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PubMed1999

Comparison of MRI with CT for the radiotherapy planning of prostate cancer: a feasibility study.

This feasibility study was performed to evaluate the suitability of MRI in defining appropriate pelvic radiotherapy treatment volumes, and to compare MRI sequences with CT for prostate cancer radiotherapy. Five patients with localized prostate cancer, imaged with four MRI sequences (spin echo (SE) T1, turbo SE (TSE) T2, high resolution TSE (HR) T2, and FLASH 3D (F3D)), compared with their corresponding CT planning scans. Segmentation ability of the following pelvic structures: prostatic apex (PA), prostate, rectum, bladder and seminal vesicles (SV), were evaluated by three independent observers. They used a five point grading scale based on the anatomical definition of the organ boundary, tissue contrast and multiplanar display. Results were averaged for the group and for each sequence. There was no significant interobserver variation in the assessed scores (p > 0.1). The average scores (+/- 1 SD) for all pelvic structures assessed by each imaging sequence were CT 1.3 +/- 0.6; SE T1 2.4 +/- 0.9; TSE T2 2.4 +/- 0.7; HR T2 2.2 +/- 0.7 and F3D 3.4 +/- 0.6. Compared with CT, the average MR score for each assessed pelvic structure was higher with a trend for all transaxial MR sequences to provide improved segmentation of the PA and rectum. The F3D sequence scored highest as it provided multiplanar views and avoided the problem of partial volume averaging. MRI, compared with CT, appears to provide improved definition of pelvic treatment volumes but further work is required to confirm this and to address the issues of MRI associated distortion and dosimetry before MRI can be used routinely for pelvic radiotherapy planning.

Aged↗
PubMed1986

A double-blind randomized controlled trial of the effect of a low- versus a middle-tar cigarette on respiratory symptoms--a feasibility study.

A feasibility study of a double-blind, randomized controlled trial of the effect of a low-versus a middle-tar cigarette on respiratory symptoms is described. A smoking questionnaire was sent to 19,366 households. Returned questionnaires (64%) yielded 604 middle-tar cigarette smokers aged 20-44 years; 342 replied to a health warning stating that they did not want to or had failed to stop smoking and of these 183 volunteered for the trial. Thus about every 100 households originally mailed yielded one volunteer. Of the volunteers, 95 men were randomly allocated to be sold a middle-tar cigarette and 88 to be sold a low-tar cigarette of identical appearance. The cigarettes were sold at three different reduced prices and the men were asked to smoke them for five weeks. There was a 22% drop-out and this was unrelated to type of cigarette smoked. A reduction in price of 20% was sufficient incentive for volunteers to participate. Cigarette butts were collected weekly or fortnightly and urine samples were collected initially and after three and five weeks. Compliance with the trial cigarettes was good. The excretion of nicotine metabolites, number of cigarettes smoked and average butt weight for men allocated the low-tar cigarette was not significantly different from that of those allocated the middle-tar cigarette. This suggested that the former compensated for the 37% reduction in the nicotine yield of their cigarette by taking more frequent or deeper puffs from their cigarette. The implications of these results for a large-scale, randomized controlled trial are discussed.

Adult↗
PubMed1998

Recruitment strategies in the women's health trial: feasibility study in minority populations. WHT:FSMP Investigators Group. Women's Health Trial:Feasibility Study in Minority Populations.

The Women's Health Trial:Feasibility Study in Minority Populations (WHT:FSMP) examined the feasibility of recruiting postmenopausal women from a broad range of racial and socioeconomic backgrounds into a primary prevention trial requiring marked reductions in dietary fat. Postmenopausal women aged 50-79 yr who had no history of cardiovascular disease or cancer and who consumed 36% or more total energy from fat qualified to participate. We randomized the women into dietary intervention (60%) or control (40%) groups; we aimed to randomize 750 women in 18 months in each of the three clinical centers. All centers achieved goals for randomization based on ethnicity, and two centers exceeded overall recruitment goals. The greatest source of randomized participants was mass mailing, followed by items in the media, referrals, and community outreach. Recruitment yields were generally similar for the ethnic groups but lower for less-educated participants. The experience of WHT:FSMP indicates that postmenopausal women from the African-American, Hispanic, and non-Hispanic white communities can be recruited into dietary intervention studies for the prevention of disease.

