PURPOSE: This study was designed to identify the impact of uncertainty degree and uncertainty appraisal on cancer patients resilience. METHODS: A sample of 181 patients with cancer was recruited from a hospital in Incheon. Data were collected from May 20 to August 25, 2011. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient and multiple regression with the SPSS/WIN 12.0 program. RESULTS: The resilience for cancer patients showed a significant relationship with uncertainty degree and uncertainty appraisal. The significant factors influencing resilience were uncertainty degree and uncertainty appraisal, they explained 26.5% of the variance. CONCLUSION: Patients with cancer were adversely affected by uncertaint which led to a negative effect on resilience. The result suggests that intervention programs to reduce the level of uncertainty among patients could improve the resilience of cancer patients.
Humans ; Uncertainty

PURPOSE: This study was to explore the hope structures of the newly diagnosed cancer patients by examining the relationships between hope and the three concepts of 'Personal Spirit', 'Risk' and 'Authentic Caring' which composed the multidimensions of the Nekolaichuk and Bruera's hope model. METHODS: Data was collected via survey from 32 newly diagnosed cancer patients. The perceived meaning of life (PML) for 'personal spirit', perceived confidence in cure (PCC) for 'risk', and perceived family support (PFS) and perceived support from medical team (PSM) for 'authentic caring' were adapted from the definitions of the concepts in the model. Hope, PML, and PCC were measured with VAS. PFS and PSM were measured with Korean version of 'Cobb's family support scale', which was modified by Kang. Pearson correlation coefficients were used to identify the relationships among the concepts. RESULTS: The significant relationships were revealed between hope and PCC (p<.001), hope and PML (p<.001), PML and PCC (p<.001), PFS and PML (p=.030), and PSM and PML (p=.047). CONCLUSION: The newly diagnosed cancer patients experience hope in different ways. The cancer patients' hope immediate after diagnosis, however, is most likely to be experienced as seeking balance between uncertainty about cancer treatment and the meaning of life.
Humans ; Uncertainty

PURPOSE: We report the results of an external audit on the absorbed dose of radiotherapy beams independently performed by third parties. For this effort, we developed a method to measure the absorbed dose to water in an easy and convenient setup of solid water phantom. MATERIALS AND METHODS: In 2008, 12 radiotherapy centers voluntarily participated in the external auditing program and 47 beams of X-ray and electron were independently calibrated by the third party's American Association of Physicists in Medicine (AAPM) task group (TG)-51 protocol. Even though the AAPM TG-51 protocol recommended the use of water, water as a phantom has a few disadvantages, especially in a busy clinic. Instead, we used solid water phantom due to its reproducibility and convenience in terms of setup and transport. Dose conversion factors between solid water and water were determined for photon and electron beams of various energies by using a scaling method and experimental measurements. RESULTS: Most of the beams (74%) were within +/-2% of the deviation from the third party's protocol. However, two of 20 X-ray beams and three of 27 electron beams were out of the tolerance (+/-3%), including two beams with a >10% deviation. X-ray beams of higher than 6 MV had no conversion factors, while a 6 MV absorbed dose to a solid water phantom was 0.4% less than the dose to water. The electron dose conversion factors between the solid water phantom and water were determined: The higher the electron energy, the less is the conversion factor. The total uncertainty of the TG-51 protocol measurement using a solid water phantom was determined to be +/-1.5%. CONCLUSION: The developed method was successfully applied for the external auditing program, which could be evolved into a credential program of multi-institutional clinical trials. This dosimetry saved time for measuring doses as well as decreased the uncertainty of measurement possibly resulting from the reference setup in water.
Electrons ; Phenylpropionates ; Uncertainty ; Water

No abstract available.
Nursing Theory* ; Nursing* ; Uncertainty*

PURPOSE: This study was to understand and explain the adjustment of cancer patients receiving chemotherapy. Variables in this model were social support, uncertainty, resilience and coping. METHODS: The data were collected for approximately five months from May through to September 2006 with cancer patients receiving chemotherapy or cancer patients finished chemotherapy using self-administered questionnaires. Descriptive statistics program, Amos 5.0, was employed to verify the goodness of the hypothetic model and the hypotheses formulated in the study. RESULTS: The fitness of the finalized model turned out to be improved (chi2=332.644, df=70, GFI=.809, AGFI=.714, RMSEA=.138, AIC=402.644). Those variables made a 60.8% prediction of the patients adjustment. CONCLUSION: The hypothetic model presented in the study could serve to explain the adjustment of cancer patients receiving chemotherapy. Moreover, the use of the conceptual framework of the theory of planned nursing intervention would be very worthwhile as a strategy to boost the adjustment of cancer patients when receiving chemotherapy.
Humans ; Surveys and Questionnaires ; Uncertainty

