PURPOSE During radiotherapy (RT) for prostate cancer (PCa), interfraction and intrafraction movements can lead to decreased target dose coverage and unnecessary over-exposure of organs at risk. New image-guided RT techniques accuracy allows planning target volume (PTV) margins reduction. We aim to assess the feasibility of a kilovoltage intrafraction monitoring (KIM) to track the prostate during RT. METHODS AND MATERIALS Between November 2017 and April 2018, 44 consecutive patients with PCa were included in an intrafraction prostate motion study using the Truebeam Auto Beam Hold® tracking system (Varian Medical Systems, United State) triggered by gold fiducials localization on kilovoltage (kV) imaging. A 5-mm PTV was considered. A significant gating event (SGE) was defined as the occurrence of an automatic beam interruption requiring patient repositioning following the detection of one fiducial outside a 5-mm target area around the marker during more than 45seconds. RESULTS Six patients could not benefit from the KIM because of technical issues (loss of one fiducial marker=1, hip prosthesis=4, morbid obesity causing table movements=1). The mean rate of SGE per patient was 14±19%, and the fraction average delivery time was increased by 146±86seconds. For a plan of 39 fractions of 2Gy, the additional radiation dose increased by 0.13±0.09Gy. The mean rates of SGE were 2% and 18% (P=0.002) in patients with planned fraction90seconds respectively, showing that duration of the session strongly interfered with prostate intrafraction movements. No other significant clinical and technical parameter was correlated with the occurrence of SGE. CONCLUSION Automated intrafraction kV imaging can effectively perform autobeam holds due to intrafraction movement of the prostate in the large majority of patients. The additional radiation dose and delivery time are acceptable. This technique may be a cost-effective alternative to electromagnetic transponder guidance. BACKGROUND Health workforce planners in many high-income countries are considering policy strategies to retain home and overseas-trained health professionals. There is a lack of evidence on how hospitals can successfully integrate and retain skilled overseas professionals in relevant work roles. This study aimed to explore the integration and retention experiences of skilled American physician assistants/associates working in English hospitals. METHODS A qualitative study using semi-structured telephone interviews was undertaken in spring 2017 and spring 2018. Data were coded and analysed using thematic analysis. The study was framed within a theoretical model of role development. RESULTS Nineteen physician assistants/associates participated in interviews at timepoint one, and seventeen at timepoint two, across seven English hospitals. Four themes were identified in the integration and retention processes experienced by participants motivations and expectations, seeking role identity, acceptance and integration, and establishing a niche role. Supervising doctors appeared instrumental in creating opportunities through training and system adjustment that enabled development of niche roles; offering an effective match between participant skills and interests, and medical/surgical team or organisational needs. Whether or not they had a niche role influenced the decision of participants to remain or leave. CONCLUSION Integration approaches that maximise the value of the skilled health professional to the medical/surgical team and support retention, including development of optimum roles, require time and resources. PURPOSE Accommodative micro-fluctuations (AMF) are small dioptric changes during accommodation. The aim of this study was to evaluate and compare changes in AMF when wearing silicone hydrogel contact lenses of two different optical designs. METHODS A multi-centre, randomised, cross-over, non-dispensing study was conducted on 68 adapted contact lens wearers aged 25-35 years to compare AMF responses to a spherical and aspheric silicone hydrogel (comfilcon A) lens designs. A Righton Speedy "i" series Auto Refractometer in accommodation analyser mode was utilized before and after reading a standard text in font size 8 on an iPhone 5 for 20 min at a 25 cm viewing distance. Phone screen brightness was set by automatic adjustment mode and ambient illumination was controlled at all sites. RESULTS Mean ± SD AMF change from before to after the reading task was 2.25 ± 5.6 and 0.13 ± 5.7 (relative values) for the spherical and aspheric lens designs, respectively. The difference was statistically significant (P = 0.017, Paired t-test). CONCLUSIONS The smaller change in AMF when using an aspheric lens design suggests reduced ciliary muscle stress when reading print on a smart phone at a close distance for short periods (20 min). Contact lens wearers who frequently use digital devices and are experiencing eye strain may benefit from switching from a spherical design to one that incorporates aspheric optics. PURPOSE To estimate the prevalence of patient-reported midday fogging and to identify risk factors for midday fogging. METHOD A multicenter, cross-sectional study was conducted with an electronic survey that was distributed to scleral lens practitioners. The survey asked them to describe their most recently examined established scleral lens patient. Respondents provided data about patient-reported midday fogging, patient demographic characteristics, indication for lens wear, lens-wearing schedule, lens design, and care products. RESULTS Of the 248 survey respondents who indicated whether their patients had midday fogging, 64 (25.8 %) had patients who self-reported such issues. Midday fogging was not associated with demographic characteristics (age, sex, race/ethnicity), indications for scleral lens wear, mean lens diameter (P = .30), haptic design (P = .29), use of a daily cleaner (P = .12), disinfection/storage solution used (P = .71), or filling solution (P = .65). https://www.selleckchem.com/products/k-ras-g12c-inhibitor9.html Patients who reported midday fogging more commonly reported redness or irritation associated with scleral lens wear compared with those who did not experience midday fogging (P = .03). CONCLUSIONS Prevalence of midday fogging in this study was similar to previously reported rates. No specific lens design or care product was associated with patient-reported midday fogging. If inflammatory mediators are elevated in the postlens fluid reservoir of patients with midday fogging, as previously described, the redness or irritation associated with scleral lens wear suggests that ocular surface inflammation may be contributing to this phenomenon.
