Associations of Cumulative Perceived Stress with Cardiovascular Risk Factors and Outcomes: Findings from The Dallas Heart Study.

Background: Data remain sparse regarding the impact of chronic stress on cardiovascular disease (CVD) risk factors and outcomes. Prior work has been limited by incomplete assessments of perceived stress and focus on single stress domains. We evaluated the association between a composite measure of perceived stress and CVD risk factors and outcomes. Methods: Participants from the Dallas Heart Study phase 2 (2007-2009) without prevalent CVD who completed questionnaire assessments of perceived stress were included (n=2685). Individual perceived stress subcomponents (generalized stress, psychosocial, financial, and neighborhood stress) were standardized and integrated into a single cumulative stress score (CSS) with equal weighting for each component. Associations between CSS and demographics, psychosocial variables and cardiac risk factors were assessed in univariable and multivariable analyses. Cox proportional hazards models were used to determine associations of the CSS with atherosclerotic CVD (ASCVD) and Global CVD (ASCVD, heart failure, and atrial fibrillation) after adjustment for demographics and traditional risk factors. Results: Median age of the study population was 48 years, 55% were female, 49% Black and 15% Hispanic/Latinx. CSS was higher among participants who were younger, female, Black or Hispanic, and those with lower income and educational attainment (p<.0001 for each). Higher CSS was associated with self-report of racial/ethnic discrimination, lack of health insurance and last medical contact > one year previously (p<.0001 for each). In multivariable regression models adjusting for age, gender, race/ethnicity, income and education, higher CSS associated with hypertension, smoking, and higher body mass index, waist circumference Hemoglobin A1C, hs-CRP and sedentary time (p< 0.01 for each). Over a median follow-up of 12.4 years, higher CSS associated with ASCVD (adjusted HR 1.22 per SD, 95% CI 1.01-1.47) and Global CVD (HR 1.20, 95% CI 1.03-1.40). No interactions were seen between CSS, demographic factors, and outcomes. Conclusion: Composite multidimensional assessments of perceived stress may help to identify individuals at risk for CVD who may be targeted for stress mitigation or enhanced prevention strategies. These approaches may be best focused on vulnerable populations, given the higher burden of stress in women, Black and Hispanic individuals, and those with lower income and education. WHAT IS NEW?: A novel measure of cumulative stress was created that integrates generalized, psychosocial, financial, and neighborhood perceived stress.Cumulative stress was higher among women, Black and Hispanic participants, younger individuals and persons with lower income and educational attainment and was associated with adverse health behaviors and increased burden of cardiovascular disease (CVD) risk factors.In a diverse cohort, higher cumulative stress associated with incident CVD after adjustment for demographics and traditional risk factors. No interactions were seen based on demographic factors. CLINICAL IMPLICATIONS: Although associations of chronic stress with CVD were similar across demographic subgroups, the higher burden of stress among younger individuals, women, Black and Hispanic participants, and those with lower SES suggests that CVD risk associated with higher stress affects marginalized groups disproportionately.Cumulative Stress is associated with modifiable risk factors and health behaviors. Future studies should explore targeting behavioral modification and risk factor reduction programs, as well as stress reduction strategies, to individuals with high cumulative stress.Additional research is needed to uncover mechanisms that underly the association between chronic stress and cardiovascular disease.

Methodological Comparison of Mapping the Expanded Prostate Cancer Index Composite to EuroQoL-5D-3L Using Cross-Sectional and Longitudinal Data: Secondary Analysis of NRG/RTOG 0415.

