Verification and Evaluation of a Passive Intensity Modulation Device for Bolus Conformal Therapy

Purpose: Bolus electron conformal therapy (BECT) provides effective radiation treatment for superficial cancers and other diseases close to the skin surface, but can have as great as a 30% planning target volume (PTV) dose heterogeneity due to scattering from the irregular proximal bolus surface. Intensity modulated (IM) BECT can improve PTV dose homogeneity, but is not currently available. This study fabricated patient-specific passive intensity modulators and validated their delivering planned dose distributions calculated by a modified pencil beam redefinition algorithm (PBRA). Methods: Two test-patterns and four patient-specific intensity modulators were designed, fabricated, and tested. Dose plans were generated using a research version of p.d (.decimal LLC, Sanford, FL), which contained an intensity modulation operator. Dose distributions under intensity modulators were measured using a water phantom and scanning diode. The PBRA was modified to calculate dose in the presence of island blocks (tungsten pins of varying diameters) embedded in a low-density, machinable foam contained within an electron cutout. Results: Dose under island blocks with axes parallel to central axis was greater than expected, believed due to electrons scattered from island blocks, hence island blocks with axes along rays diverging from the virtual source were recommended. The PBRA modeled machineable foam by shifting R90 0.1 cm shallower and scaling σθx by 1.5, calculating dose distributions under foam with an accuracy equal to that without foam; however, foam increased the penumbra indicating it beneficial to reduce its thickness (g×cm2). PBRA modifications for island blocks yielded doses within 3% of measurements for IRF \u3e75%, indicating the need to model scatter from and into island blocks for lower IRFs. For all four patient-specific intensity modulators, measured doses were within 3%/3mm of calculated doses for ≥99.5% of points having dose \u3e10%, proving the hypothesis. Conclusions: Results showed that patient intensity modulators could deliver dose (fluence) within 3%/3mm of that planned, indicating the PBRA was sufficiently accurate for the patients studied and that .decimal can fabricate intensity modulators capable of delivering planned dose distributions. Comparison of dose distributions measured with a dose matrix for additional patient plans having greater intensity modulation is needed to establish future QA criteria

IS IT REALLY MORE EXPENSIVE TO EAT HEALTHY FOODS? A CASE STUDY APPROACH

Many believe eating healthfully is too expensive and therefore opt for less expensive, lower quality foods. There are disputes between research groups and government as to whether nutrition policies should be adjusted. Federal programs have made strides in combating food insecurity through nutrition help and education programs, but many question if the amount of skills in food selection and preparation can compensate for limited incomes. Regardless, the low incomes\u27 diets are inadequate to meet nutritional needs and people are suffering the consequences. The purpose of this study was to determine the extent one can follow the USDA Food Guide Pyramid recommendations while only receiving SNAP benefits. Nine volunteers attempted to limit their food budget to $4.50 a day while maintaining MyPyramid recommendations. This study was a qualitative case study conducted in Southern Illinois in the spring of 2011. This study was descriptive, and the investigator gathered and analyzed the data

A critical review of the Online Safety Bill

The UK Parliament has tabled the Online Safety Bill to make the internet safer for users by requiring providers to regulate legal but harmful content on their platform. This paper critically assesses the draft legislation, surveying its rationale; its scope in terms of lawful and unlawful harms it intends to regulate; and the mechanisms through which it will be enforced. We argue that it requires further refinement if it is to protect free speech and innovation in the digital sphere. We propose four conclusions: further evidence is required to substantiate the necessity and proportionality of the Bill’s interventions; the Bill risks a democratic deficit by limiting the opportunity for parliamentary scrutiny; the duties of the bill may be too wide (in terms of burdening providers); and that enforcement of a Code of Practice will likely be insufficient

Are Grocery Store Tours Capturing the Right Audience? Characteristics of Students Who Volunteer to Receive a Grocery Store Tour

