bluuebunny/crossref_metadata_2025_split huggingface dataset:
A device for precision positioning and alignment of room lasers to diminish their contribution to patient setup errors
Authors: Brezovich Ivan A. , Jordan Stephen 
Published: April 2008

This report presents an analysis of patient setup errors resulting from inaccurately positioned wall lasers. It suggests that laser beams should agree within 0.2 degree or better with the machine axes that they are delineating. For typical simulator and treatment rooms having wall‐to‐isocenter distances of 3 m, this requirement is satisfied when the beam‐emitting aperture is mounted within about 1.0 cm from the intersection of the respective machine axis with the wall. To achieve the required precision, we developed and clinically tested a simple, inexpensive tool, the Laser Placer (LP). The essential component of the LP is a cube with mirror surfaces that is aligned with the machine axes using built‐in spirit levels and the light field and crosshairs of the collimator. Wall, ceiling, and sagittal lasers are installed and aligned according to reflections of their beams by the cube, and reference lines provided by the LP. Measurements showed that, even in new accelerator installations performed by highly experienced technicians, wall lasers are often mounted off target by more than 1.5 cm. Such inaccuracies can contribute systematic errors of 2 mm or more to the random setup errors attributable to interfraction movement in patient anatomy. To keep setup errors to a minimum, medical physicists should check beam orthogonality in addition to beam congruence at isocenter as recommended by the TG‐40 quality assurance protocol from the American Association of Physicists in Medicine.PACS number: 87.53.‐j
Measurement of craniocaudal catheter displacement between fractions in computed tomography–based high dose rate brachytherapy of prostate cancer
Authors: Kim Yongbok , Hsu I‐Chow J. , Pouliot Jean 
Published: April 2008

The objective of the present work was to measure the craniocaudal displacement of catheters occurring between consecutive fractions of transrectal ultrasound (TRUS)‐guided high dose rate (HDR) prostate brachytherapy. Ten consecutive patients were treated with 2 fractions of 9.5‐Gy TRUS‐guided HDR brachytherapy, with dental putty being used for the fixation of catheters. For each patient, a computed tomography (CT) scan with 3‐mm slice thickness was acquired before each of the 2 fractions. Two different references were used to measure the catheter displacement between fractions: the ischial bone as a bony marker (BM) and the center of two gold markers (COGM) implanted in the prostate. Catheter displacement was calculated by multiplying the thickness of the CT slice by the difference in number of CT slices between the reference slice and the slice containing the tip of a catheter. The average magnitude of caudal catheter displacement was 2.7 mm (range: to 13.5 mm) for the BM method and 5.4 mm (range: to 18.0 mm) for the COGM method. The measurement data obtained from the BM and COGM methods verified that prostate movement and catheter displacement both occurred independently between fractions. The most anterior and medial two catheters (catheter positions 8 and 12) had the greatest tendency to be displaced in the caudal direction because they were located at the most distant position from the fulcrum, making them susceptible to rotation of the dental putty in the lateral plane because of the movement of the patients’ legs between fractions. In conclusion, the combination of the BM and COGM methods can demonstrate prostate and catheter movement relative to the BM between fractions. Our technique found a pattern of catheter displacement. Based on that finding, further improvement of our results may be possible by modification of our current technique.PACS number: 87.53.Jw
Using an onboard kilovoltage imager to measure setup deviation in intensity‐modulated radiation therapy for head‐and‐neck patients
Authors: Mechalakos James G. , Hunt Margie A. , Lee Nancy Y. , Hong Linda X. , Ling C. Clifton , Amols Howard I. 
Published: April 2008