PURPOSE: To compare the predictive ability of mapping algorithms derived using cross-sectional and longitudinal data. METHODS: This methodological assessment used data from a randomized controlled noninferiority trial of patients with low-risk prostate cancer, conducted by NRG Oncology (ClinicalTrials.gov identifier: NCT00331773), which examined the efficacy of conventional schedule versus hypofractionated radiation therapy (three-dimensional conformal external beam radiation therapy/IMRT). Health-related quality-of-life data were collected using the Expanded Prostate Cancer Index Composite (EPIC), and health utilities were obtained using EuroQOL-5D-3L (EQ-5D) at baseline and 6, 12, 24, and 60 months postintervention. Mapping algorithms were estimated using ordinary least squares regression models through five-fold cross-validation in baseline cross-sectional data and combined longitudinal data from all assessment periods; random effects specifications were also estimated in longitudinal data. Predictive performance was compared using root mean square error. Longitudinal predictive ability of models obtained using baseline data was examined using mean absolute differences in the reported and predicted utilities. RESULTS: A total of 267 (and 199) patients in the estimation sample had complete EQ-5D and EPIC domain (and subdomain) data at baseline and at all subsequent assessments. Ordinary least squares models using combined data showed better predictive ability (lowest root mean square error) in the validation phase for algorithms with EPIC domain/subdomain data alone, whereas models using baseline data outperformed other specifications in the validation phase when patient covariates were also modeled. The mean absolute differences were lower for models using EPIC subdomain data compared with EPIC domain data and generally decreased as the time of assessment increased. CONCLUSION: Overall, mapping algorithms obtained using baseline cross-sectional data showed the best predictive performance. Furthermore, these models demonstrated satisfactory longitudinal predictive ability.

Mapping expanded prostate cancer index composite to EQ5D utilities to inform economic evaluations in prostate cancer: Secondary analysis of NRG/RTOG 0415.

PURPOSE: The Expanded Prostate Cancer Index Composite (EPIC) is the most commonly used patient reported outcome (PRO) tool in prostate cancer (PC) clinical trials, but health utilities associated with the different health states assessed with this tool are unknown, limiting our ability to perform cost-utility analyses. This study aimed to map EPIC tool to EuroQoL-5D-3L (EQ5D) to generate EQ5D health utilities. METHODS AND MATERIALS: This is a secondary analysis of a prospective, randomized non-inferiority clinical trial, conducted between 04/2006 and 12/2009 at cancer centers across the United States, Canada, and Switzerland. Eligible patients included men >18 years with a known diagnosis of low-risk PC. Patient HRQoL data were collected using EPIC and health utilities were obtained using EQ5D. Data were divided into an estimation sample (n = 765, 70%) and a validation sample (n = 327, 30%). The mapping algorithms that capture the relationship between the instruments were estimated using ordinary least squares (OLS), Tobit, and two-part models. Five-fold cross-validation (in-sample) was used to compare the predictive performance of the estimated models. Final models were selected based on root mean square error (RMSE). RESULTS: A total of 565 patients in the estimation sample had complete information on both EPIC and EQ5D questionnaires at baseline. Mean observed EQ5D utility was 0.90±0.13 (range: 0.28-1) with 55% of patients in full health. OLS models outperformed their counterpart Tobit and two-part models for all pre-determined model specifications. The best model fit was: "EQ5D utility = 0.248541 + 0.000748*(Urinary Function) + 0.001134*(Urinary Bother) + 0.000968*(Hormonal Function) + 0.004404*(Hormonal Bother)- 0.376487*(Zubrod) + 0.003562*(Urinary Function*Zubrod)"; RMSE was 0.10462. CONCLUSIONS: This is the first study to identify a comprehensive set of mapping algorithms to generate EQ5D utilities from EPIC domain/ sub-domain scores. The study results will help estimate quality-adjusted life-years in PC economic evaluations.

Tolerance doses for late adverse events after hypofractionated radiotherapy for prostate cancer on trial NRG Oncology/RTOG 0415.