PURPOSES: This study examined uncertainty and nursing need according to illness phases(phase I, II, III) in cancer patients, and investigated relationships between uncertainty and nursing need. METHODS: A cross-sectional descriptive study was conducted with a sample of 121 adult cancer patients treated in two hospitals. RESULTS: As for the total score, the uncertainty was not significantly different across the subgroups by illness phase. As for the subscale score, however, two sub-scales of the uncertainty were different across the subgroups. 'The unpredictability' was highest in illness phase I and II groups, while 'the lack of information' was highest in the illness phase III group. Nursing need as the total score was not significantly different across the subgroups by illness phase. However, all subscale scores of the nursing need were significantly different across the subgroups. Educational need was highest in the illness phase I group; physical and emotional needs were highest in the illness phase III group. Uncertainty and nursing need were not related to each other at any illness phase. CONCLUSION: The results suggest that nursing need and uncertainty may change across illness phases. Clinicians need to consider this pattern in caring for cancer patients.
Adult ; Humans ; Uncertainty

The CT number corresponds to electron density and its influence on dose calculation was studied. Five kinds of CT scanners were used to obtain images of electron density calibration phantom (Gammex RMI 467). Then the differences between CT numbers for each scanners were +/-2% in homogeneous medium and 9.5% in high density medium. In order to investigate the influence of CT number to dose calculation, patients' thoracic CT images were analyzed. The maximum dose difference was 0.48% for each organ. It acquired the phantom images inserted high density material in the water phantom. Comparing the doses calculated with CT images from each CT scanner, the maximum dose difference was 2.1% in 20 cm in depth. The exact density to CT number conversion according to CT scanner is required to minimize the uncertainty of dose depends on CT number. Especially the each hospital with various CT scanners has to discriminate CT numbers for each CT scanner. Moreover a periodic quality assurance is required for reproducibility of CT number.
Calibration ; Uncertainty ; Water

Recent radiotherapy dose planning system (RTPS) generally adapted the kernel beam using the convolution method for computation of tissue dose. To get a depth and profile dose in a given depth concerened a given photon beam, the energy spectrum was reconstructed from the attenuation dose of transmission of filter through iterative numerical analysis. The experiments were performed with 15 MV X rays (Oncor, Siemens) and ionization chamber (0.125 cc, PTW) for measurements of filter transmitted dose. The energy spectrum of 15 MV X-rays was determined from attenuated dose of lead filter transmission from 0.51 cm to 8.04 cm with energy interval 0.25 MeV. In the results, the peak flux revealed at 3.75 MeV and mean energy of 15 MV X rays was 4.639 MeV in this experiments. The results of transmitted dose of lead filter showed within 0.6% in average but maximum 2.5% discrepancy in a 5 cm thickness of lead filter. Since the tissue dose is highly depend on the its energy, the lateral dose are delivered from the lateral spread of energy fluence through flattening filter shape as tangent 0.075 and 0.125 which showed 4.211 MeV and 3.906 MeV. In this experiments, analyzed the energy spectrum has applied to obtain the percent depth dose of RTPS (XiO, Version 4.3.1, CMS). The generated percent depth dose from 6x6 cm2 of field to 30x30 cm2 showed very close to that of experimental measurement within 1% discrepancy in average. The computed dose profile were within 1% discrepancy to measurement in field size 10x10 cm, however, the large field sizes were obtained within 2% uncertainty. The resulting algorithm produced x-ray spectrum that match both quality and quantity with small discrepancy in this experiments.
Particle Accelerators ; Uncertainty

The Monte Carlo method cannot have been used for routine treatment planning because of heavy time consumption for the acceptable accuracy. Since calculation time is proportional to particle histories, we can save time by decreasing the number of histories. However, a small number of histories can cause serious uncertainties. In this study, we proposed Monte Carlo dose computation time and uncertainty reduction method using specially designed filters and adaptive denoising process. Proposed algorithm was applied to 6 MV photon and 21 MeV electron dose calculations in homogeneous and heterogeneous phantoms. Filtering time was negligible comparing to Monte Carlo simulation time. The accuracy was improved dramatically in all situations and the simulation of 1% to 10% number of histories of benchmark in photon and electron dose calculation showed the most beneficial result. The empirical reduction of necessary histories was about a factor of ten to fifty from the result.
Monte Carlo Method ; Uncertainty

This paper evaluates the uncertainty in the measurement of radiated disturbance by analyzing and calculating the components that influence the uncertainty. And the effectiveness of the uncertainty testing has been confirmed through the ability validation.
Radiometry ; methods ; Uncertainty