Browsing by Author "Erkanli, Alaattin"

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    A mathematical framework to quantitatively balance clinical and radiation risk in Computed Tomography
    (2021-12-01) Ria, Francesco; Zhang, Anru; Lerebours, Reginald; Erkanli, Alaattin; Solomon, justin; Marin, Daniele; Samei, Ehsan
    Purpose: Risk in medical imaging is a combination of radiation risk and clinical risk, which is largely driven by the effective diagnosis. While radiation risk has traditionally been the main focus of Computed Tomography (CT) optimization, such a goal cannot be achieved without considering clinical risk. The purpose of this study was to develop a comprehensive mathematical framework that considers both radiation and clinical risks based on the specific task, the investigated disease, and the interpretive performance (i.e., false positive and false negative rates), tested across a representative clinical CT population. Methods and Materials: The proposed mathematical framework defined the radiation risk to be a linear function of the radiation dose, the population prevalence of the disease, and the false positive rate. The clinical risk was defined to be a function of the population prevalence, the expected life-expectancy loss for an incorrect diagnosis, and the interpretative performance in terms of the AUC as a function of radiation dose. A Total Risk (TR) was defined as the sum of the radiation risk and the clinical risk. With IRB approval, the mathematical function was applied to a dataset of 80 adult CT studies investigating localized stage liver cancer (LLC) for a specific false positive rate of 5% reconstructed with both Filtered Back Projection (FBP) and Iterative Reconstruction (IR) algorithm. Linear mixed effects models were evaluated to determine the relationship between radiation dose and radiation risk and interpretative performance, respectively. Lastly, the analytical minimum of the TR curve was determined and reported. Results: TR is largely affected by clinical risk for low radiation dose whereas radiation risk is dominant at high radiation dose. Concerning the application to the LLC population, the median minimum risk in terms of mortality per 100 patients was 0.04 in FBP and 0.03 in IR images; the corresponding CTDIvol values were 38.5 mGy and 25.7 mGy, respectively. Conclusions: The proposed mathematical framework offers a complete quantitative description of risk in CT enabling a comprehensive risk-to-benefit assessment essential in the effective justification of radiological procedures and in the design of optimal clinical protocols. Clinical Relevance/Application: The quantification of both radiation and clinical risk using comparable units allows the calculation of the overall risk paving the road towards a comprehensive risk-to-benefit assessment in CT.
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    A Method for Grouping Emergency Department Visits by Severity and Complexity.
    (The western journal of emergency medicine, 2020-08-21) Theiling, Brent; Kennedy, Kendrick; Limkakeng, Alexander; Manandhar, Pratik; Erkanli, Alaattin; Pitts, Stephen
    INTRODUCTION:Triage functions to quickly prioritize care and sort patients by anticipated resource needs. Despite widespread use of the Emergency Severity Index (ESI), there is still no universal standard for emergency department (ED) triage. Thus, it can be difficult to objectively assess national trends in ED acuity and resource requirements. We sought to derive an ESI from National Hospital Ambulatory Medical Care Survey (NHAMCS) survey items (NHAMCS-ESI) and to assess the performance of this index with respect to stratifying outcomes, including hospital admission, waiting times, and ED length of stay (LOS). METHODS:We used data from the 2010-2015 NHAMCS, to create a measure of ED visit complexity based on variables within NHAMCS. We used NHAMCS data on chief complaint, vitals, resources used, interventions, and pain level to group ED visits into five levels of acuity using a stepwise algorithm that mirrored ESI. In addition, we examined associations of NHAMCS-ESI with typical indicators of acuity such as waiting time, LOS, and disposition. The NHAMCS-ESI categorization was also compared against the "immediacy" variable across all of these outcomes. Visit counts used weighted scores to estimate national levels of ED visits. RESULTS:The NHAMCS ED visits represent an estimated 805,726,000 ED visits over this time period. NHAMCS-ESI categorized visits somewhat evenly, with most visits (42.5%) categorized as a level 3. The categorization pattern is distinct from that of the "immediacy" variable within NHAMCS. Of admitted patients, 89% were categorized as NHAMCS-ESI level 2-3. Median ED waiting times increased as NHAMCS-ESI levels decreased in acuity (from approximately 14 minutes to 25 minutes). Median LOS decreased as NHAMCS-ESI decreased from almost 200 minutes for level 1 patients to nearly 80 minutes for level 5 patients. CONCLUSION:We derived an objective tool to measure an ED visit's complexity and resource use. This tool can be validated and used to compare complexity of ED visits across hospitals and regions, and over time.
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    Clinical and radiation risk across one million patients in Computed Tomography: influence of age, size, and race
    (2023-11-26) Ria, Francesco; Lerebours, Reginald; Zhang, Anru; Erkanli, Alaattin; Abadi, Ehsan; SOLOMON, justin; Marin, Daniele; Samei, Ehsan
    Purpose. We recently developed a mathematical model to balance radiation risk and clinical risk, namely the risk of misdiagnosis due to insufficient image quality. In this work, we applied this model to a population of one million CT imaging cases to evaluate the risk stratification with different ages, sexes, and races. Materials and Methods. The demographics were informed by literature and census information simulating a clinical liver cancer population. The Total Risk (TR) was calculated as the linear combination of radiation risk and clinical risk. The model included factors for the radiation burden for different age and sex; the prevalence of the disease; the false positive rate; the expected life-expectancy loss for an incorrect diagnosis for different ages, sex, and race; and a typical false positive rate of 5%. It was assumed that each case received an average radiologist interpretative performance of 0.75 AUC for a hypothetical lesion without any changes in radiation dose beyond routine practice. We further, for each patient, simulated 2,000 imaging conditions with CTDIvol varying from 0.1 and 200 mGy with 0.1 mGy increments. Per each CTDIvol value, the