PURPOSE/OBJECTIVE: Hypofractionated radiotherapy (HRT) regimens for prostate cancer are emerging, but tolerance doses for late adverse events are scarce. The purpose of this study is to define dose-volume predictors for late gastrointestinal and genitourinary (GI and GU) toxicities after HRT in the multi-center NRG Oncology/RTOG 0415 low-risk prostate cancer trial (N = 521). MATERIAL/METHODS: Treatment in the studied HRT arm was delivered as 70 Gy at 2.5 Gy/fraction with 3D-CRT/IMRT (N = 108/413). At a median follow-up of 5.9 years, the crude late ≥Grade 2 GI and GU toxicities were 19% and 29%, respectively. For modeling, the complete HRT cohort was randomly split into training and validation (70% and 30%; preserved toxicity rates). Within training, dose-response modeling was based on dose-volume cut-points (EQD2Gy; bladder/rectum: α/ß = 6 Gy/3Gy), age, acute ≥Grade 2 toxicity, and treatment technique using univariate and multivariate logistic regression on bootstrapping (UVA and MVA). Candidate predictors were determined at p ≤ 0.05, and the selected MVA models were explored on validation where model generalizability was judged if the area under the receiver-operating curve in validation (AUCvalidation) was within AUCtraining ±â€¯SD with p ≤ 0.05, and with an Hosmer-Lemeshow p-value (pHL) > 0.05. RESULTS: Three candidate predictors were suggested for late GI toxicity: the minimum dose to the hottest 5% rectal volume (D5%[Gy]), the absolute rectal volume <35 Gy, and acute GI toxicity (AUC = 0.59-0.63; p = 0.02-0.04). The two generalizable MVA models, i.e., D5%[Gy] with or without acute GI toxicity (AUCvalidation = 0.64, 0.65; p = 0.01, 0.03; pHL = 0.45-0.56), suggest that reducing late GI toxicity from 20% to 10% would require reducing D5%[Gy] from ≤65 Gy to ≤62 Gy (logistic function argument: 17+(0.24D5%[Gy])). Acute GU toxicity showed only a trend to predict late GU toxicity (AUCtraining = 0.57; p = 0.07). CONCLUSION: Late GI toxicity, following moderate HRT for low-risk prostate cancer, increases with higher doses to small rectal volumes. This work provides quantitative evidence that limiting small rectal dose 'hotspots' in clinical practice of such HRT regimens is likely to further reduce the associated rates of GI toxicity.

Dosimetric consequences of interobserver variability in delineating the organs at risk in gynecologic interstitial brachytherapy.

PURPOSE: To investigate the dosimetric variability associated with interobserver organ-at-risk delineation differences on computed tomography in patients undergoing gynecologic interstitial brachytherapy. METHODS AND MATERIALS: The rectum, bladder, and sigmoid of 14 patients treated with gynecologic interstitial brachytherapy were retrospectively contoured by 13 physicians. Geometric variability was calculated using κ statistics, conformity index (CIgen), and coefficient of variation (CV) of volumes contoured across physicians. Dosimetric variability of the single-fraction D0.1cc and D2cc was assessed through CV across physicians, and the standard deviation of the total EQD2 (equivalent dose in 2 Gy per fraction) brachytherapy dose (SD(TOT)) was calculated. RESULTS: The population mean ± 1 standard deviation of κ, CIgen, and volume CV were, respectively: 0.77 ± 0.06, 0.70 ± 0.08, and 20% ± 6% for bladder; 0.74 ± 06, 0.67 ± 0.08, and 20% ± 5% for rectum; and 0.33 ± 0.20, 0.26 ± 0.17, and 82% ± 42% for sigmoid. Dosimetric variability was as follows: for bladder, CV = 31% ± 19% (SD(TOT) = 72 ± 64 Gy) for D0.1cc and CV = 16% ± 10% (SD(TOT) = 9 ± 6 Gy) for D2cc; for rectum, CV = 11% ± 5% (SD(TOT) = 16 ± 17 Gy) for D0.1cc and CV = 7% ± 2% (SD(TOT) = 4 ± 3 Gy) for D2cc; for sigmoid, CV = 39% ± 28% (SD(TOT) = 12 ± 18 Gy) for D0.1cc and CV = 34% ± 19% (SD(TOT) = 4 ± 4 Gy) for D2cc. CONCLUSIONS: Delineation of bladder and rectum by 13 physicians demonstrated substantial geometric agreement and resulted in good dosimetric agreement for all dose-volume histogram parameters except bladder D0.1cc. Small delineation differences in high-dose regions by the posterior bladder wall may explain these results. The delineation of sigmoid showed fair geometric agreement. The higher dosimetric variability for sigmoid compared with rectum and bladder did not correlate with higher variability in the total brachytherapy dose but rather may be due to the sigmoid being positioned in low-dose regions in the cases analyzed in this study.

