Environmental Impact of Prostate Magnetic Resonance Imaging and Transrectal Ultrasound Guided Prostate Biopsy.

BACKGROUND: Reducing low-value clinical care is an important strategy to mitigate environmental pollution caused by health care. OBJECTIVE: To estimate the environmental impacts associated with prostate magnetic resonance imaging (MRI) and prostate biopsy. DESIGN, SETTING, AND PARTICIPANTS: We performed a cradle-to-grave life cycle assessment of prostate biopsy. Data included materials and energy inventory, patient and staff travel contributed by prostate MRI, transrectal ultrasound guided prostate biopsy, and pathology analysis. We compared environmental emissions across five clinical scenarios: multiparametric MRI (mpMRI) of the prostate with targeted and systematic biopsies (baseline), mpMRI with targeted biopsy cores only, systematic biopsy without MRI, mpMRI with systematic biopsy, and biparametric MRI (bpMRI) with targeted and systematic biopsies. We estimated the environmental impacts associated with reducing the overall number and varying the approach of a prostate biopsy by using MRI as a triage strategy or by omitting MRI. The study involved academic medical centers in the USA, outpatient urology clinics, health care facilities, medical staff, and patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Greenhouse gas emissions (CO2 equivalents, CO2e), and equivalents of coal and gasoline burned were measured. RESULTS AND LIMITATIONS: In the USA, a single transrectal prostate biopsy procedure including prostate MRI, and targeted and systematic biopsies emits an estimated 80.7 kg CO2e. An approach of MRI targeted cores alone without a systematic biopsy generated 76.2 kg CO2e, a systematic 12-core biopsy without mpMRI generated 36.2 kg CO2e, and bpMRI with targeted and systematic biopsies generated 70.5 kg CO2e; mpMRI alone contributed 42.7 kg CO2e (54.3% of baseline scenario). Energy was the largest contributor, with an estimated 38.1 kg CO2e, followed by staff travel (20.7 kg CO2e) and supply production (11.4 kg CO2e). Performing 100 000 fewer unnecessary biopsies would avoid 8.1 million kg CO2e, the equivalent of 4.1 million liters of gasoline consumed. Per 100 000 patients, the use of prostate MRI to triage prostate biopsy and guide targeted biopsy cores would save the equivalent of 1.4 million kg of CO2 emissions, the equivalent of 700 000 l of gasoline consumed. This analysis was limited to prostate MRI and biopsy, and does not account for downstream clinical management. CONCLUSIONS: A prostate biopsy contributes a calculable environmental footprint. Modifying or reducing the number of biopsies performed through existing evidence-based approaches would decrease health care pollution from the procedure. PATIENT SUMMARY: We estimated that prostate magnetic resonance imaging (MRI) with a prostate biopsy procedure emits the equivalent of 80.7 kg of carbon dioxide. Performing fewer unnecessary prostate biopsies or using prostate MRI as a tool to decide which patients should have a prostate biopsy would reduce procedural greenhouse gas emissions and health care pollution.

Determinants of Active Surveillance in Patients With Small Renal Masses.

OBJECTIVE: To evaluate trends in the utilization of active surveillance (AS) in a nationally representative cancer database. AS has been increasingly recognized as an effective strategy for patients with small renal masses but little is known about national usage patterns. METHODS: We identified patients with clinical T1a renal masses within the National Cancer Database in 2010 through 2014. Patients were classified according to initial management strategy received including AS, surgery, ablation, or other treatment. We characterized time trends in the use of AS vs definitive therapy and examined clinical and socio-demographic determinants of AS among patients with small renal masses using multivariable logistic regression models. RESULTS: We identified 59,189 patients who satisfied the inclusion criteria. Of the total cohort, 1733 (2.9%) individuals received initial management with AS, while 57,456 (97.1%) received definitive treatment. Surveillance rates remained below 5% in all years. On multivariate analysis, patient age (OR: 1.08, 95% CI 1.08-1.09), smaller tumor size of <2 cm vs ≥2 cm (OR: 2.43, 95% CI: 2.20-2.7, P < .0001), management at an academic center vs community center (OR: 2.05, 95% CI: 1.83-2.29), and African American vs Caucasian race (OR: 1.56, 95% CI:1.35-1.80) were independently associated with use of AS as initial management. CONCLUSION: In a representative national cohort of patients with small renal masses, we observed clinical and facility-level differences in the utilization of active surveillance in patients with T1a renal masses. Further investigation is warranted to better understand the forces underlying initial management decisions for patients with small renal masses.

Development of realistic physical breast phantoms matched to virtual breast phantoms based on human subject data.

PURPOSE: Physical phantoms are essential for the development, optimization, and evaluation of x-ray breast imaging systems. Recognizing the major effect of anatomy on image quality and clinical performance, such phantoms should ideally reflect the three-dimensional structure of the human breast. Currently, there is no commercially available three-dimensional physical breast phantom that is anthropomorphic. The authors present the development of a new suite of physical breast phantoms based on human data. METHODS: The phantoms were designed to match the extended cardiac-torso virtual breast phantoms that were based on dedicated breast computed tomography images of human subjects. The phantoms were fabricated by high-resolution multimaterial additive manufacturing (3D printing) technology. The glandular equivalency of the photopolymer materials was measured relative to breast tissue-equivalent plastic materials. Based on the current state-of-the-art in the technology and available materials, two variations were fabricated. The first was a dual-material phantom, the Doublet. Fibroglandular tissue and skin were represented by the most radiographically dense material available; adipose tissue was represented by the least radiographically dense material. The second variation, the Singlet, was fabricated with a single material to represent fibroglandular tissue and skin. It was subsequently filled with adipose-equivalent materials including oil, beeswax, and permanent urethane-based polymer. Simulated microcalcification clusters were further included in the phantoms via crushed eggshells. The phantoms were imaged and characterized visually and quantitatively. RESULTS: The mammographic projections and tomosynthesis reconstructed images of the fabricated phantoms yielded realistic breast background. The mammograms of the phantoms demonstrated close correlation with simulated mammographic projection images of the corresponding virtual phantoms. Furthermore, power-law descriptions of the phantom images were in general agreement with real human images. The Singlet approach offered more realistic contrast as compared to the Doublet approach, but at the expense of air bubbles and air pockets that formed during the filling process. CONCLUSIONS: The presented physical breast phantoms and their matching virtual breast phantoms offer realistic breast anatomy, patient variability, and ease of use, making them a potential candidate for performing both system quality control testing and virtual clinical trials.