Toxicity and Efficacy of Stereotactic Ablative Body Radiotherapy for Moderately Central Non-small Cell Lung Cancers Using 50 Gy in Five Fractions

AIMS

Stereotactic ablative body radiotherapy doses for peripheral lung lesions caused high toxicity when used for central non-small cell lung cancer (NSCLC). To determine a safe stereotactic ablative body radiotherapy dose for central tumours, the phase I/II Radiation Therapy Oncology Group RTOG 0813 trial used 50 Gy/five fractions as a baseline. From 2013, 50 Gy/five fractions was adopted at the Beatson West of Scotland Cancer Centre for inoperable early stage central NSCLC. We report our prospectively collected toxicity and efficacy data.

MATERIALS AND METHODS

Patient and treatment characteristics were obtained from electronic medical records. Tumours were classed as moderately central or ultra-central tumours using published definitions. Toxicity was assessed in a centralised follow-up clinic at 2 weeks, 6 weeks, 3 months, 6 months, 1 year and 2 years after treatment.

RESULTS

Fifty patients (31 women, 19 men, median age 75.1 years) were identified with T1-2N0M0 moderately central NSCLC; one patient had both an ultra-central and a moderately central tumour. Eighty-four per cent were medically unfit for surgery. Forty per cent had biopsy-proven NSCLC and 60% were diagnosed radiologically using 18-fluorodeoxyglucose positron emission tomography/computed tomography imaging. Fifty-six per cent of patients were Eastern Cooperative Oncology Group (ECOG) performance status 2 or worse. All patients received 50 Gy/five fractions on alternate days on schedule. Two patients died within 90 days of treatment, one from a chest infection, the other cause of death was unknown. There was one episode of early grade 3 oesophagitis and one grade 3 late dyspnoea. There was no grade 4 toxicity. Over a median follow-up of 25.2 months (range 1-70 months), there were 34 deaths: 18 unrelated to cancer and 16 due to cancer recurrence. The median overall survival was 27.0 months (95% confidence interval 20.6-35.9) and cancer-specific survival was 39.8 months (95% confidence interval 28.6, not reached).

CONCLUSION

This study has shown that 50 Gy/five fractions is a safe dose and fractionation for early stage inoperable moderately central NSCLC, with outcomes comparable with other series, even with patients with a poor performance status.

Production of a carrier-free standard 56Mn source for the NRC manganese salt bath

The National Research Council (NRC) of Canada's primary method for emission rate for radionuclide neutron sources utilizes a manganese salt bath which was last calibrated in the 1960s. At that time, an NRC RaBe neutron source was used to irradiate a solution of calcium permanganate to take advantage of the Szilard-Chalmers effect in producing the bulk ⁵⁶Mn material for standardization and calibration of the bath. When attempting to repeat this exercise, a small amount (~100 kBq) was produced. This amount was sufficient for the standardization process but did not yield enough material to calibrate the bath to a sufficient level of precision. Improvements upon the previous separation scheme adopted at NRC for the separation of the ⁵⁶Mn from the bulk irradiated material included the rinsing of the ⁵⁶Mn dioxide precipitate using a mixture of sulfuric acid and hydrogen peroxide. While these improvements made in the separation chemistry improved the yield of ⁵⁶Mn extraction from 60% to above 95% the maximum amount of activity was still quite low. Hence in March of 2018, the SLOWPOKE-2 Facility at the Royal Military College in Kingston, ON, was used to irradiate three vials of KMnO₄ in solution. An estimated 2 GBq was produced and sent to NRC, from which the extraction procedure recovered essentially all of the available ⁵⁶Mn. The ⁵⁶Mn was standardized using the 4πβ-γ anti-coincidence counting system and confirmed using the CIEMAT/NIST primary method. The resulting bulk material was certified with an uncertainty of 0.8% (k = 2). Minor quantities of ⁶⁵Zn, ^69mZn and ⁴²K were unexpectedly observed but were in minute quantities so as not to affect the results of the standardization or calibration. The standardized ⁵⁶Mn artifact was used to calibrate the Secondary Standard Ionizing Radiation Chamber System (SSIRCS) for a more rapid deployment of the calibrant in the future.

Personal and Neighborhood Attributes Associated with Cervical and Colorectal Cancer Screening in an Urban African American Population

Introduction

Assessing individual social determinants of health in primary care might be complemented by consideration of population attributes in patients’ neighborhoods. We studied associations between cervical and colorectal cancer screening and neighborhood attributes among an African American population in Philadelphia.

Methods

We abstracted demographic and cancer screening information from records of patients seen during 2006 at 3 federally qualified health centers and characterized patients’ census tracts of residence by using census, survey, and other data to define population metrics for poverty, racial segregation, educational attainment, social capital, neighborhood safety, and violent crime. We used generalized estimating equations to obtain adjusted relative risks of screening associated with individual and census tract attributes.