Black or African American↗
PubMed2003

Testing combined pharmacotherapies and behavioral interventions for alcohol dependence (the COMBINE study): a pilot feasibility study.

BACKGROUND: Medications (such as naltrexone and acamprosate) as well as behavioral therapies have been previously reported to be effective in the reduction of alcohol intake and to prevent relapse drinking. However, the efficacy of using several medications alone or together in combination with behavioral therapies has not been widely investigated. The purpose of this study was to evaluate the feasibility of this combined therapy approach to apply it to a larger scale multisite clinical trial. Outcome focused on recruitment, retention, adherence to study parameters and medication, physical complaints, and physiologic toxicity. METHODS: At 11 sites, 108 individuals with alcohol dependence were randomized in a double blind fashion to receive placebo, naltrexone, or acamprosate alone or in combination. In addition, some individuals were randomized to receive Medical Management (MM) provided by a health care practitioner alone or in combination with an enhanced behavioral intervention, Combined Behavioral Intervention (CBI), delivered by a trained therapist. A final group received CBI alone without pills. All participants were treated and assessed for a maximum of 16 weeks. RESULTS: The attendance at therapy and research visits, and medication adherence and tolerability were good with no statistical differences between the medication or behavioral intervention groups. Over 75% of participants completed the week-16, end of study, assessment and the average medication adherence (percent of total pills taken) was about 65%. The level and types of physical complaints were not unexpected and similar among the medication and placebo groups. There were no group differences in liver or kidney toxicity. Importantly, the combination of naltrexone and acamprosate did not present significantly more physical complaints than either alone. CONCLUSIONS: Sufficient numbers of alcohol dependent participants can be recruited and retained in a relatively sophisticated outpatient trial combining medications and behavioral interventions. Participant adherence to the trial protocol including medication regimens was at acceptable levels. Physical complaints and organ toxicity were within expected and acceptable levels. Based on these results a larger scale study utilizing these methodologies appears feasible.

Acamprosate↗
PubMed1983

[Health education in the prevention of ischemic heart disease in school children: feasibility study].

A feasibility study of health education was undertaken among the pupils of a primary school in order to: 1) investigate the level of participation of children and teachers to the program; 2) test the efficacy of the program itself; 3) determine whether the children can modify family's behavioral patterns of the family components. Seventy-two children, belonging to different socio-economic classes, were studied. Children were given a questionnaire at the beginning and the end of the programme course, which was held by previously trained teachers. The participation of children and teachers to the program was very satisfactory. On the contrary very low involvement of the parents was achieved. This experience emphasizes the difficulties that arise when interventions to modify adult people's life style are attempted. On the contrary, a standardized education program, to last a whole school year, could be a feasible useful and costless type of intervention not only for the primary prevention of coronary artery disease, but for any program of extensive health care.

Adolescent↗
PubMed1988

DSM-III in Ethiopia: a feasibility study.

A feasibility study of DSM-III on 40 Ethiopian visitors to a psychiatric outpatient clinic in Addis Ababa was carried out by a Dutch psychiatrist, with three of his Dutch colleagues. In spite of the highly idiosyncratic way in which Ethiopians present their complaints, the diagnostic criteria of DSM-III appeared to be useful to a certain extent. The outcome of an inter-rater reliability study was comparable with that of an American one. The results were congruent for the classes that are rather well-defined in the DSM-III, like the psychotic and affective disorders. This did not apply to the classes of the somatoform and factitious disorders. Possible reasons for this are discussed.

Adult↗
PubMed2005

Final results of the Lung Screening Study, a randomized feasibility study of spiral CT versus chest X-ray screening for lung cancer.