anticipated AUC was calculated by applying the established asymptotic relationships between CTDIvol and image quality. The AUC distribution was then used to calculate the theoretical minimum total risk (TRmin) per each patient. Results. For the routine practice, the median theoretical total risk was estimated to be 0.058 deaths per 100 patients (range: 0.002 – 0.154) comprising of the median radiation risk of 0.009 (range: 0.001 – 0.069), and of the median clinical risk of 0.049 (range: 7.0x10-5 – 0.094). Considering the varying scanner output conditions, the median TRmin was 0.054 deaths per 100 patients for White male patients, 0.054 for Blacks, 0.057 for Hispanics, and 0.065 for Asians. For female patients, the median TRmin values were 0.049, 0.056, 0.054, and 0.061 deaths per 100 patients, respectively. Conclusion. For each demography condition, the clinical risk was found to largely outweigh the radiation risk by at least 500%. Total risk showed different stratifications with patient age and race. Clinical Relevance Statement. To optimize CT conditions for specific patients and/or population, both radiation risk and clinical risks should be all accounted for together with demographic information. We demonstrated a methodology that allows a complete depiction of total risk in CT, considering radiation and clinical risks at comparable units, and patient demographic.
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    Comparative Risk Assessment of Clinical and Radiation Risk across a Cohort of Patient and Individualized Risk Optimization
    (https://aapm.onlinelibrary.wiley.com/doi/epdf/10.1002/mp.16525, 2023-07-23) Ria, Francesco; Lerebours, Reginald; Zhang, Anru; Erkanli, Alaattin; Abadi, Ehsan; SOLOMON, justin; Marin, daniele; Samei, Ehsan
    Purpose Informed by a recent mathematical framework, we formulated an imaging strategy to balance interpretative performance-based clinical risk (i.e., false positive and false negative rates) and radiation risk as a risk-versus-risk assessment. The model was applied to a population of one million cases simulating a clinical liver cancer scenario. Moreover, a model was developed to predict individualized risk-versus-risk optimization. Methods The proposed model defined a Total Risk (TR) as the linear combination of radiation risk and clinical risk defined as functions of the radiation burden, the disease prevalence disease, the false positive rate, the expected life-expectancy loss for an incorrect diagnosis, and the radiologist interpretative performance (i.e., AUC). The mathematical framework was applied to a simulated dataset of 1,000,000 CT studies investigating localized stage liver cancer assuming a typical false positive rate of 5% and optimal imaging conditions (AUC=0.75). Demographic information was simulated according with literature and census data including male and female for different patient races (white, black, Asian, and Hispanic). Following BEIR-VII report, organ-specific radiation doses were used to calculate the radiation Risk Index per each patient. The model was then extended to predict the optimal scanner output associated with the TR for specific patients. Results Across all races and sexes, median radiation risk ranged between 0.008 and 0.012 number of deaths per 100 patients; median clinical risk ranged between 0.042 and 0.076; and medial total risk ranged between 0.010 and 0.088 deaths per 100 patients. The mathematical model was then generalized to estimate individualized optimal imaging condition minimizing TR. Conclusion A mathematical framework to describe total risk in CT was robustly tested in a simulated dataset of 1,000,000 CT studies. The results highlighted the dominance of clinical risk at typical CT examination dose levels. The generalization of the mathematical model allowed the prediction of individualized risk optimization.
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    Improving health engagement and lifestyle management for breast cancer survivors with diabetes.
    (Contemporary clinical trials, 2020-05) Shelby, Rebecca A; Dorfman, Caroline S; Arthur, Sarah S; Bosworth, Hayden B; Corsino, Leonor; Sutton, Linda; Owen, Lynda; Erkanli, Alaattin; Keefe, Francis; Corbett, Cheyenne; Kimmick, Gretchen
    Breast cancer survivors with type 2 diabetes are at high risk for cancer recurrence, serious health complications, more severe symptoms, psychological distress, and premature death relative to breast cancer survivors without diabetes. Maintaining glycemic control is critical for decreasing symptoms and preventing serious health problems. Many breast cancer survivors with type 2 diabetes have difficulty maintaining diabetes self-management behaviors and achieving glycemic control. Both cancer and diabetes-related symptoms (e.g., physical symptoms and psychological distress) are often barriers to engaging in diabetes self-management strategies. This study evaluates a novel diabetes coping skills training (DCST) intervention for improving breast cancer survivors' abilities to manage symptoms and adhere to recommended diabetes self-management behaviors. The telephone-based DCST protocol integrates three key theory-based strategies: coping skills training for managing symptoms, adherence skills training, and healthy lifestyle skills training. A randomized clinical trial will test the DCST intervention plus diabetes education by comparing it to diabetes education alone. Symptoms, distress, diabetes self-management behaviors, and self-efficacy will be assessed at baseline and 3, 6, and 12 months. Glycosylated hemoglobin (HbA1c) will be assessed at baseline, 6, and 12 months. This study addresses a critical gap in the care of breast cancer survivors by evaluating a novel behavioral intervention to improve the management of symptoms, adherence, and glycemic control in breast cancer survivors with type 2 diabetes. Special considerations for this medically underserved population are also provided. The findings of this study could lead to significant improvements in clinical care and beneficial outcomes for breast cancer survivors. Trials registration: ClinicalTrials.gov, NCT02970344, registered 11/22/2016.
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    International Image Concordance Study to Compare a Point-of-Care Tampon Colposcope With a Standard-of-Care Colposcope.
    (Journal of lower genital tract disease, 2017-04) Mueller, Jenna L; Asma, Elizabeth; Lam, Christopher T; Krieger, Marlee S; Gallagher, Jennifer E; Erkanli, Alaattin; Hariprasad, Roopa; Malliga, JS; Muasher, Lisa C; Mchome, Bariki; Oneko, Olola; Taylor, Peyton; Venegas, Gino; Wanyoro, Anthony; Mehrotra, Ravi; Schmitt, John W; Ramanujam, Nimmi