Using an expanded outcomes framework and continuing education evidence to improve facilitation of patient-centered medical home recognition and transformation.

BACKGROUND: The patient-centered medical home is a model for delivering primary care in the United States. Primary care clinicians and their staffs require assistance in understanding the innovation and in applying it to practice. PURPOSES: The purpose of this article is to describe and to critique a continuing education program that is relevant to, and will become more common in, primary care. METHODS: A multifaceted educational strategy prepared 20 primary care private practices to achieve National Committee for Quality Assurance Level 3 recognition as Patient-Centered Medical Homes. RESULTS: Eighteen (90%) practices submitted an application to the National Committee for Quality Assurance. On the first submission attempt, 13 of 18 (72%) achieved Level 3 recognition and 5 (28%) achieved Level 1 recognition. CONCLUSION: An interactive multifaceted educational strategy can be successful in preparing primary care practices for Patient-Centered Medical Homes recognition, but the strategy may not ensure transformation. Future educational activities should consider an expanded outcomes framework and the evidence of effective continuing education to be more successful with recognition and transformation.

The Path to Quality in Outpatient Practice: Meaningful Use, Patient-Centered Medical Homes, Financial Incentives, and Technical Assistance.

Adoption and meaningful use of electronic health records is considered an essential step to improve the quality of health care. The authors assessed whether a series of Connecticut primary care providers who achieved Stage I Meaningful Use of electronic health records used quality improvement strategies that are associated with improvements in care. Practice structural characteristics, quality improvement-related electronic health record processes, outcomes, and barriers were assessed in 14 primary care practices. Implementation of quality improvement-related electronic health record processes was variable and barriers were common. Only 4 practices used data consistently to assess their performance, and only 3 reported improvements in care. Practices that were patient-centered medical homes scored higher on all quality improvement domains and received financial rewards more commonly. These findings suggest that primary care quality may be improved by formal alignment of Meaningful Use and Patient-Centered Medical Home criteria and by ongoing technical assistance to practices.

Opportunities to improve colorectal and breast cancer screening in Connecticut.

Colorectal and breast cancer represent serious and common public-health problems in the United States. While effective screening tests exist for both types of cancer, Connecticut lacks a consistent source of data about screening rates to guide improvement efforts. Beginning in 2011, the Connecticut Department of Public Health commissioned Qualidigm, the state's Medicare Quality Improvement Organization, to conduct an analysis of the most recent fee-for-service Medicare claims data to determine screening rates for colorectal cancer (2000-2009) and breast cancer (2008-2009). This article highlights key findings of this analysis in order to increase awareness of opportunities for improvement in colorectal and breast cancer screening. The article also offers recommendations about next steps that primary care clinicians can consider to improve cancer screening among their patient populations.

A comprehensive evaluation of a diabetes quality improvement project in privately owned primary care practices that serve minority patients.

