Consistency in electronic portal imaging registration in prostate cancer radiation treatment verification

BACKGROUND: A protocol of electronic portal imaging (EPI) registration for the verification of radiation treatment fields has been implemented at our institution. A template is generated using the reference images, which is then registered with the EPI for treatment verification. This study examines interobserver consistency among trained radiation therapists in the registration and verification of external beam radiotherapy (EBRT) for patients with prostate cancer. MATERIALS AND METHODS: 20 consecutive patients with prostate cancer undergoing EBRT were analyzed. The EPIs from the initial 10 fractions were registered independently by 6 trained radiation therapist observers. For each fraction, an anterior-posterior (AP or PA) and left lateral (Lat) EPIs were generated and registered with the reference images. Two measures of displacement for the AP EPI in the superior-inferior (SI) and right left (RL) directions and two measures of displacement for the Lat EPI in the AP and SI directions were prospectively recorded. A total of 2400 images and 4800 measures were analyzed. Means and standard deviations, as well as systematic and random errors were calculated for each observer. Differences between observers were compared using the chi-square test. Variance components analysis was used to evaluate how much variance is attributed to the observers. Time trends were estimated using repeated measures analysis. RESULTS: Inter-observer variation expressed as the standard deviation of the six observers' measurements within each image were 0.7, 1.0, 1.7 and 1.4 mm for APLR, APSI, LatAP and LatSI respectively. Variance components analysis showed that the variation attributed to the observers was small compared to variation due to the images. On repeated measure analysis, time trends were apparent only for the APLR and LatSI measurements. Their magnitude however was small. CONCLUSION: No clinically important systematic observer effect or time trends were identified in the registration of EPI by the radiation therapist observers in this study. These findings are useful in the documentation of consistency and reliability in the quality assurance of treatment verification of EBRT for prostate cancer

A national recruitment strategy for HIV-serodiscordant partners living in Canada for the Positive Plus One study: a mixed-methods study.

BACKGROUND: With the recent shift in focus to addressing HIV risk within relationships and couple-based interventions to prevent HIV transmission, successful recruitment of individuals involved in HIV-serodiscordant relationships is crucial. This paper evaluates methods used by the Positive Plus One (PP1) study to recruit and collect data on a diverse national sample of dyads and individuals involved in current or past HIV-serodiscordant relationships, discusses the strengths and limitations of the recruitment approach, and makes recommendations to inform the interpretation of study results and the design of future studies. METHODS: PP1 used a multi-pronged approach to recruit adults involved in a current or past HIV-serodiscordant relationship in Canada from 2016 to 2018 to complete a survey and an interview. Upon survey completion, index (first recruited) partners were invited to recruit their primary current HIV-serodiscordant partner. We investigated participant enrollment by recruitment source, participant-, relationship-, and dyad-level sociodemographic characteristics, missing data, and correlates of participation for individuals recruited by their partners. RESULTS: We recruited 613 participants (355 HIV-positive; 258 HIV-negative) across 10 Canadian provinces, including 153 complete dyads and 307 individuals who participated alone, and representing 460 HIV-serodiscordant relationships. Among those in current relationships, HIV-positive participants were more likely than HIV-negative participants to learn of the study through an ASO staff member (36% v. 20%, p < 0.001), ASO listserv/newsletter (12% v. 5%, p = 0.007), or physician/staff at a clinic (20% v. 11%, p = 0.006). HIV-negative participants involved in current relationships were more likely than HIV-positive participants to learn of the study through their partner (46% v. 8%, p < 0.001). Seventy-eight percent of index participants invited their primary HIV-serodiscordant partner to participate, and 40% were successful. Successful recruitment of primary partners was associated with longer relationship duration, higher relationship satisfaction, and a virally suppressed HIV-positive partner. CONCLUSIONS: Our findings provide important new information on and support the use of a multi-pronged approach to recruit HIV-positive and HIV-negative individuals involved in HIV-serodiscordant relationships in Canada. More creative strategies are needed to help index partners recruit their partner in relationships with lower satisfaction and shorter duration and further minimize the risk of "happy couple" bias

Disclosure of HIV-serodiscordant relationships and association with viral suppression: results from the Positive Plus One study.

BACKGROUND: Little is known about the effects of disclosure of HIV-serodiscordant relationships on clinical outcomes. We aimed to evaluate the effect of relationship disclosure on HIV viral suppression, and hypothesized that disclosure by HIV-positive and HIV-negative partners would be associated with viral suppression in the HIV-positive partner. METHODS: We conducted a Canadian national online and telephone-administered survey of HIV-positive and HIV-negative partners in serodiscordant relationships. The primary outcome was self-reported viral suppression. Multivariable analyses were undertaken using Firth logistic regression. RESULTS: We recruited 540 participants in current serodiscordant relationships (n = 228 HIV-negative; n = 312 HIV-positive). Similar proportions of HIV-positive and HIV-negative partners disclosed their relationship to healthcare professionals (82% v. 76%, p = 0.13). Among HIV-positive partners, disclosure of the relationship to healthcare professionals increased the odds of viral suppression (aOR = 4.7; CI: 2.13, 10.51) after adjusting for age, education, and relationship turmoil due to HIV. Increasing age (aOR = 1.28; 95% CI = 1.07, 1.55) and education (aOR = 2.43; 95% CI = 1.15, 5.26) were also associated with viral suppression. Among HIV-negative partners, relationship disclosure was not associated with viral suppression and HIV-negative heterosexual men were less likely to report that their HIV-positive partners were virally suppressed (aOR = 0.24; CI: 0.09, 0.61). CONCLUSIONS: Disclosure of HIV-serodiscordant status by HIV-positive participants to healthcare professionals was associated with increased odds of viral suppression. Similar effects were not evident among HIV-negative participants. Future work should explore factors that empower relationship disclosure and incorporate them into supportive services for HIV-serodiscordant relationships

Detection of Caries Around Resin-Modified Glass Ionomer and Compomer Restorations Using Four Different Modalities In Vitro

The aim of this study was to evaluate the ability of visual examination (International Caries Detection and Assessment System&mdash;ICDAS II), light-emitting diodes (LED) fluorescence (SPECTRA), laser fluorescence (DIAGNODent, DD), photothermal radiometry and modulated luminescence (PTR-LUM, The Canary System, CS) to detect natural decay beneath resin-modified glass ionomer (RMGIC) and compomer restorations in vitro. Twenty-seven extracted human molars and premolars, consisting of 2 control teeth, 10 visually healthy/sound and 15 teeth with natural cavitated lesions, were selected. For the carious teeth, caries was removed leaving some carious tissue on one wall of the preparation. For the sound teeth, 3 mm deep cavity preparations were made. All cavities were restored with RMGIC or compomer restorative materials. Sixty-eight sites (4 sites on sound unrestored teeth, 21 sound sites and 43 carious sites with restorations) were selected. CS and DD triplicate measurements were done at 2, 1.5, 0.5, and 0 mm away from the margin of the restoration (MOR). SPECTRA images were taken, and two dentists provided ICDAS II scoring for the restored surfaces. The SPECTRA data and images were inconclusive due to signal interference from the restorations. Visual examinations of the restored tooth surfaces were able to identify 5 of the 15 teeth with caries. In these situations, the teeth were ranked as having ICDAS II 1 or 2 rankings, but they could not identify the location of the caries or depth of the lesion. CS and DD were able to differentiate between sound and carious tissue at the MOR, but larger variation in measurement, and poorer accuracy, was observed for DD. It was concluded that the CS has the potential to detect secondary caries around RMGIC and compomer restorations more accurately than the other modalities used in this study