for clinician users at the expense of accuracy for a MDSS.

Aged↗
PubMed1994

Genital ulcer disease: accuracy of clinical diagnosis and strategies to improve control in Durban, South Africa.

OBJECTIVE: To investigate the accuracy of clinical diagnosis in genital ulcer disease (GUD); to devise management strategies for improving the control of GUD and thereby limit the spread of HIV-1 infection. DESIGN: Clinical and microbiological assessment of GUD in men and women. The index of suspicion, diagnostic accuracy, diagnostic efficiency and positive and negative predictive values of a clinical diagnosis were investigated. SETTING: City Health Sexually Transmitted Diseases Clinic, King Edward VIII Hospital, Durban, South Africa. PARTICIPANTS: 100 men and 100 women with genital ulcers. RESULTS: The accuracy of a clinical diagnosis was, in men: lymphogranuloma venereum (LGV) 66%, donovanosis 63%, chancroid 42%, genital herpes 39%, primary syphilis 32%, mixed infections 8%, and in women; secondary syphilis 94%, donovanosis 83%, genital herpes 60%, primary syphilis 58%, chancroid 57%, LGV 40%, mixed infections 14%. Overall, diagnostic efficiency was greater in women than in men. When compared with other causes of GUD, donovanosis ulcers bled to the touch and were larger and not usually associated with inguinal lymphadenopathy. In women, extensive vulval condylomata lata were readily differentiated from all other causes of GUD. CONCLUSION: A clinical diagnosis in genital ulceration was less accurate in men than in women. The diagnostic accuracies for donovanosis and secondary syphilis were relatively high but for most other conditions were low. Differences between clinical and laboratory diagnostic accuracies may reflect similarities between the clinical appearances of the various causes of GUD, the presence of mixed infections, atypical ulceration due to longstanding disease, and insensitive laboratory tests. In this community all large ulcers should be treated empirically for syphilis and donovanosis. Uncircumcised men with GUD are an important HIV core or "superspreader" group locally, and prevention strategies should include counselling and health education in the light of the inaccuracy of clinical diagnosis found in this study. The development of rapid accurate tests for GUD is urgently required.

Chancroid↗
PubMed2000

Toward a psychology of memory accuracy.

There has been unprecedented interest in recent years in questions pertaining to accuracy and distortion in memory. This interest, catalyzed in part by real-life problems, marks a significant departure from the quantity-oriented approach that has characterized much of traditional memory research. We outline a correspondence metaphor of memory underlying accuracy-oriented research, and show how the features of this metaphor are manifested across the disparate bodies of research reviewed here. These include work in the Gestalt tradition, spatial memory, memory for gist, schema theory, source monitoring, fluency misattributions, false recall and recognition, postevent misinformation, false memories, eyewitness research, and autobiographical memory. In examining the dynamics of memory accuracy, we highlight the importance of metacognitive monitoring and control processes. We end by discussing some of the methodological, theoretical, and metatheoretical issues inherent in accuracy-oriented research, attempting to prepare the groundwork for a more coherent psychology of memory accuracy.

Humans↗
PubMed2004

Preoperative T and N staging of colorectal cancer: accuracy of contrast-enhanced multi-detector row CT colonography--initial experience.

PURPOSE: To evaluate the accuracy of contrast material-enhanced multi-detector row computed tomographic (CT) colonography for preoperative staging of colorectal cancer. MATERIALS AND METHODS: Forty-one patients with colorectal carcinoma underwent preoperative contrast-enhanced multi-detector row CT colonography. Images were obtained in the arterial (start delay of 35 seconds) and portal venous (start delay of 70 seconds) phases. The arterial phase was focused on the suspected region of neoplasm, whereas the venous phase included the whole abdomen and pelvis. Two radiologists independently evaluated the depth of tumor invasion into the colorectal wall (T) and regional lymph node involvement (N) on transverse CT images alone and in combination with multiplanar reformations (MPRs). Disagreements were resolved by means of consensus. CT findings were compared with pathologic results, which served as the reference standard. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were assessed. Differences in accuracy for T and N staging were assessed by using the McNemar test. RESULTS: In T staging, overall accuracy was 73% when transverse images were evaluated alone and 83% when they were evaluated in combination with MPRs. This difference was not significant. N staging was associated with an overall accuracy of 59% with transverse images alone and 80% with combined transverse and MPR images (P <.01). CONCLUSION: Contrast-enhanced multi-detector row CT colonography is an accurate technique for preoperative local staging of colorectal tumors.

