Clinical acceptability of automatically generated lymph node levels and structures of deglutition and mastication for head and neck radiation therapy.

Background and Purpose: Auto-contouring of complex anatomy in computed tomography (CT) scans is a highly anticipated solution to many problems in radiotherapy. In this study, artificial intelligence (AI)-based auto-contouring models were clinically validated for lymph node levels and structures of swallowing and chewing in the head and neck. Materials and Methods: CT scans of 145 head and neck radiotherapy patients were retrospectively curated. One cohort (n = 47) was used to analyze seven lymph node levels and the other (n = 98) used to analyze 17 swallowing and chewing structures. Separate nnUnet models were trained and validated using the separate cohorts. For the lymph node levels, preference and clinical acceptability of AI vs human contours were scored. For the swallowing and chewing structures, clinical acceptability was scored. Quantitative analyses of the test sets were performed for AI vs human contours for all structures using overlap and distance metrics. Results: Median Dice Similarity Coefficient ranged from 0.77 to 0.89 for lymph node levels and 0.86 to 0.96 for chewing and swallowing structures. The AI contours were superior to or equally preferred to the manual contours at rates ranging from 75% to 91%; there was not a significant difference in clinical acceptability for nodal levels I-V for manual versus AI contours. Across all AI-generated lymph node level contours, 92% were rated as usable with stylistic to no edits. Of the 340 contours in the chewing and swallowing cohort, 4% required minor edits. Conclusions: An accurate approach was developed to auto-contour lymph node levels and chewing and swallowing structures on CT images for patients with intact nodal anatomy. Only a small portion of test set auto-contours required minor edits.

Management of chordoma and chondrosarcoma with definitive dose-escalated single-fraction spine stereotactic radiosurgery.

PURPOSE: The management of chordoma or chondrosarcoma involving the spine is often challenging due to adjacent critical structures and tumor radioresistance. Spine stereotactic radiosurgery (SSRS) has radiobiologic advantages compared with conventional radiotherapy, though there is limited evidence on SSRS in this population. We sought to characterize the long-term local control (LC) of patients treated with SSRS. METHODS: We retrospectively reviewed patients with chordoma or chondrosarcoma treated with dose-escalated SSRS, defined as 24 Gy in 1 fraction to the gross tumor volume. Overall survival (OS) was calculated by Kaplan-Meier functions. Competing risk analysis using the cause-specific hazard function estimated LC time. RESULTS: Fifteen patients, including 12 with chordoma and 3 with chondrosarcoma, with 22 lesions were included. SSRS intent was definitive, single-modality in 95% of cases (N = 21) and post-operative in 1 case (5%). After a median censored follow-up time of 5 years (IQR 4 to 8 years), median LC time was not reached (IQR 8 years to not reached), with LC rates of 100%, 100%, and 90% at 1 year, 2 years, and 5 years. The median OS was 8 years (IQR 3 years to not reached). Late grade 3 toxicity occurred after 23% of treatments (N = 5, fracture), all of which were managed successfully with stabilization. CONCLUSION: Definitive dose-escalated SSRS to 24 Gy in 1 fraction appears to be a safe and effective treatment for achieving durable local control in chordoma or chondrosarcoma involving the spine, and may hold particular importance as a low-morbidity alternative to surgery in selected cases.

Automated contouring and statistical process control for plan quality in a breast clinical trial.