The purpose of the present study was to use a kilovoltage imaging device to measure interfractional and intrafractional setup deviations in patients with head‐and‐neck or brain cancers receiving intensity‐modulated radiotherapy (IMRT) treatment.Before and after IMRT treatment, approximately 3 times weekly, 7 patients were imaged using the Varian On‐Board Imager (OBI: Varian Medical Systems, Palo Alto, CA), a kilovoltage imaging device permanently mounted on the gantry of a Varian 21EX LINAC (Varian Medical Systems). Because of commissioning of the remote couch correction of the OBI during the study, online setup corrections were performed on 2 patients. For the other 5 patients, weekly corrections were made based on a sliding average of the measured data. From these data, we determined the interfractional setup deviation (defined as the shift from the original setup position suggested by the daily image), the residual error associated with the weekly correction protocol, and the intrafractional setup deviation, defined as the difference between the post‐treatment and pretreatment images. We also used our own image registration software to determine interfractional and intrafractional rotational deviations from the images based on the template‐matching method. In addition, we evaluated the influence of inter‐observer variation on our results, and whether the use of various registration techniques introduced differences. Finally, translational data were compared with rotational data to search for correlations.Translational setup errors from all data were , , and in the right–left (RL), anterior–posterior (AP), and superior–inferior (SI) directions respectively. Residual error for the 5 patients with a weekly correction protocol was (RL), (AP), and (SI). Intrafractional translation errors were small, amounting to , , and in the RL, AP, and SI directions respectively. In the sagittal and coronal views respectively, interfractional rotational errors were degrees and degrees, and intrafractional rotational errors were degrees and degrees. No significant correlation was seen between translational and rotational data.The OBI image data were used to study setup error in the head‐and‐neck patients. Nonzero systematic errors were seen in the interfractional translational and rotational data, but not in the intrafractional data, indicating that the mask is better at maintaining head position than at reproducing it.PACS numbers:87.53.Kn, 87.53.Oq
Development of an optimum photon beam model for head‐and‐neck intensity‐modulated radiotherapy
Authors: Webster Gareth J , Rowbottom Carl G , Mackay Ranald I 
Published: April 2008

Intensity‐modulated radiotherapy (IMRT) for complex sites such as tumors of the head and neck requires a level of accuracy in dose calculation beyond that currently used for conformal treatment planning. Recent advances in treatment planning systems have aimed to improve the dose calculation accuracy by improving the modeling of machine characteristics such as interleaf leakage, tongue and groove, and rounded multileaf collimator (MLC) leaf ends. What is uncertain is the extent to which these model parameters improve the agreement between dose calculation and measurements for IMRT treatments.We used Pinnacle version 7.4f (Philips Medical Systems, Andover, MA) to carry out optimization of additional photon‐beam model parameters for both an Elekta Precise (Elekta, Stockholm, Sweden) and a Varian (Varian Medical Systems, Palo Alto, CA) linear accelerator (LINAC). One additional parameter was added to the beam models in turn, and associated models were commissioned to investigate the dosimetric impact of each model parameter on 5 clinical head‐and‐neck IMRT plans. The magnitude and location of differences between the models was determined from gamma analysis of the calculated planar dose maps. A final model that incorporated all of the changes was then commissioned. For the Elekta Precise, the impact of all the changes was determined using a gamma analysis as compared with measured films.Cumulative differences of up to more than 3%/3 mm were observed when dose distributions with and without all of the model changes were compared. Individually, for both LINACs, the addition of modeling for the rounded MLC leaf ends caused the most dramatic change to the calculation of the dose distribution, generating a difference of 3%/3 mm in up to 5% of pixels for the 5 patient plans sampled. The effect of tongue‐and‐groove modeling was more significant for the Varian LINAC (at 1%/1 mm, mean of 25% of pixels as compared with 5% of pixels with the Elekta Precise LINAC). The combined changes to the Elekta model were found to improve agreement with measurement.Current commercially available treatment planning systems offer accuracy sufficient for clinical implementation of head‐and‐neck IMRT. For this treatment site, the ability to accurately model the rounded MLC leaf ends has the greatest affect on the similarity of the calculated dose distribution to measurements. In addition, for the Varian LINAC, modeling of the tongue‐and‐groove effect was also advantageous.PACS numbers: 87.53.‐j, 87.53.Bn, 87.53.Tf
Learning a way through ethical problems: Swedish nurses’ and doctors’ experiences from one model of ethics rounds
Authors: Svantesson M , Löfmark R , Thorsén H , Kallenberg K , Ahlström G 
Published: April 2008