Adult↗
PubMed2005

Quality of reporting of diagnostic accuracy studies.

PURPOSE: To evaluate quality of reporting in diagnostic accuracy articles published in 2000 in journals with impact factor of at least 4 by using items of Standards for Reporting of Diagnostic Accuracy (STARD) statement published later in 2003. MATERIALS AND METHODS: English-language articles on primary diagnostic accuracy studies in 2000 were identified with validated search strategy in MEDLINE. Articles published in journals with impact factor of 4 or higher that regularly publish articles on diagnostic accuracy were selected. Two independent reviewers evaluated quality of reporting by using STARD statement, which consists of 25 items and encourages use of a flow diagram. Total STARD score for each article was calculated by summing number of reported items. Subgroup analyses were performed for study design (case-control or cohort study) by using Student t tests for continuous outcomes and chi(2) tests for dichotomous outcomes. RESULTS: Included were 124 articles published in 2000 in 12 journals: 33 case-control and 91 cohort studies. Only 41% of articles (51 of 124) reported on more than 50% of STARD items, while no articles reported on more than 80%. A flow chart was presented in two articles. Assessment of reporting on individual items of STARD statement revealed wide variation, with some items described in 11% of articles and others in 92%. Mean STARD score (0-25 points available) was 11.9 (range, 3.5-19.5). Mean difference in STARD score between cohort studies and case-control studies was 1.53 (95% confidence interval: 0.24, 2.82). CONCLUSION: Quality of reporting in diagnostic accuracy articles published in 2000 is less than optimal, even in journals with high impact factor. Authors, editors, and reviewers should pay more attention to reporting by checking STARD statement items and including a flow diagram to represent study design and patient flow.

Case-Control Studies↗
PubMed2006

Volumetric cartilage measurements of porcine knee at 1.5-T and 3.0-T MR imaging: evaluation of precision and accuracy.

PURPOSE: To compare the precision and accuracy of 3.0-T and 1.5-T magnetic resonance (MR) imaging in the quantification of cartilage volume by using direct volumetric measurements as a reference standard. MATERIALS AND METHODS: The local animal experimentation committee did not require its approval for this study. Porcine knees were obtained from an abattoir. These specimens were used to optimize imaging parameters regarding effective signal-to-noise ratio (SNRE) and contrast-to-noise ratio (CNRE) for a fat-saturated spoiled gradient-recalled acquisition in the steady state (SPGR) sequence, a water excitation SPGR sequence, and a fast spin-echo sequence at 3.0 T and a fat-saturated SPGR sequence at 1.5 T. By using the optimized sequences, 18 specimens were imaged in less than 6 minutes per sequence. A fivefold repetition of measurements of four specimens was performed for precision analysis. Cartilage was segmented by using semiautomatic software to calculate the volume. After imaging, the cartilage was scraped off and the volume was measured directly by using a saline-displacement method to calculate accuracy. Precision and accuracy errors were calculated as the root-mean-squares of the single errors per specimen. RESULTS: SNRE and CNRE values, respectively, were highest for the water excitation sequence at 3.0 T (1.81 sec(-1/2) and 1.27 sec(-1/2)), followed by the fat-saturated SPGR sequence (1.52 sec(-1/2) and 1.07 sec(-1/2)). The fast spin-echo sequence and the fat-saturated SPGR sequence at 1.5 T had lower SNR(E) (1.27 sec(-1/2) and 0.59 sec(-1/2), respectively). Accuracy error for MR-based volume calculation at the femur was 5.0%, 3.0%, 21%, and 16% for the water excitation, fat-saturated SPGR, and fast spin-echo sequences at 3.0 T and the fat-saturated SPGR sequence at 1.5 T, respectively. CONCLUSION: MR imaging at 3.0 T was shown in our study to better quantify cartilage volume. SNRE and CNRE were substantially improved, resulting in significantly higher accuracy in determining cartilage volume.