The authors conducted a diabetes quality improvement project in 5 privately owned primary care practices serving at least 25% minority patients. Interventions included group-specific and practice-specific training on an electronic patient registry, cultural competency practices and tools, and selected quality improvement strategies. The authors conducted a comprehensive evaluation involving quantitative and qualitative data to assess project impact. Although overall clinical performance did not improve over the 14- to 20-month project time frame, other practice structural characteristics and processes did show improvement: successful implementation of the registry and clinician reminders in all practices, institution of team care and patient reminders in 4 practices, and collection of patient race/ethnicity data in 4 practices. These results highlight the difficulty of bringing about clinical improvement in this subset of practices and also the importance of conducting comprehensive evaluations to fully understand and interpret multicomponent quality improvement projects.

Challenges in recruiting minority-serving private practice primary care physicians to a quality improvement project.

The objectives of this study were the following: (1) describe one organization's experience with recruiting minority-serving private practice primary care physicians to an ambulatory quality improvement (QI) project; (2) compare and contrast physicians who agreed to participate with those who declined; and (3) list incentives and barriers to participation. The authors identified eligible physicians by analyzing Medicare Part B claims data, a publicly available physician database, and office staff responses to telephone inquiries. The recruitment team had difficulty identifying, contacting, and recruiting eligible physicians. Solo practitioners and physicians who had lower scores on certain quality measures were more likely to participate. Barriers to participation were similar in all practices and included concerns about extra work, difficulty of change, and impact on office work flow. Commonly used incentives were offered but were not universally embraced. Additional work is required to refine the process of physician recruitment and to find more compelling incentives for QI.

The Equity and Quality (EQual) Health-Care Project: A Connecticut Health Foundation initiative with Qualidigm.

In response to the growing incidence and prevalence of diabetes, quality and disparity of care concerns, and the increasing diversity of the US and Connecticut's populations, the Connecticut Health Foundation funded Qualidigm to implement the Equity and Quality (EQual) Health-Care Project. Now in its second full year, the EQualHealth-CareProject is helping eight primary-care practices in Connecticut improve the equity and quality of diabetes care through technology, education, and quality improvement.

Defining the rectal dose constraint for permanent radioactive seed implantation of the prostate.

PURPOSE: This study was performed to define the rectal dose constraint that would predict late rectal bleeding requiring argon plasma coagulation (APC) following prostate brachy mono-therapy. METHODS AND MATERIALS: Between February 1999 and April 2002, 91 patients with low risk prostate cancer underwent permanent I(125) radioactive seed implantation without the use of supplemental external beam radiation or androgen suppression therapy. Patients received both CT and MRI scans 6 weeks postimplant for evaluation of dosimetry. The CT and MRI scans were fused. Rectal volumes were contoured on the T2 weighted MR images. For those patients requiring APC, the date on which a patient reported rectal bleeding was recorded. A Cox regression analysis was performed to assess whether there was a significant association between the rectal volume (continuous) exceeding 100 Gy time rectal bleeding. Comparisons of estimates of rectal bleeding requiring APC were made using a 2-sided log rank test. RESULTS: There was a significant association (hazard ratio = 5.6 [95% confidence interval: 1.3, 23.8]; P = 0.002) between the rectal volume exceeding 100 Gy and rectal bleeding requiring APC. After a median follow-up of 4.25 (1-6) years, no patient with less than a median value of 8 cc of rectum exceeding 100 Gy required APC, whereas 20% (P = 0.004) were estimated to require APC within 3 years following treatment. CONCLUSIONS: Keeping the rectal volume receiving more than 100 Gy below 8 cc will minimize the risk of rectal bleeding requiring APC following I(125) permanent prostate brachy mono-therapy.

Understanding patterns of change over time to improve mammography rates.

This retrospective cohort study determined trends and patterns of mammography rates during 5 years (1997-2001) among female Medicare beneficiaries ages 50 years and older in Connecticut to better understand changes in rates over time and to plan future interventions. Time series analysis and hierarchical Longitudinal logistic regression were used to assess changes over time. Mammography rates increased significantly during the 5-year period (p < .001). A cyclical pattern was observed for all age groups and counties, with dips and peaks in the spring and fall each year (average increase 8% per year), consistent with concentrated intervention activity at those times.