Objective:To evaluate one ethics rounds model by describing nurses’ and doctors’ experiences of the rounds.Methods:Philosopher-ethicist-led interprofessional team ethics rounds concerning dialysis patient care problems were applied at three Swedish hospitals. The philosophers were instructed to promote mutual understanding and stimulate ethical reflection, without giving any recommendations or solutions. Interviews with seven doctors and 11 nurses were conducted regarding their experiences from the rounds, which were then analysed using content analysis.Findings:The goal of the rounds was partly fulfilled. Participants described both positive and negative experiences. Good rounds included stimulation to broadened thinking, a sense of connecting, strengthened confidence to act, insight into moral responsibility and emotional relief. Negative experiences were associated with a sense of unconcern and alienation, as well as frustration with the lack of solutions and a sense of resignation that change is not possible. The findings suggest that the ethics rounds above all met the need of a forum for crossing over professional boundaries. The philosophers seemed to play an important role in structuring and stimulating reasoned arguments. The nurses’ expectation that solutions to the ethical problems would be sought despite explicit instructions to the contrary was conspicuous.Conclusion:When assisting healthcare professionals to learn a way through ethical problems in patient care, a balance should be found between ethical analyses, conflict resolution and problem solving. A model based on the findings is presented.
An assessment of the process of informed consent at the University Hospital of the West Indies
Authors: Barnett A T , Crandon I , Lindo J F , Gordon-Strachan G , Robinson D , Ranglin D 
Published: April 2008

Objective:To assess the adequacy of the process of informed consent for surgical patients at the University Hospital of the West Indies.Method:The study is a prospective, cross-sectional, descriptive study. 210 patients at the University Hospital of the West Indies were interviewed using a standardised investigator-administered questionnaire, developed by the authors, after obtaining witnessed, informed consent for participation in the study. Data were analysed using SPSS V.12 for Windows.Results:Of the patients, 39.4% were male. Of the surgical procedures, 68.6% were scheduled, 7.6% urgent and 23.8% emergency, 35.2% were minor and 64.8% major. Information imparted/received was acceptable in 40% of cases, good in 24% and inadequate (unacceptable) in 36% of cases. Almost all (97.6%) patients stated that they understood why an operation was planned and 93.3% thought that they had given informed consent. Most (95.2%) thought that they had free choice and made up their own mind. A quarter (25.2%) of all patients were told that it was mandatory for them to sign the form. There was a discussion of possible side effects and complications in 56.7% of patients.Conclusions:This study clearly indicates that surgical patients at the University Hospital of the West Indies feel that they have given informed consent. However, it also suggests that more information should be given to patients for consent to be truly informed.
The practicalities of terminally ill patients signing their own DNR orders—a study in Taiwan
Authors: Huang C-H , Hu W-Y , Chiu T-Y , Chen C-Y 
Published: April 2008