Animals↗
PubMed2006

Developmental dysplasia of the hip: quality of reporting of diagnostic accuracy for US.

PURPOSE: To systematically review the quality of diagnostic accuracy reporting in studies on the use of ultrasonography (US) for the diagnosis of developmental dysplasia of the hip (DDH). MATERIALS AND METHODS: A systematic review of the MEDLINE, EMBASE, DARE, and Cochrane Library databases was performed by using a validated search strategy. Two independent reviewers evaluated articles by using the Standards for Reporting of Diagnostic Accuracy (STARD) and Quality Assessment of Studies of Diagnostic Accuracy included in Systematic Reviews (QUADAS) statements. Items were reported individually for STARD and QUADAS because these instruments do not incorporate a summary score. A simple kappa statistic with 95% confidence intervals was used to measure the level of agreement between the two reviewers. RESULTS: Ten studies were included. In three studies, reliability was investigated, and in seven studies elements of both validity and reliability were investigated. In no study did the authors adequately report more than 40% of the STARD items. The quality of methods that were used in the studies was poor. Only one (14%) of seven studies provided information on more than 50% of the QUADAS items. All studies included a good description of image acquisition, but data analysis was imperfect and lacked estimates of diagnostic accuracy and precision. Authors tended to overinterpret their results. CONCLUSION: Overall, there was imperfect reporting of diagnostic accuracy in studies on the use of US for diagnosis of DDH.

Hip Dislocation, Congenital↗
PubMed1987

Accuracy of the respiratory inductive plethysmograph during loaded breathing.

Indirect methods of measuring ventilation, such as the respiratory inductive plethysmograph (RIP), operate on the assumption that the respiratory system possesses two degrees of freedom of motion: the rib cage and abdomen. Accurate measurements have been obtained in many patients with pulmonary disease who possess additional degrees of freedom. Since calibration and validation of the RIP was carried out during quiet breathing in these patients, the amount of asynchronous or paradoxic breathing was presumably similar during the calibration and validation runs. Conversely, accuracy might be lost if following the initial calibration procedure the magnitude of chest wall distortion increased during subsequent validation runs. We calibrated the RIP during quiet breathing and examined its accuracy while subsequently breathing against resistive loads that required the generation of 20-80% of the subject's maximum inspiratory mouth pressure (Pmmax). We compared the relative accuracy of three commonly employed calibration methods: isovolume technique, least-squares technique, and single position loop-area technique. Up to 60% of Pmmax, 89% of the RIP values with the least-squares technique were within +/- 10% of simultaneous spirometric (SP) measurements and 100% were within +/- 20% of SP, compared with 63 and 91%, respectively, for the loop-area technique and 19 and 54%, respectively, for the isovolume technique. At 70 and 80% of Pmmax accuracy deteriorated. Accuracy of respiratory timing was judged in terms of fractional inspiratory time (TI/TT).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2004

Detection of neuroblastoma cells in bone marrow and peripheral blood by different techniques: accuracy and relationship with clinical features of patients.