    Objective

    Barriers to cervical cancer screening in low-resource settings include lack of accessible, high-quality services, high cost, and the need for multiple visits. To address these challenges, we developed a low-cost, intravaginal, optical cervical imaging device, the point-of-care tampon (POCkeT) colposcope and evaluated whether its performance is comparable with a standard-of-care colposcope.

    Materials and methods

    There were 2 protocols, which included 44 and 18 patients. For the first protocol, white-light cervical images were collected in vivo, blinded by device, and sent electronically to 8 physicians from high-, middle-, and low-income countries. For the second protocol, green-light images were also collected and sent electronically to the highest performing physician from the first protocol who has experience in both a high- and low-income country. For each image, physicians completed a survey assessing cervix characteristics and severity of precancerous lesions. Corresponding pathology was obtained for all image pairs.

    Results

    For the first protocol, average percent agreement between devices was 70% across all physicians. The POCkeT and standard-of-care colposcope images had 37% and 51% agreement with pathology for high-grade squamous intraepithelial lesions (HSILs), respectively. Investigation of HSIL POCkeT images revealed decreased visibility of vascularization and lack of contrast in lesion margins. After changes were made for the second protocol, the 2 devices achieved similar agreement to pathology for HSIL lesions (55%).

    Conclusions

    Based on the exploratory study, physician interpretation of cervix images acquired using a portable, low-cost POCkeT colposcope was comparable to a standard-of-care colposcope.
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    Testing a behavioral intervention to improve adherence to adjuvant endocrine therapy (AET).
    (Contemporary clinical trials, 2019-01) Shelby, Rebecca A; Dorfman, Caroline S; Bosworth, Hayden B; Keefe, Francis; Sutton, Linda; Owen, Lynda; Corsino, Leonor; Erkanli, Alaattin; Reed, Shelby D; Arthur, Sarah S; Somers, Tamara; Barrett, Nadine; Huettel, Scott; Gonzalez, Juan Marcos; Kimmick, Gretchen
    Adjuvant endocrine therapy (AET) is used to prevent recurrence and reduce mortality for women with hormone receptor positive breast cancer. Poor adherence to AET is a significant problem and contributes to increased medical costs and mortality. A variety of problematic symptoms associated with AET are related to non-adherence and early discontinuation of treatment. The goal of this study is to test a novel, telephone-based coping skills training that teaches patients adherence skills and techniques for coping with problematic symptoms (CST-AET). Adherence to AET will be assessed in real-time for 18 months using wireless smart pill bottles. Symptom interference (i.e., pain, vasomotor symptoms, sleep problems, vaginal dryness) and cost-effectiveness of the intervention protocol will be examined as secondary outcomes. Participants (N = 400) will be recruited from a tertiary care medical center or community clinics in medically underserved or rural areas. Participants will be randomized to receive CST-AET or a general health education intervention (comparison condition). CST-AET includes ten nurse-delivered calls delivered over 6 months. CST-AET provides systematic training in coping skills for managing symptoms that interfere with adherence. Interactive voice messaging provides reinforcement for skills use and adherence that is tailored based on real-time adherence data from the wireless smart pill bottles. Given the high rates of non-adherence and recent recommendations that women remain on AET for 10 years, we describe a timely trial. If effective, the CST-AET protocol may not only reduce the burden of AET use but also lead to cost-effective changes in clinical care and improve breast cancer outcomes. Trials registration: ClinicalTrials.gov, NCT02707471, registered 3/3/2016.