The Lung Screening Study (LSS) was a pilot study designed to assess the feasibility of conducting a large scale randomized controlled trial (RCT) of low radiation dose spiral computed tomography (LDCT) versus chest X-ray (CXR) for lung cancer screening. Baseline results of LSS have been previously reported. Here, we report on the findings at the year one screen and on the final results of the LSS study. A total of 1660 subjects were randomized to the LDCT arm and 1658 to the CXR arm. Compliance with screening declined from 96% at baseline to 86% at year one in the LDCT arm and declined from 93% at baseline to 80% at year one in the CXR arm. Positivity rates for the year one screen were 25.8% for LDCT and 8.7% for CXR. Cancer yield was significantly less at year one for LDCT, 0.57%, than at baseline, 1.9%; cancer yield for CXR increased from 0.45% at baseline to 0.68% at year one. Forty lung cancers in the LDCT arm and 20 in the CXR arm were diagnosed over the study period. Stage I cancers comprised 48% of cases in the LDCT arm and 40% in the CXR arm. A total of 16 stage III-IV cancers were observed in the LDCT arm versus nine in the CXR arm. The LSS has established the feasibility of a RCT comparing annual spiral CT to chest X-ray for lung cancer screening.

Aged↗
PubMed2005

Process analytical technology case study part I: feasibility studies for quantitative near-infrared method development.

This article is the first of a series of articles detailing the development of near-infrared (NIR) methods for solid-dosage form analysis. Experiments were conducted at the Duquesne University Center for Pharmaceutical Technology to qualify the capabilities of instrumentation and sample handling systems, evaluate the potential effect of one source of a process signature on calibration development, and compare the utility of reflection and transmission data collection methods. A database of 572 production-scale sample spectra was used to evaluate the interbatch spectral variability of samples produced under routine manufacturing conditions. A second database of 540 spectra from samples produced under various compression conditions was analyzed to determine the feasibility of pooling spectral data acquired from samples produced at diverse scales. Instrument qualification tests were performed, and appropriate limits for instrument performance were established. To evaluate the repeatability of the sample positioning system, multiple measurements of a single tablet were collected. With the application of appropriate spectral preprocessing techniques, sample repositioning error was found to be insignificant with respect to NIR analyses of product quality attributes. Sample shielding was demonstrated to be unnecessary for transmission analyses. A process signature was identified in the reflection data. Additional tests demonstrated that the process signature was largely orthogonal to spectral variation because of hardness. Principal component analysis of the compression sample set data demonstrated the potential for quantitative model development. For the data sets studied, reflection analysis was demonstrated to be more robust than transmission analysis.

Feasibility Studies↗
PubMed2004

Assessing occupational and domestic ELF magnetic field exposure in the uk adult brain tumour study: results of a feasibility study.

The feasibility of measuring exposure to extremely low frequency magnetic fields (ELF MF) in the UK Adult Brain Tumour Study (UKABTS) was examined. During the study, 81 individuals and 30 companies were approached with 79 individuals and 25 companies agreeing to participate. Exposure data were collected using EMDEX II dosemeters worn by the participants for 3-4 consecutive days. Data were collected over a total of 321 d, including non-occupational periods. The results showed occupational exposure to be the main determinant of overall exposure. Moderate to strong correlations were found between arithmetic mean exposure and all other metrics with the possible exception of maximum exposure. Significant differences in exposure were found between job categories with large variability in certain categories. Highest average exposures were found for security officers (arithmetic mean, AM: 0.78 micro T), secretaries (AM: 0.48 micro T) and dentists (AM: 0.42 micro T). Welding and working near high-voltage power lines were associated with elevated exposure. In summary, acceptably precise measures of ELF MF exposure are feasible at relatively moderate cost. The results were used to develop a protocol for data collection from subjects in the UKABTS.

Activities of Daily Living↗
PubMed1992

The Modification of Diet in Renal Disease Study: design, methods, and results from the feasibility study.