Objectives:To investigate the current situation of completing the informed consent for do-not-resuscitate (DNR) orders among the competent patients with terminal illness and the ethical dilemmas related to it.Participants:This study enrolled 152 competent patients with terminal cancer, who were involved in the initial consultations for hospice care.Analysis:Comparisons of means, analyses of variance, Student’s t test, χ2test and multiple logistic regression models.Results:After the consultations, 117 (77.0%) of the 152 patients provided informed consent for hospice care and DNR orders. These included 21 patients (17.9%) who signed the consent by themselves, and 96 (82.1%) whose consent sheet was signed only by family members. The reasons why patients were not involved in the discussions toward the consent (n = 82) included poor physical or psychological condition (44.9%), concerns of the consultant hospice team (37.2%), and the family’s refusal (28.2%). On a multivariate analysis, patients’ awareness of their poor prognosis (odds ratio = 4.07, 95% confidence interval = 2.05 to 8.07) and their understanding of hospice care (2.27, 1.33 to 3.89) were two independent factors (p<0.01) that influenced their participation in the discussions or their personal signature in the informed consent.Conclusion:The family-oriented culture in Asian countries may violate the principles of the Patient Self-Determination Act and the requirements of the Hospice Care Law in Taiwan, which inevitably poses an ethical dilemma. Earlier truth-telling and continuing education of the public by hospice care workers will be helpful in solving such ethical dilemmas.
The potential impact of decision role and patient age on end-of-life treatment decision making
Authors: Zikmund-Fisher B J , Lacey H P , Fagerlin A 
Published: April 2008

Background:Recent research demonstrates that people sometimes make different medical decisions for others than they would make for themselves. This finding is particularly relevant to end-of-life decisions, which are often made by surrogates and require a trade-off between prolonging life and maintaining quality of life. We examine the impact of decision role, patient age, decision maker age and multiple individual differences on these treatment decisions.Methods:Participants read a scenario about a terminally ill cancer patient faced with a choice between an aggressive chemotherapy regimen that will extend life by two years and palliative treatments to control discomfort for one remaining month. Participants were randomly assigned to one of three decision roles (patient, physician, or an abstract other) and the scenario randomly varied whether the patient was described as 25 or 65-years old.Results:When deciding for a 65-year old patient, approximately 60% of participants selected aggressive chemotherapy regardless of decision role. When deciding for a 25-year old patient, however, participants were more likely to select chemotherapy for a patient (physician role) or another person (abstract other) than for themselves (70%, 67%, and 59%, respectively). In addition, confidence that powerful others (eg, physicians) control one’s health, as well as respondents’ age and race, consistently predicted treatment choices.Conclusions:Patient age appears to influence medical decisions made for others but not those that we make for ourselves. These findings may help to explain the discord that often occurs when younger cancer patients refuse life-extending treatments.
The perceived role of Islam in immigrant Muslim medical practice within the USA: an exploratory qualitative study: Table 1
Authors: Padela A I , Shanawani H , Greenlaw J , Hamid H , Aktas M , Chin N 
Published: April 2008

Background:Islam and Muslims are underrepresented in the medical literature and the influence of physician’s cultural beliefs and religious values upon the clinical encounter has been understudied.Objective:To elicit the perceived influence of Islam upon the practice patterns of immigrant Muslim physicians in the USA.Design:Ten face-to-face, in-depth, semistructured interviews with Muslim physicians from various backgrounds and specialties trained outside the USA and practising within the the country. Data were analysed according to the conventions of qualitative research using a modified grounded-theory approach.Results:There were a variety of views on the role of Islam in medical practice. Several themes emerged from our interviews: (1) a trend to view Islam as enhancing virtuous professional behaviour; (2) the perception of Islam as influencing the scope of medical practice through setting boundaries on career choices, defining acceptable medical procedures and shaping social interactions with physician peers; (3) a perceived need for Islamic religious experts within Islamic medical ethical deliberation.Limitations:This is a pilot study intended to yield themes and hypotheses for further investigation and is not meant to fully characterise Muslim physicians at large.Conclusions:Immigrant Muslim physicians practising within the USA perceive Islam to play a variable role within their clinical practice, from influencing interpersonal relations and character development to affecting specialty choice and procedures performed. Areas of ethical challenges identified include catering to populations with lifestyles at odds with Islamic teachings, end-of-life care and maintaining a faith identity within the culture of medicine. Further study of the interplay between Islam and Muslim medical practice and the manner and degree to which Islamic values and law inform ethical decision-making is needed.
Patients’ preferences for receiving clinical information and participating in decision-making in Iran
Authors: Asghari F , Mirzazadeh A , Fotouhi A 
Published: April 2008