PURPOSE: Detection of metastatic tumor cells in bone marrow (BM) and peripheral blood (PB) of children with neuroblastoma is crucial for prognosis and planning of therapy. Aims of this large descriptive repeated survey were to evaluate the diagnostic accuracy of different techniques in diagnostic samples obtained at several disease course time points and to correlate positive results with patient clinical features and outcome. EXPERIMENTAL DESIGN: BM aspirates, trephine biopsies, PB, and peripheral blood stem cell (PBSC) samples from Italian children with neuroblastoma were analyzed by morphological and histologic techniques, as well as by immunocytochemistry (IC) for disialoganglioside GD(2) and reverse transcription-PCRs (RT-PCRs) for tyrosine hydroxylase (TH) and pgp9.5 genes. The diagnostic odd ratio (DOR) was used to measure the accuracy of the different techniques. RESULTS: A total of 2,247 evaluations were done on 561 BM, 265 PB, and 69 PBSC samples from 247 patients. IC showed the best accuracy. Whereas TH RT-PCR accuracy was satisfactory, that of pgp9.5 was very low. Positive results obtained by IC in BM and PB samples at diagnosis from stage 1, 2, and 3 patients correlated with unfavourable outcome. No correlation was found between positive results obtained by IC or TH RT-PCR in BM, PB, and PBSC samples from stage 4 patients and their outcome. CONCLUSIONS: Because of its elevated diagnostic accuracy, IC may represent a useful adjunct to conventional morphological techniques, especially in view of its potential prognostic role in patients with localized disease. Longitudinal multicenter studies are warranted to definitely establish the clinical usefulness of TH RT-PCR.

Adolescent↗
PubMed2001

Diagnostic accuracy of percent free prostate-specific antigen in prostatic pathology and its usefulness in monitoring prostatic cancer patients.

INTRODUCTION: The aim of our study was to evaluate the clinical usefulness of percent free prostate-specific antigen (PSA) [ratio of free PSA (fPSA) to total PSA (tPSA); f/tPSA] in prostatic pathology and its usefulness in monitoring prostatic cancer patients. PATIENTS AND METHODS: Our prospective study was carried out on 470 consecutive male patients referred to our outpatient urological clinic for observation. We looked for relationships between tPSA, fPSA and percent free PSA and the patient's age, prostatic volume and histologic diagnosis as assessed by prostatic biopsies or surgical specimens (benign prostatic hypertrophy, carcinoma, hypertrophy with inflammation). In all cases, we calculated the specificity, sensitivity and diagnostic accuracy of percent free PSA in the diagnosis of prostatic diseases, using cutoff values ranging from 14 to 20%. In prostatic cancer patients, we considered the relationships between the various PSA molecular forms and staging, grading and follow-up values. We also evaluated the effects of hormonosuppressive therapy on the serum markers and noted for which tPSA value percent free PSA possessed the greatest diagnostic accuracy. RESULTS: While tPSA and fPSA values appeared to be correlated with patient age and prostatic volume, percent free PSA did not show a relationship with these parameters. The specificity, sensitivity and overall diagnostic accuracy were better assuming a 16% cutoff value for percent free PSA than with other cutoff values. Prostatic inflammation associated with benign hypertrophy can cause false positives in both tPSA and f/tPSA measurements, since 60% of these patients have an f/tPSA ratio below 16%. In diagnosing carcinoma, the diagnostic accuracy of percent free PSA is 100% when tPSA is between 2.5 and 4.0 ng/ml. Percent free PSA is not linked with staging in prostatic cancer, but it does appear to be related to the Gleason score. In patients receiving hormonosuppressive treatment, f/tPSA decreased significantly, and more so in patients with a higher Gleason score. In patients with disease in rapid progression, percent free PSA was lower than in patients in a stable condition. CONCLUSIONS: Based on our experience, 16% as the f/tPSA cutoff value for discriminating between benign and malignant pathologies is the best possible choice, as it provides the highest overall values of sensitivity, specificity and diagnostic accuracy (80, 61.5 and 84.5%, respectively) in the diagnosis of prostatic cancer. We believe that f/tPSA is not a definitive test for diagnosing prostatic cancer. Our observations on the behavior of percent free PSA in relation to prostatic carcinoma grading and staging and in the follow-up of carcinoma patients are interesting; however, further studies are needed to define the appropriate role of f/tPSA in patients with an established diagnosis of prostatic carcinoma and in the follow-up of patients with prostatic cancer.

Adult↗