Results

Among 1,708 patients for whom colorectal cancer screening was recommended, screening was up to date for 41%, and among 4,995 women for whom cervical cancer screening was recommended, screening was up to date for 75%. After controlling for age, sex (for colorectal cancer screening), insurance coverage, and clinic site, people living in the most racially segregated neighborhoods were nearly 10% more likely than others to be unscreened for colorectal cancer. Other census tract population attributes were not associated with differences in screening levels for either cancer.

Conclusions

The association between lower rates of colorectal cancer screening and neighborhood racial segregation is consistent with known barriers to colonoscopy among African Americans combined with effects of segregation on health-related behaviors. Recognition of the association between segregation and lower colorectal cancer screening rates might be useful in informing and targeting community outreach to improve screening.

Neighborhood racial/ethnic segregation and BMI: A longitudinal analysis of the Multi-ethnic Study of Atherosclerosis

BACKGROUND

Current knowledge regarding the relationship between segregation and body weight is derived mainly from cross-sectional data. Longitudinal studies are needed to provide stronger causal inference.

METHODS

We use longitudinal data from the Multi-Ethnic Study of Atherosclerosis and apply an econometric fixed-effect strategy, which accounts for all time-invariant confounders, and compare results to conventional cross-sectional analyses. We examine the relationship between neighborhood-level racial/ethnic segregation, neighborhood poverty, and body mass index (BMI) separately for blacks, Hispanics, and whites. Segregation*gender interactions are included in all models. Neighborhood segregation was operationalized by the local Gi* statistic, which assesses the extent to which a neighborhood's racial/ethnic composition is under (Gi* statistic < 0) or over (Gi* statistic > 0) represented, given the composition in the broader (e.g., county) area. For black, Hispanic, and white stratified models, the Gi* statistic reflects the level of black, Hispanic, and white segregation, respectively. The Gi* statistic was scaled such that a unit change represents a 1.96 difference in the score.

RESULTS

Cross-sectional models indicated higher segregation to be negatively associated with BMI for white females and positively associated for Hispanic females. No association was found for black females or males in general. In contrast, fixed-effect models adjusting for neighborhood poverty, higher segregation was positively associated with BMI for black females (coeff = 0.25 kg/m2; 95% CI = [0.03, 0.46]; p-value = 0.03) but negatively associated for Hispanic females (coeff = -0.17 kg/m2; 95% CI = [-0.33, -0.01]; p-value  = 0.04) and Hispanic males (coeff = -0.20; 95% CI = [-0.39, -0.01]; p-value = 0.04). Further controls for socioeconomic factors fully explained the associations for Hispanics but not for black females.

CONCLUSIONS

Fixed-effect results suggest that segregation's impacts might not be universally harmful, with possible null or beneficial impacts, depending on race/ethnicity. The persistent associations after accounting for neighborhood poverty indicate that the segregation-BMI link may operate through different pathways other than neighborhood poverty.

Identifying neighborhood characteristics associated with diabetes and hypertension control in an urban African-American population using geo-linked electronic health records

For health care providers, information on community-level social determinants of health is most valuable when it is specific to the populations and health outcomes for which they are responsible. Diabetes and hypertension are highly prevalent conditions whose management requires an interplay of clinical treatment and behavioral modifications that may be sensitive to community conditions. We used geo-linked electronic health records from 2016 of African American patients of a network of federally qualified health centers in Philadelphia, PA to examine cross-sectional associations between characteristics of patients' residential neighborhoods and hypertension and diabetes control (n = 1061 and n = 2633, respectively). Hypertension and diabetes control were defined to align with the Health Resources and Services Administration (HRSA) Uniform Data System (UDS) reporting requirements for HRSA-funded health centers. We examined associations with nine measures of neighborhood socioeconomic status (poverty, education, deprivation index), social environment (violent crime, perceived safety and social capital, racial segregation), and built environment (land-use mix, intersection density). In demographics-adjusted log-binomial regression models accounting for neighborhood-level clustering, poor diabetes and hypertension control were more common in highly segregated neighborhoods (i.e., high proportion of African American residents relative to the mean for Philadelphia; prevalence ratio = 1.27 [1.02-1.57] for diabetes, 1.22 [1.12-1.33] for hypertension) and less common in more walkable neighborhoods (i.e., higher retail land use). Neighborhood deprivation was also weakly associated with poor hypertension control. An important consideration in making geographic information actionable for providers is understanding how specific community-level determinants affect the patient population beyond individual-level determinants.

Spatial accessibility to pediatric primary care in Philadelphia: an area-level cross sectional analysis

Background

Pediatric primary care visits are a foundational element in the health maintenance of children. Differential access may be a driver of racial inequities in health. We hypothesized that pediatric primary care accessibility would be lowest in neighborhoods with higher proportion of non-Hispanic Black residents.

Methods

Annual ratios (2008–2016) of providers to pediatric population were calculated by census tract in Philadelphia, Pennsylvania. Marginal logistic regression was used to estimate the independent association between neighborhood racial composition and access to pediatric primary care controlling for confounders.