The Modification of Diet in Renal Disease (MDRD) Study is a multicenter clinical trial designed to assess acceptance, safety, and efficacy of restricted protein and phosphorus diets in patients with progressive renal disease. The Feasibility Study was designed to test procedures and recruitment strategies and to estimate sample size for the Full-Scale Trial. The Feasibility Study was not designed to compare rates of progression of renal disease among diet groups. Patients aged 18 to 75 years, with a glomerular filtration rate (GFR; measured by 125I-iothalamate clearance) between 7.5 and 80 mL/min/1.73 m2, and a previous progressive increase in serum creatinine, were eligible for enrollment. Compliance with prescribed dietary protein intake was calculated from urea nitrogen appearance (UNA). Nutritional status was monitored by anthropometry and serum proteins. Progression of renal disease was calculated as the rate of decline of GFR. Ninety-six patients met all of the eligibility requirements and were randomized to study diets. Follow-up was conducted for a mean duration of 14 months (range, 2 to 22 months). Although most patients did not achieve the prescribed protein intake, marked changes in intake were observed among patients assigned to the low-protein diets, and mean estimated protein intake differed significantly among diet groups. No patients became malnourished. Mean rates of decline in GFR were relatively slow, and variability among individuals was high. As expected, the number of patients enrolled was too small to determine if the rate of decline in GFR was significantly slower among patients assigned to the restricted protein and phosphorus diets. The rate of decline in GFR was significantly inversely correlated with long-term average mean arterial blood pressure (MAP), even among patients whose blood pressure was controlled to levels within the normal range. However, because patients were not randomly assigned blood pressure goals, it was not possible to determine whether a causal relationship exists. Based on the experience gained during the Feasibility Study, the design for the Full-Scale Study includes two studies of defined by patients' baseline levels of renal function. Within each study, patients will be assigned randomly to one of two diets, and within each diet group, to one of two levels of blood pressure control. Based on variability of rates of decline in GFR slopes observed during the Feasibility Study, 800 patients with follow-up periods of up to 4 years will be required for the Full-Scale Trial.

Adult↗
PubMed1997

Sequencing in nanofabricated arrays: a feasibility study.

The feasibility of using nanofabricated arrays as electrophoretic chambers for DNA sequencing is investigated. A specific array design, consisting of rows of closely spaced posts, separated by longer open spaces, is proposed. Molecules driven through the array by an electric field get hooked over obstacles at successive rows and their progress through the device is delayed as a consequences. The dependence of the delay time on molecular size is derived. Numerical evaluation indicates that a device of modest dimensions, operating at high fields, can rapidly resolve oligonucleotides containing several hundred bases.

DNA↗
PubMed2000

Contingent reinforcement of marijuana abstinence among individuals with serious mental illness: a feasibility study.

The feasibility of using monetary incentives to promote abstinence from marijuana use among individuals with serious mental illness was examined by using a within-subjects experimental design. Participants were 18 adults with schizophrenia or other serious mental illness who reported regular marijuana use. During 2 baseline conditions, participants received payment for submitting urine specimens independent of urinalysis results. During 3 incentive conditions, participants received varying amounts of money if urinalysis results were negative for recent marijuana use. The number of marijuana-negative specimens obtained was significantly greater during incentive than baseline conditions. These results provide evidence that marijuana use among at least some mentally ill individuals is sensitive to contingent reinforcement and support the potential feasibility of using contingency-management interventions to reduce substance abuse among the mentally ill.

Adult↗
PubMed2005

Tomographic bioluminescence imaging by use of a combined optical-PET (OPET) system: a computer simulation feasibility study.

The feasibility and limits in performing tomographic bioluminescence imaging with a combined optical-PET (OPET) system were explored by simulating its image formation process. A micro-MRI based virtual mouse phantom was assigned appropriate tissue optical properties to each of its segmented internal organs at wavelengths spanning the emission spectrum of the firefly luciferase at 37 degrees C. The TOAST finite-element code was employed to simulate the diffuse transport of photons emitted from bioluminescence sources in the mouse. OPET measurements were simulated for single-point, two-point and distributed bioluminescence sources located in different organs such as the liver, the kidneys and the gut. An expectation maximization code was employed to recover the intensity and location of these simulated sources. It was found that spectrally resolved measurements were necessary in order to perform tomographic bioluminescence imaging. The true location of emission sources could be recovered if the mouse background optical properties were known a priori. The assumption of a homogeneous optical property background proved inadequate for describing photon transport in optically heterogeneous tissues and led to inaccurate source localization in the reconstructed images. The simulation results pointed out specific methodological challenges that need to be addressed before a practical implementation of OPET-based bioluminescence tomography is achieved.

Computer Simulation↗
PubMed2003

MR imaging-guided focused ultrasound surgery of uterine leiomyomas: a feasibility study.