Magnetic resonance image-guided salvage brachytherapy after radiation in select men who initially presented with favorable-risk prostate cancer: a prospective phase 2 study.

BACKGROUND: The authors prospectively evaluated the late gastrointestinal (GI) and genitourinary (GU) toxicity and prostate-specific antigen (PSA) control of magnetic resonance imaging (MRI)-guided brachytherapy used as salvage for radiation therapy (RT) failure. METHODS: From October 2000 to October 2005, 25 men with a rising PSA level and biopsy-proven, intraprostatic cancer at least 2 years after initial RT (external beam in 13 men and brachytherapy in 12 men) who had favorable clinical features (Gleason score < or =7, PSA < 10 ng/mL, negative pelvic and bone imaging studies), received MRI-guided salvage brachytherapy to a minimum peripheral dose of 137 gray on a phase 1/2 protocol. Estimates of toxicity and cancer control were calculated using the Kaplan-Meier method. RESULTS: The median follow-up was 47 months. The 4-year estimate of grade 3 or 4 GI or GU toxicity was 30%, and 13% of patients required a colostomy and/or urostomy to repair a fistula. An interval < 4.5 years between RT courses was associated with both outcomes with a hazard ratio of 12 (95% confidence interval [95% CI], 1.4-100; P = .02) for grade 3 or 4 toxicity and 25 (95% CI, 1.1-529; P = .04) for colostomy and/or urostomy. PSA control (nadir +2 definition) was 70% at 4 years. CONCLUSIONS: The current results indicated that MRI-guided salvage brachytherapy in men who are selected based on presenting characteristics and post-failure PSA kinetics can achieve high PSA control rates, although complications requiring surgical intervention may occur in 10% to 15% of patients. Prospective randomized studies are needed to characterize the relative cancer control and toxicity after all forms of salvage local therapy.

Synovial cell sarcoma of the vulva: multimodality treatment incorporating preoperative external-beam radiation, hemivulvectomy, flap reconstruction, interstitial brachytherapy, and chemotherapy.

BACKGROUND: Vulvar synovial cell sarcomas are rare, with only four previously published cases in the literature. Traditionally, the primary management for these tumors has been surgery alone. CASE: We report a case of a large vulvar synovial cell sarcoma in a 50-year-old woman treated with comprehensive combined multimodality management, including preoperative intensity-modulated radiation therapy, radical hemivulvectomy, flap reconstruction, interstitial low-dose-rate brachytherapy boost, and adjuvant chemotherapy. CONCLUSION: Based on this case and the limited data in the literature, multimodality treatment of advanced soft tissue sarcoma of the vulva may optimize local control and minimize toxicity while preserving sexual function.

Profiling variations in outpatient care for Medicare beneficiaries in Connecticut.

Qualidigm, the Medicare Quality Improvement Organization for Connecticut, is reporting the rates of four outpatient services for Medicare beneficiaries on its website (www.qualidigm.org). These measures include screening for breast cancer (mammography) and chronic disease management for diabetes (HbAlc, eye exam and lipid profile). Maps of Connecticut illustrate the rates for Whites and Non-whites by Health Service Area. The maps highlight variation across small local areas and between Whites and Non-whites. By reporting these rates publicly, Qualidigm hopes to facilitate ongoing efforts by community organizations and health care providers to make improvements in care, especially for the underserved populations throughout the state.

A prospective evaluation of rectal bleeding after dose-escalated three-dimensional conformal radiation therapy using an intrarectal balloon for prostate gland localization and immobilization.