Results

In general, low access to care was associated with greater neighborhood disadvantage (e.g., SES, % poverty, % public insurance). After controlling for neighborhood indicators of disadvantage, risk of being in the lowest quintile of access significantly increased as the percent of non-Hispanic Black residents increased.

Conclusion

A new measure of pediatric primary care accessibility demonstrates a persistent disparity in primary care access for predominantly non-Hispanic Black neighborhoods.

Measurement of selected androgens using liquid chromatography-tandem mass spectrometry in reproductive-age women with Type 1 diabetes

STUDY QUESTION

What information does androgen profiling using liquid chromatography tandem mass spectrometry (LC-MS/MS) provide in reproductive-age women with Type 1 diabetes (T1D)?

SUMMARY ANSWER

In T1D women, androstenedione proved most useful of the measured androgens in differentiating subgroups based on clinical phenotypes of hyperandrogenism (HA) and polycystic ovary syndrome (PCOS).

WHAT IS KNOWN ALREADY

The prevalence of HA and PCOS are increased in women with T1D. These observations are based on measurement of serum androgens using immunoassays, to-date no studies using LC-MS/MS have been reported in reproductive-age women with T1D.

STUDY DESIGN, SIZE, DURATION

This was a cross-sectional study with recruitment of three groups of reproductive-age women: women with T1D (n = 87), non-diabetic women with (N = 97) and without PCOS (N = 101).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Using LC-MS/MS, we aimed to characterize androgen profiles and PCOS status in women with T1D, and interpret findings in relation to cohorts of non-diabetic women with and without PCOS.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to non-diabetic women, dehydroepiandrosterone/dehydroepiandrosterone sulphate (DHEA/DHEAS) ratio was lower (P < 0.05) in women with T1D. Testosterone levels were greater in T1D women with clinical HA and anovulation compared to those without clinical HA and with regular cycles, while androstenedione levels were greater in T1D women with HA and anovulation compared to those with HA and regular cycles and also those without HA and with regular cycles (P < 0.05 for all). Compared to T1D women without PCOS, the 18% of T1D women who had PCOS were younger with lower BMI, an older age of menarche, and were more likely to have a positive family history of PCOS (P < 0.05 for all). Androgen levels did not differ between women with T1D and PCOS compared to BMI-matched non-diabetic women with PCOS, but androstenedione levels were greater in T1D women with PCOS compared to obese women with PCOS (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

Relatively small subgroups of patients were studied, reducing the power to detect small differences. Free testosterone levels were not measured using equilibrium dialysis, and were not calculated - commonly used formulae have not been validated in T1D.

WIDER IMPLICATIONS OF THE FINDINGS

Androstenedione is a sensitive biochemical marker of clinical hyperandrogenism and PCOS in T1D. T1D women with PCOS are leaner than those without PCOS but are more likely to have a family history of PCOS. Women with T1D and PCOS have a similar biochemical phenotype to lean non-diabetic women with PCOS but differ from obese women with PCOS. The mechanisms underlying PCOS in T1D and its clinical significance require further investigation.

STUDY FUNDING/COMPETING INTEREST(S)

The study was part-funded by the Meath Foundation. The authors have no competing interests.

Building a Data Platform for Cross-Country Urban Health Studies: the SALURBAL Study

Studies examining urban health and the environment must ensure comparability of measures across cities and countries. We describe a data platform and process that integrates health outcomes together with physical and social environment data to examine multilevel aspects of health across cities in 11 Latin American countries. We used two complementary sources to identify cities with ≥ 100,000 inhabitants as of 2010 in Argentina, Brazil, Chile, Colombia, Costa Rica, El Salvador, Guatemala, Mexico, Nicaragua, Panama, and Peru. We defined cities in three ways: administratively, quantitatively from satellite imagery, and based on country-defined metropolitan areas. In addition to "cities," we identified sub-city units and smaller neighborhoods within them using census hierarchies. Selected physical environment (e.g., urban form, air pollution and transport) and social environment (e.g., income, education, safety) data were compiled for cities, sub-city units, and neighborhoods whenever possible using a range of sources. Harmonized mortality and health survey data were linked to city and sub-city units. Finer georeferencing is underway. We identified 371 cities and 1436 sub-city units in the 11 countries. The median city population was 234,553 inhabitants (IQR 141,942; 500,398). The systematic organization of cities, the initial task of this platform, was accomplished and further ongoing developments include the harmonization of mortality and survey measures using available sources for between country comparisons. A range of physical and social environment indicators can be created using available data. The flexible multilevel data structure accommodates heterogeneity in the data available and allows for varied multilevel research questions related to the associations of physical and social environment variables with variability in health outcomes within and across cities. The creation of such data platforms holds great promise to support researching with greater granularity the field of urban health in Latin America as well as serving as a resource for the evaluation of policies oriented to improve the health and environmental sustainability of cities.