The feasibility and safety of magnetic resonance (MR) imaging-guided focused ultrasound surgery for uterine leiomyomas is reported. Sequential sonications were delivered to nine targets. Temperature-sensitive phase-difference MR imaging monitored the location of the focus and measured tissue temperature elevations, ensuring therapeutic dose. MR images and hysterectomy specimens were evaluated. Six leiomyomas received full therapeutic doses, and 98.5% of the sonications were visualized. MR thermometry was successful in all sonications and cases. Focal necrotic lesions were seen in all cases at MR, and five were pathologically confirmed. MR imaging-guided focused ultrasound causes thermocoagulation and necrosis in uterine leiomyomas and is feasible and safe, without serious consequences.

Adult↗
PubMed2003

Cardiac MR imaging with external respirator: synchronizing cardiac and respiratory motion--feasibility study.

The feasibility of electrocardiography (ECG)-synchronized respiration with an external cuirass-type respirator in cardiac magnetic resonance (MR) imaging was evaluated. Cardiac MR imaging was performed in 10 nonsedated healthy volunteers with an ECG-triggered external respirator that was modified for use in the MR environment. Coronary MR angiograms and multiphase gradient-echo cine images were acquired with one respiratory cycle performed per cardiac cycle. The technique was feasible and in this group of volunteers resulted in equivalent image quality but shorter acquisition times than those of conventional free-breathing and breath-holding techniques.

Adult↗
PubMed2004

Proteoglycan loss in human knee cartilage: quantitation with sodium MR imaging--feasibility study.

The feasibility of using sodium magnetic resonance (MR) imaging to detect proteoglycan loss in early-stage osteoarthritis is evaluated. Fixed charge density (FCD) maps were calculated from sodium MR imaging data collected in nine healthy volunteers and three individuals with symptoms of early-stage osteoarthritis by using a 4.0-T clinical MR imaging unit. Data from the healthy individuals revealed a mean FCD of -182 mmol/L +/- 9. Data from the symptomatic subjects revealed focal regions of decreased FCD, with mean values ranging from -108 to -144 mmol/L, indicating proteoglycan loss from the cartilage matrix. The data suggest that sodium MR imaging has potential for use as a quantitative diagnostic tool to measure changes in proteoglycan content in early-stage osteoarthritis.

Adult↗
PubMed2005

Catheter ultrasound phased-array transducers for thermal ablation: a feasibility study.

The feasibility of catheter single-element ultrasound transducers for cardiac ablation has been shown previously. We describe the design and testing of catheter-sized linear phased arrays transducers for ultrasound ablation. One array has 86 PZT-4 elements operating at 8 MHz and 5 MHz. The overall array size is 14.9 mm by 3.1 mm (10 Fr). The other array has 50 PZT-5 elements operating at 4 MHz and is 17 mm by 3.1 mm (10 Fr). In order to produce the intensity needed to create lesions in heart tissue, we modified a real-time, 3D scanner to produce 100 Vpp 256-cycle transmit pulses at a pulse repetition frequency of 14.1 kHz. This made it possible for the PZT-4 and PZT-5 transducers to produce ISPTA of 3.26 W/cm2 and 142 W/cm2, respectively. When driving the transducers at high duty factor, the transmit circuitry in the scanner was damaged. A mechanically-focused transducer with the same dimensions as the PZT-4 transducer was built. When transmitting continuously at 9 MHz, it produced an ISPTA of 29.3 W/cm2. This created a lesion 5 mm across and 5 mm deep in beef tissue while raising the focal temperature 23 degrees C. Ablation is within the capabilities of a catheter phased array transducer integrated into a diagnostic ultrasound scanner.

Catheter Ablation↗
PubMed1991

Piezoelectric shock wave lithotripsy of salivary gland stones: an in vitro feasibility study.

The feasibility of fragmentation of salivary stones by a new extracorporeal piezoelectric lithotripter was investigated. A total of 40 salivary stones were submitted to piezoelectric shock wave treatment. The diameter, weight, and volume of all the stones were determined prior to shock wave administration. After shock wave administration the chemical composition of the stones was investigated by X-ray diffractometry. Fragmentation was achieved in 35 out of the 40 (87.5%) stones. Twenty-five of the 40 (62.5%) stones were disintegrated "therapeutically adequate" (residual fragments less than 1.5 mm). A statistically significant correlation was not observed between the number of discharges required for disintegration and the diameter, weight, volume, or the chemical composition of the stones.

Feasibility Studies↗