The goal of this research is to examine the demographics of students volunteering to receive a grocery store tour in order to assess if these students represent those most in need of the information. Dietetics students trained in giving grocery store tours through a Produce for Better Health grant provided store tours to college student volunteers, “tourists”. Tourists provided demographic and health behavior data which was analyzed using descriptive statistics, ANOVA, t-tests, and chi-square. Twenty-three student trainees gave tours to 49 student tourists. Most tourists were female (77.8%), of healthy Body Mass Index (BMI) (64.9%), and reported being healthy eaters (47.3%). Results indicated that tourists who were not healthy eaters, did not cook daily, and were not likely to increase produce intake after the tour had higher BMI’s. Few tourists were male, obese, or reported having less healthy eating habits. Future research should examine who is participating in store tours in order to optimize their impact on healthy eating and shopping habits by assuring recruitment of individuals most in need of the experience

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

Inositol 1,4,5-Trisphosphate Signalling Regulates the Avoidance Response to Nose Touch in Caenorhabditis elegans

When Caenorhabditis elegans encounters an unfavourable stimulus at its anterior, it responds by initiating an avoidance response, namely reversal of locomotion. The amphid neurons, ASHL and ASHR, are polymodal in function, with roles in the avoidance responses to high osmolarity, nose touch, and both volatile and non-volatile repellents. The mechanisms that underlie the ability of the ASH neurons to respond to such a wide range of stimuli are still unclear. We demonstrate that the inositol 1,4,5-trisphosphate receptor (IP3R), encoded by itr-1, functions in the reversal responses to nose touch and benzaldehyde, but not in other known ASH-mediated responses. We show that phospholipase Cβ (EGL-8) and phospholipase Cγ (PLC-3), which catalyse the production of IP3, both function upstream of ITR-1 in the response to nose touch. We use neuron-specific gene rescue and neuron-specific disruption of protein function to show that the site of ITR-1 function is the ASH neurons. By rescuing plc-3 and egl-8 in a neuron-specific manner, we show that both are acting in ASH. Imaging of nose touch–induced Ca2+ transients in ASH confirms these conclusions. In contrast, the response to benzaldehyde is independent of PLC function. Thus, we have identified distinct roles for the IP3R in two specific responses mediated by ASH

Treatment of Aspergillus fumigatus in Patients with Cystic Fibrosis: A Randomized, Placebo-Controlled Pilot Study

Many patients with cystic fibrosis develop persistent airway infection/colonization with Aspergillus fumigatus, however the impact of A. fumigatus on clinical outcomes remains unclear. The objective of this study was to determine whether treatment directed against Aspergillus fumigatus improves pulmonary function and clinical outcomes in patients with cystic fibrosis (CF).We performed a double-blind randomized placebo-controlled pilot clinical trial involving 35 patients with CF whose sputum cultures were chronically positive for A. fumigatus. Participants were centrally randomized to receive either oral itraconazole 5 mg/kg/d (N = 18) or placebo (N = 17) for 24 weeks. The primary outcome was the proportion of patients who experienced a respiratory exacerbation requiring intravenous antibiotics over the 24 week treatment period. Secondary outcomes included changes in FEV(1) and quality of life.Over the 24 week treatment period, 4 of 18 (22%) patients randomized to itraconazole experienced a respiratory exacerbation requiring intravenous antibiotics, compared to 5 of 16 (31%) placebo treated patients, P = 0.70. FEV(1) declined by 4.62% over 24 weeks in the patients randomized to itraconazole, compared to a 0.32% improvement in the placebo group (between group difference = -4.94%, 95% CI: -15.33 to 5.45, P = 0.34). Quality of life did not differ between the 2 treatment groups throughout the study. Therapeutic itraconazole blood levels were not achieved in 43% of patients randomized to itraconazole.We did not identify clinical benefit from itraconazole treatment for CF patients whose sputum was chronically colonized with A. fumigatus. Limitations of this pilot study were its small sample size, and failure to achieve therapeutic levels of itraconazole in many patients.ClinicalTrials.gov NCT00528190