PURPOSE During radiotherapy (RT) for prostate cancer (PCa), interfraction and intrafraction movements can lead to decreased target dose coverage and unnecessary over-exposure of organs at risk. New image-guided RT techniques accuracy allows planning target volume (PTV) margins reduction. We aim to assess the feasibility of a kilovoltage intrafraction monitoring (KIM) to track the prostate during RT. METHODS AND MATERIALS Between November 2017 and April 2018, 44 consecutive patients with PCa were included in an intrafraction prostate motion study using the Truebeam Auto Beam Hold® tracking system (Varian Medical Systems, United State) triggered by gold fiducials localization on kilovoltage (kV) imaging. A 5-mm PTV was considered. A significant gating event (SGE) was defined as the occurrence of an automatic beam interruption requiring patient repositioning following the detection of one fiducial outside a 5-mm target area around the marker during more than 45seconds. RESULTS Six patients could not benefit from the KIM because of technical issues (loss of one fiducial marker=1, hip prosthesis=4, morbid obesity causing table movements=1). The mean rate of SGE per patient was 14±19%, and the fraction average delivery time was increased by 146±86seconds. For a plan of 39 fractions of 2Gy, the additional radiation dose increased by 0.13±0.09Gy. The mean rates of SGE were 2% and 18% (P=0.002) in patients with planned fraction90seconds respectively, showing that duration of the session strongly interfered with prostate intrafraction movements. No other significant clinical and technical parameter was correlated with the occurrence of SGE. CONCLUSION Automated intrafraction kV imaging can effectively perform autobeam holds due to intrafraction movement of the prostate in the large majority of patients. The additional radiation dose and delivery time are acceptable. This technique may be a cost-effective alternative to electromagnetic transponder guidance. BACKGROUND Health workforce planners in many high-income countries are considering policy strategies to retain home and overseas-trained health professionals. There is a lack of evidence on how hospitals can successfully integrate and retain skilled overseas professionals in relevant work roles. This study aimed to explore the integration and retention experiences of skilled American physician assistants/associates working in English hospitals. METHODS A qualitative study using semi-structured telephone interviews was undertaken in spring 2017 and spring 2018. Data were coded and analysed using thematic analysis. The study was framed within a theoretical model of role development. RESULTS Nineteen physician assistants/associates participated in interviews at timepoint one, and seventeen at timepoint two, across seven English hospitals. Four themes were identified in the integration and retention processes experienced by participants motivations and expectations, seeking role identity, acceptance and integration, and establishing a niche role. Supervising doctors appeared instrumental in creating opportunities through training and system adjustment that enabled development of niche roles; offering an effective match between participant skills and interests, and medical/surgical team or organisational needs. Whether or not they had a niche role influenced the decision of participants to remain or leave. CONCLUSION Integration approaches that maximise the value of the skilled health professional to the medical/surgical team and support retention, including development of optimum roles, require time and resources. PURPOSE Accommodative micro-fluctuations (AMF) are small dioptric changes during accommodation. The aim of this study was to evaluate and compare changes in AMF when wearing silicone hydrogel contact lenses of two different optical designs. METHODS A multi-centre, randomised, cross-over, non-dispensing study was conducted on 68 adapted contact lens wearers aged 25-35 years to compare AMF responses to a spherical and aspheric silicone hydrogel (comfilcon A) lens designs. A Righton Speedy "i" series Auto Refractometer in accommodation analyser mode was utilized before and after reading a standard text in font size 8 on an iPhone 5 for 20 min at a 25 cm viewing distance. Phone screen brightness was set by automatic adjustment mode and ambient illumination was controlled at all sites. RESULTS Mean ± SD AMF change from before to after the reading task was 2.25 ± 5.6 and 0.13 ± 5.7 (relative values) for the spherical and aspheric lens designs, respectively. The difference was statistically significant (P = 0.017, Paired t-test). CONCLUSIONS The smaller change in AMF when using an aspheric lens design suggests reduced ciliary muscle stress when reading print on a smart phone at a close distance for short periods (20 min). Contact lens wearers who frequently use digital devices and are experiencing eye strain may benefit from switching from a spherical design to one that incorporates aspheric optics. PURPOSE To estimate the prevalence of patient-reported midday fogging and to identify risk factors for midday fogging. METHOD A multicenter, cross-sectional study was conducted with an electronic survey that was distributed to scleral lens practitioners. The survey asked them to describe their most recently examined established scleral lens patient. Respondents provided data about patient-reported midday fogging, patient demographic characteristics, indication for lens wear, lens-wearing schedule, lens design, and care products. RESULTS Of the 248 survey respondents who indicated whether their patients had midday fogging, 64 (25.8 %) had patients who self-reported such issues. Midday fogging was not associated with demographic characteristics (age, sex, race/ethnicity), indications for scleral lens wear, mean lens diameter (P = .30), haptic design (P = .29), use of a daily cleaner (P = .12), disinfection/storage solution used (P = .71), or filling solution (P = .65). https://www.selleckchem.com/products/k-ras-g12c-inhibitor9.html Patients who reported midday fogging more commonly reported redness or irritation associated with scleral lens wear compared with those who did not experience midday fogging (P = .03). CONCLUSIONS Prevalence of midday fogging in this study was similar to previously reported rates. No specific lens design or care product was associated with patient-reported midday fogging. If inflammatory mediators are elevated in the postlens fluid reservoir of patients with midday fogging, as previously described, the redness or irritation associated with scleral lens wear suggests that ocular surface inflammation may be contributing to this phenomenon.
0 Comments 0 Shares 48 Views 0 Reviews
Sponsored