6 research outputs found
Planning and delivery of intensity modulated bolus electron conformal therapy
PURPOSE: Bolus electron conformal therapy (BECT) is a clinically useful, well-documented, and available technology. The addition of intensity modulation (IM) to BECT reduces volumes of high dose and dose spread in the planning target volume (PTV). This paper demonstrates new techniques for a process that should be suitable for planning and delivering IM-BECT using passive radiotherapy intensity modulation for electrons (PRIME) devices.
METHODS: The IM-BECT planning and delivery process is an addition to the BECT process that includes intensity modulator design, fabrication, and quality assurance. The intensity modulator (PRIME device) is a hexagonal matrix of small island blocks (tungsten pins of varying diameter) placed inside the patient beam-defining collimator (cutout). Its design process determines a desirable intensity-modulated electron beam during the planning process, then determines the island block configuration to deliver that intensity distribution (segmentation). The intensity modulator is fabricated and quality assurance performed at the factory (.decimal, LLC, Sanford, FL). Clinical quality assurance consists of measuring a fluence distribution in a plane perpendicular to the beam in a water or water-equivalent phantom. This IM-BECT process is described and demonstrated for two sites, postmastectomy chest wall and temple. Dose plans, intensity distributions, fabricated intensity modulators, and quality assurance results are presented.
RESULTS: IM-BECT plans showed improved D
CONCLUSION: These results demonstrated the feasibility of translating IM-BECT to the clinic using the techniques presented for treatment planning, intensity modulator design and fabrication, and quality assurance processes
Association of CpG island methylator phenotype and EREG/AREG methylation and expression in colorectal cancer
BACKGROUND: High EREG and AREG expression, and left-sided primary tumours are associated with superior efficacy of anti-epidermal growth factor receptor (EGFR) therapy in metastatic colorectal cancer (CRC), but a unifying explanation of these findings is lacking.
METHODS: RNA-seq, gene expression arrays, and DNA methylation profiling were completed on 179 CRC tumours. Results were validated using independent The Cancer Genome Atlas data sets. An independent cohort of 198 KRAS wild-type metastatic CRC tumours was tested for CpG island methylator phenotype (CIMP) status, and progression-free survival (PFS) with the first anti-EGFR regimen was retrospectively determined.
RESULTS: EREG and AREG expression was highly inversely correlated with methylation and was inversely associated with right-sided primary tumour, BRAF mutation, and CIMP-high status. Treatment of CRC cell lines with hypomethylating agents decreased methylation and increased expression of EREG. Inferior PFS with anti-EGFR therapy was associated with CIMP-high status, BRAF mutation, NRAS mutation, and right-sided primary tumour on univariate analysis. Among known BRAF/NRAS wild-type tumours, inferior PFS remained associated with CIMP-high status (median PFS 5.6 vs 9.0 mo, P=0.023).
CONCLUSIONS: EREG and AREG are strongly regulated by methylation, and their expression is associated with CIMP status and primary tumour site, which may explain the association of primary tumour site and EREG/AREG expression with anti-EGFR therapy efficacy
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Recommended from our members
Natural History of Sleep-disordered Breathing during Rapid Eye Movement Sleep. Relevance for Incident Cardiovascular Disease
Sleep-disordered breathing (SDB) occurring primarily during rapid eye movement (REM) sleep is a common clinical problem. The natural history of REM-related SDB and the associated cardiovascular sequelae of disease progression remain to be determined.
The objective of the current study was to describe the natural history of REM-related SDB, ascertain predictors of progression, and determine whether the evolution of REM-related SDB into non-REM (NREM) sleep is associated with incident cardiovascular events.
Participants from the Sleep Heart Health Study with a baseline NREM apnea-hypopnea index (NREM-AHI) of <5 events/h and data from a follow-up sleep study along with information on incident cardiovascular disease were included in the study. Bivariate logistic regression was used to jointly model the predictors of disease progression based on the presence or absence of SDB during NREM and REM sleep using a cut-point of 5 events/h. Explanatory variables such as age, race, body mass index (BMI), change in BMI, and baseline REM-AHI were considered. Proportional hazards regression was then used to establish whether the development of SDB during NREM sleep was associated with incident cardiovascular disease.
The majority of the 1,908 participants included in the study did not develop SDB during NREM sleep. The likelihood of progression of SDB into NREM sleep did increase with higher baseline REM-AHI. BMI and an increase in BMI predicted progression of SDB in both NREM and REM sleep in men but not in women. There was a strong interdependence between developing a NREM-AHI of ≥5 events/h and worsening REM-AHI at follow-up with odds ratios of 6.01 and 4.47, in women and men, respectively. Moreover, the relative risk for incident cardiovascular events among those who developed a NREM-AHI of ≥5 events/h at the follow-up visit was elevated only in women with REM-related SDB at baseline.
SDB during REM sleep is a relatively stable condition and does not progress in the majority of individuals. Progression of SDB into NREM sleep is associated with sex, weight, and age. SDB during REM and NREM sleep tends to develop concurrently. Finally, the development of SDB during NREM sleep is associated with incident cardiovascular events, but only in women with REM-related SDB at baseline
Association of CpG island methylator phenotype and EREG/AREG methylation and expression in colorectal cancer
BACKGROUND: High EREG and AREG expression, and left-sided primary tumours are associated with superior efficacy of anti-epidermal growth factor receptor (EGFR) therapy in metastatic colorectal cancer (CRC), but a unifying explanation of these findings is lacking. METHODS: RNA-seq, gene expression arrays, and DNA methylation profiling were completed on 179 CRC tumours. Results were validated using independent The Cancer Genome Atlas data sets. An independent cohort of 198 KRAS wild-type metastatic CRC tumours was tested for CpG island methylator phenotype (CIMP) status, and progression-free survival (PFS) with the first anti-EGFR regimen was retrospectively determined. RESULTS: EREG and AREG expression was highly inversely correlated with methylation and was inversely associated with right-sided primary tumour, BRAF mutation, and CIMP-high status. Treatment of CRC cell lines with hypomethylating agents decreased methylation and increased expression of EREG. Inferior PFS with anti-EGFR therapy was associated with CIMP-high status, BRAF mutation, NRAS mutation, and right-sided primary tumour on univariate analysis. Among known BRAF/NRAS wild-type tumours, inferior PFS remained associated with CIMP-high status (median PFS 5.6 vs 9.0 mo, P=0.023). CONCLUSIONS: EREG and AREG are strongly regulated by methylation, and their expression is associated with CIMP status and primary tumour site, which may explain the association of primary tumour site and EREG/AREG expression with anti-EGFR therapy efficacy
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4 m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5 m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 yr, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit