Citations

Background Detection of small renal calculi has benefitted from recent advances in computed tomography (CT) scanner design. Information regarding observer performance when using state-of-the-art CT scanners for this application is needed. Purpose To assess observer performance and the impact of radiation dose for detection and size measurement of <4 mm renal stones using CT with integrated circuit detectors and iterative reconstruction. Material and Methods Twenty-nine <4 mm calcium oxalate stones were randomly placed in 20 porcine kidneys in an anthropomorphic phantom. Four radiologists used a workstation to record each calculus detection and size. JAFROC Figure of Merit (FOM), sensitivity, false positive detections, and calculus size were calculated. Results Mean calculus size was 2.2 ± 0.7 mm. The CTDI vol values corresponding to the automatic exposure control settings of 160, 80, 40, 25, and 10 Quality Reference mAs (QRM) were 15.2, 7.9, 4.2, 2.7, and 1.3 mGy, respectively. JAFROC FOM was ≥ 0.97 at ≥ 80 QRM, ≥ 0.89 at ≥ 25 QRM, and was inferior to routine dose (160 QRM) at 10 QRM (0.72, P < 0.05). Per-calculus sensitivity remained ≥ 85% for every reader at ≥ 25 QRM. Mean total false positive detections per reader were ≤ 3 at ≥ 80 QRM, but increased substantially for two readers ( ≥ 12) at ≤ 40 QRM. Measured calculus size significantly decreased at ≤ 25 QRM ( P ≤ 0.01). Conclusion Using low dose renal CT with iterative reconstruction and ≥ 25 QRM results in high sensitivity, but false positive detections increase for some readers at very low dose levels (≤ 40 QRM). At very low doses with iterative reconstruction, measured calculus size will artifactually decrease.

284 Background: MM is an uncommon cancer with annual incidence of only 27,000 cases in the US. Our study determined the extent to which the number of MM patients treated annually in a treatment facility affected all-cause mortality. Methods: We used the National Cancer Data Base (NCDB) to identify adult patients with MM diagnosed from 2003-2011. NCDB is sourced from over 1,500 Commission on Cancer-accredited cancer registries representing 70% of cancer cases in the US. We classified treatment facilities by quartiles based on facility volume (mean patients/year): Quartile 1 (Q1: < 3.6), Quartile 2 (Q2: 3.6-6.1), Quartile 3 (Q3: 6.1-10.3) and Quartile 4 (Q4: > 10.3). We used hot deck imputation to account for missing data, Cox regression to analyze the association between facility volume and time-to-death, and random intercepts to adjust for multiple patients per facility. Results: There were 94,722 MM patients cared for at 1,333 facilities. Most patients (73.5%) were diagnosed and treated in the same facility. The median age at diagnosis was 67 years and 54.7% were males. The median annual facility volume was 6.1 patients/year (IQR: 3.6-10.3; range: 0.2-109.9). The distribution of patients according to facility volume was Q1 (5.2%), Q2 (12.6%), Q3 (21.9%) and Q4 (60.3%). The unadjusted median overall survival by facility volume was: Q1: 26.9 months, Q2: 29.1 months, Q3: 31.9 months and Q4: 49.1 months. After multivariable analysis adjusting for demographic (sex, age, race, ethnicity), socioeconomic (income, education, insurance type), geographic (area of residence, treatment facility location), co-morbidity (Charlson-Deyo score), and disease-specific (year of diagnosis) factors, we show that facility volume remains an independent predictor of all-cause mortality. Compared to patients treated at Q4 facilities, patients treated at lower quartile facilities had a higher risk of death (Q3 HR: 1.16 [95% CI, 1.12-1.20]; Q2: 1.21 [1.17-1.26]; Q1: 1.27 [1.22-1.34]). We observed an inverse volume-outcome relationship up to an annual facility volume of approximately 60 patients. Conclusions: MM patients treated at higher volume facilities had lower risk of mortality compared to those treated at lower volume facilities.

Purpose To determine the association between the number of patients with multiple myeloma (MM) treated annually at a treatment facility (volume) and all-cause mortality (outcome). Methods Using the National Cancer Database, we identified patients diagnosed with MM between 2003 and 2011. We classified the facilities by quartiles (Q; mean patients with MM treated per year): Q1: < 3.6; Q2: 3.6 to 6.1, Q3: 6.1 to 10.3, and Q4: > 10.3. We used random intercepts to account for clustering of patients within facilities and Cox regression to determine the volume-outcome relationship, adjusting for demographic (sex, age, race, ethnicity), socioeconomic (income, education, insurance type), geographic (area of residence, treatment facility location, travel distance), and comorbid (Charlson-Deyo score) factors and year of diagnosis. Results There were 94,722 patients with MM treated at 1,333 facilities. The median age at diagnosis was 67 years, and 54.7% were men. The median annual facility volume was 6.1 patients per year (range, 0.2 to 109.9). The distribution of patients according to facility volume was: Q1: 5.2%, Q2: 12.6%, Q3: 21.9%, and Q4: 60.3%. The unadjusted median overall survival by facility volume was: Q1: 26.9 months, Q2: 29.1 months, Q3: 31.9 months, and Q4: 49.1 months ( P < .001). Multivariable analysis showed that facility volume was independently associated with all-cause mortality. Compared with patients treated at Q4 facilities, patients treated at lower-quartile facilities had a higher risk of death (Q3 hazard ratio [HR], 1.12 [95% CI, 1.08 to 1.16]; Q2 HR, 1.17 [95% CI, 1.12 to 1.21]; Q1 HR, 1.22 [95% CI, 1.17 to 1.28]). Conclusion Patients who were treated for MM at higher-volume facilities had a lower risk of mortality compared with those who were treated at lower-volume facilities.

Transcatheter aortic valve replacement (TAVR) is a transformational and rapidly evolving treatment for patients with aortic stenosis who require valve replacement. Novel technological advancements have made this percutaneous minimally invasive therapy a first-line treatment for many patients at extreme risk for conventional cardiac surgery. New devices and improvements in existing devices have reduced procedural complications, and scientific trials are investigating the role of TAVR in lower-risk aortic stenosis populations, in patients with aortic regurgitation, and in patients with bicuspid aortic valve disease. Finally, there is intense interest in identifying patients in whom the risk-benefit ratio of TAVR is not favorable and should not be performed.

Background: The frequency of pulmonary vein stenosis (PVS) after ablation for atrial fibrillation has decreased, but it remains a highly morbid condition. Although treatment strategies including pulmonary vein dilation and stenting have been described, the long-term impacts of these interventions are unknown. We evaluated the presentation of severe PVS, and examined the risk for restenosis after intervention using either balloon angioplasty (BA) alone or BA with stenting. Methods: This was a prospective, observational study of 124 patients with severe PVS evaluated between 2000 and 2014. Results: All 124 patients were identified as having severe PVS by computed tomography in 219 veins. One hundred two patients (82%) were symptomatic at diagnosis. The most common symptoms were dyspnea (67%), cough (45%), fatigue (45%), and decreased exercise tolerance (45%). Twenty-seven percent of patients experienced hemoptysis. Ninety-two veins were treated with BA, 86 were treated with stenting, and 41 veins were not treated. A 94% acute procedural success rate was observed and did not differ by initial management. Major procedural complications occurred in 4 of the 113 patients (3.5%) who underwent invasive assessment, and minor complications occurred in 15 patients (13.3%). Overall, 42% of veins developed restenosis including 27% of veins (n=23) treated with stenting and 57% of veins (n=52) treated with BA. The 3-year overall rate of restenosis was 37%, with 49% of BA-treated veins and 25% of stented veins developing restenosis (hazard ratio, 2.77; 95% confidence interval, 1.72–4.45; P <0.001). After adjustment for age, CHA2DS2-VASc score, hypertension, and the time period of the study, there was still a significant difference in the risk of restenosis for BA versus stenting (hazard ratio, 2.46; 95% confidence interval, 1.47–4.12; P <0.001). Conclusions: The diagnosis of PVS is challenging because of nonspecific symptoms and the need for dedicated pulmonary vein imaging. There is no difference in acute success by type of initial intervention; however, stenting significantly reduces the risk of subsequent pulmonary vein restenosis in comparison with BA.