OBJECTIVES: To estimate the rates of rectal bleeding after dose-escalated three-dimensional conformal radiation therapy (3D-CRT) on a prospective, Phase II study in which a modified intrarectal balloon was used for prostate gland localization and immobilization. METHODS: The study cohort comprised 100 men with biopsy-proven adenocarcinoma of the prostate and at least one high-risk feature (prostate-specific antigen level greater than 10 ng/mL, Gleason score 7 or higher, or clinical or radiographic T3 disease). Treatment consisted of androgen suppression therapy and four-field 3D-CRT with an intrarectal balloon for the initial 15 treatments. Planning treatment volume dose was 75.6 Gy. The primary endpoint of time to grade 3 rectal bleeding was estimated with the Kaplan-Meier method for 57 men with a minimum follow-up of 1 year. RESULTS: For 57 men with a median (range) follow-up of 1.8 (1.0 to 3.3) years, the median (range) volume of rectum exceeding 70 Gy was 3.7 (0.6 to 14.7) cm3, and the 2-year estimate of grade 3 rectal bleeding rate was 10%. This rate was 100% as compared with 0 (P < 0.0001) for men who were taking warfarin (n = 3) or high-dose aspirin (n = 1) as compared with neither, respectively. All grade 3 rectal bleeding events were controlled with argon plasma coagulation. CONCLUSIONS: Dose-escalated 3D-CRT with an intrarectal balloon technique for prostate localization and immobilization produced no measurable grade 3 rectal bleeding unless the patient was taking anticoagulants.

Acute urinary retention after magnetic resonance image-guided prostate brachytherapy with and without neoadjuvant external beam radiotherapy.

OBJECTIVES: To evaluate the risk of acute urinary retention (AUR) and sequelae after urethra-sparing magnetic resonance imaging (MRI)-guided prostate brachytherapy. METHODS: Between 1997 and 2003, MRI-guided prostate brachytherapy was performed after external beam radiotherapy (n = 60) or as monotherapy (n = 188) following a diagnosis of low-risk prostate adenocarcinoma. The median prostate gland volume was 40 cm3 (range 16 to 184). Of the 248 patients, 88 (35%) had prostate gland volumes greater than 45 cm3. The median follow-up was 40 months. RESULTS: Of the 248 patients, 18 (7%) developed AUR. Of the 248 patients, 2% (3 of 160), 6% (3 of 49), 28% (8 of 29), and 40% (4 of 10) of patients experienced AUR if the prostate gland volume was less than 45, 45 to 60, 60 to 90, or greater than 90 cm(3), respectively (P <0.0001). Retention requiring intermittent self-catheterization resolved in one half of the patients by 2 weeks and had resolved in all patients by 6 weeks. At 1, 3, and 6 months after implantation, 100%, 57%, and 29% of patients who experienced AUR, respectively, used Flomax (P <0.0001). The mean Flomax dose used decreased from 0.9 mg at 1 month to 0.53 mg at 1 year. CONCLUSIONS: AUR after urethral-sparing MRI-guided prostate brachytherapy is volume dependent and is self-limited despite very large prostate gland volumes.

A comparative study of rectal dose histograms in prostate brachytherapy: some analytic and numerical results.

A cumulative dose histogram is the graph of an integral function integrated over a domain VCR3 and is dubbed the dose-volume histogram (DVH), the dose-surface histogram (DSH) or the dose-wall histogram (DWH), depending on the dimension and structure of the region V. This paper presents a comparative study of the three rectal dose histograms for sixty patients as well as for a cylindrical model of the rectum; in particular, the DSH and DVH for the cylindrical model with one point source are computed analytically in terms of elliptic integrals. The difference among the three relative dose histograms, averaged over the sixty patients, is less than 5%, whereas that between DVH and DWH for various wall-thickness can be as large as 3-12 cm3 in the range 60-100 Gy. The paper also contains an error analysis using two simple models of the rectum, for which the true DSH and DWH can be computed via numerical integration, to evaluate the effect of digitization. The digitized computation agrees quite well with the pre-digitization numerical integration, within 1% or 0.2 cm3, because of the low dose-gradient effect near the rectum in prostate brachytherapy.