Introduction:This study, the first of its kind in Iran, was to assess Iranian patients’ preferences for receiving information and participating in decision-making and to evaluate their satisfaction with how medical information is given to them and with their participation in decision-making at present.Method and materials:299 of 312 eligible patients admitted to general internal medicine or surgery wards from May to December 2006 were interviewed according to a structured questionnaire. The questionnaire contained questions about patients’ preferences regarding four domains of information and their participation in decision-making. Patients’ responses were measured on a visual analogue scale graded from 1 to 10.Results:The mean (SD) score for desire to receive information was 8.88 out of 10 (1.5) and for participation in medical decision-making was 7.75 out of 10 (3). The desire to receive information was greater in women than men (9.0 (1.5) vs 7.8 (1.4), p = 0.025). It was also correlated with their education (r = 0.2, p = 0.001) and their estimation of the severity of their own disease (r = 0.13, p = 0.027). The score for preference to participate in decision-making was higher in women than in men (7.95 (2.8) and 7.0 (3.2), respectively; β = 0.8, p = 0.022) and was negatively correlated with education (r = −0.14, p = 0.015).Discussion:This study shows that Iranian patients are highly interested in receiving information about their condition and participating in clinical decision-making. No predictive variable for such attitudes was found; therefore, the only way for the physician to recognise patients’ desire is to ask them explicitly.
Interprofessional ethics rounds concerning dialysis patients: staff’s ethical reflections before and after rounds
Authors: Svantesson M , Anderzén-Carlsson A , Thorsén H , Kallenberg K , Ahlström G 
Published: April 2008

Objective:To evaluate whether ethics rounds stimulated ethical reflection.Methods:Philosopher-ethicist-led interprofessional team ethics rounds concerning dialysis patient care problems were applied at three Swedish hospitals. The philosophers were instructed to stimulate ethical reflection and promote mutual understanding between professions but not to offer solutions. Questionnaires directly before and after rounds were answered by 194 respondents. The analyses were primarily content analysis with Boyd’s framework but were also statistical in nature.Findings:Seventy-six per cent of the respondents reported a moderate to high rating regarding new insights on ethical problem identification, but the ethics rounds did not seem to stimulate the ethical reflection that the respondents had expected (p<0.001). Dominant new insights did not seem to fit into traditional normative ethics but were instead interpreted as hermeneutic ethics. This was illustrated in the extended perspective on the patient and increased awareness of relations to other professions. Regarding insights into how to solve ethical problems, the request for further interprofessional dialogue dominated both before and after rounds.Conclusion:The findings show the need for interprofessional reflective ethical practice but a balance between ethical reflection and problem solving is suggested if known patients are discussed. Further research is needed to explore the most effective leadership for reflective ethical practice.
Evaluation of two wild types of Pleurotus ostreatus (MCC07 and MCC20) isolated from nature for their ability to decolorize Benazol Black ZN textile dye in comparison to some commercial types of white rot fungi: Pleurotus ostreatus, Pleurotus djamor, and Pleurotus citrinopileatus
Authors: Kalmış Erbil , Azbar Nuri , Kalyoncu Fatih 
Published: April 2008

Biological decolorization of Benazol Black ZN, a reactive azo-type textile dyestuff, was comparatively studied using 3 different commercial-type white rot fungi strains ( Pleurotus ostreatus , Pleurotus cornucopiae var. citrinopileatus, Pleurotus djamor , and 2 wild types of P. ostreatus (MCC07 and MCC20) isolated from the nature. The initial dye concentrations in the medium were 500 and 1000 mg·L–1. All the organisms studied decolorized Benazol Black ZN to varying degrees. At low dye concentration, both commercial and wild type of P. ostreatus resulted in the best decolorization, conversely, wild-type P. ostreatus (MCC07) was found to be much more robust against increasing dye concentration and provided the best decolorization efficiency at high dye concentration.