Background and purpose: Automatic review of breast plan quality for clinical trials is time-consuming and has some unique challenges due to the lack of target contours for some planning techniques. We propose using an auto-contouring model and statistical process control to independently assess planning consistency in retrospective data from a breast radiotherapy clinical trial. Materials and methods: A deep learning auto-contouring model was created and tested quantitatively and qualitatively on 104 post-lumpectomy patients' computed tomography images (nnUNet; train/test: 80/20). The auto-contouring model was then applied to 127 patients enrolled in a clinical trial. Statistical process control was used to assess the consistency of the mean dose to auto-contours between plans and treatment modalities by setting control limits within three standard deviations of the data's mean. Two physicians reviewed plans outside the limits for possible planning inconsistencies. Results: Mean Dice similarity coefficients comparing manual and auto-contours was above 0.7 for breast clinical target volume, supraclavicular and internal mammary nodes. Two radiation oncologists scored 95% of contours as clinically acceptable. The mean dose in the clinical trial plans was more variable for lymph node auto-contours than for breast, with a narrower distribution for volumetric modulated arc therapy than for 3D conformal treatment, requiring distinct control limits. Five plans (5%) were flagged and reviewed by physicians: one required editing, two had clinically acceptable variations in planning, and two had poor auto-contouring. Conclusions: An automated contouring model in a statistical process control framework was appropriate for assessing planning consistency in a breast radiotherapy clinical trial.

Parametric delineation uncertainties contouring (PDUC) modeling on CT scans of prostate cancer patients.

PURPOSE: Variability in contouring contributes to large variations in radiation therapy planning and treatment outcomes. The development and testing of tools to automatically detect contouring errors require a source of contours that includes well-understood and realistic errors. The purpose of this work was to develop a simulation algorithm that intentionally injects errors of varying magnitudes into clinically accepted contours and produces realistic contours with different levels of variability. METHODS: We used a dataset of CT scans from 14 prostate cancer patients with clinician-drawn contours of the regions of interest (ROI) of the prostate, bladder, and rectum. Using our newly developed Parametric Delineation Uncertainties Contouring (PDUC) model, we automatically generated alternative, realistic contours. The PDUC model consists of the contrast-based DU generator and a 3D smoothing layer. The DU generator transforms contours (deformation, contraction, and/or expansion) as a function of image contrast. The generated contours undergo 3D smoothing to obtain a realistic look. After model building, the first batch of auto-generated contours was reviewed. Editing feedback from the reviews was then used in a filtering model for the auto-selection of clinically acceptable (minor-editing) DU contours. RESULTS: Overall, C values of 5 and 50 consistently produced high proportions of minor-editing contours across all ROI compared to the other C values (0.936 ± $ \pm \;$ 0.111 and 0.552 ± $ \pm \;$ 0.228, respectively). The model performed best on the bladder, which had the highest proportion of minor-editing contours (0.606) of the three ROI. In addition, the classification AUC for the filtering model across all three ROI is 0.724 ± $ \pm \;$ 0.109. DISCUSSION: The proposed methodology and subsequent results are promising and could have a great impact on treatment planning by generating mathematically simulated alternative structures that are clinically relevant and realistic enough (i.e., similar to clinician-drawn contours) to be used in quality control of radiation therapy.

Physician Perspectives on Telemedicine in Radiation Oncology.

Purpose: Telemedicine enthusiasm and uptake in radiation oncology rapidly increased during the COVID-19 pandemic, but it is unclear if and how telemedicine should be used after the COVID-19 public health emergency ends is unclear. Herein, we report on our institution's provider experience after the mature adoption of telemedicine. Methods and Materials: We distributed a survey to all radiation oncology attending physicians at our institution in October 2021 to assess satisfaction, facilitators, and barriers to telemedicine implementation. We performed quantitative and qualitative analyses to characterize satisfaction and identify influencing factors whether telemedicine is employed. We calculated the average proportion of visits that providers expected to be appropriately performed with telemedicine for each disease site and visit type. Results: A total of 60 of the 82 eligible radiation oncologists (73%) responded to the survey, of whom 78% were satisfied with telemedicine in the radiation oncology department and 83% wished to continue offering video visits after the COVID-19 public health emergency ends. Common patient factors influencing whether physicians offer telemedicine include the patient's travel burden, patient preferences, and whether a physical examination is required. Approximately 20% of new consultations and 50% of weekly management visits were estimated to be appropriate for telemedicine. The central nervous system/pediatrics and thoracic faculty considered telemedicine appropriate for the greatest proportion of new consultations, and 93% of respondents felt comfortable determining whether telemedicine was appropriate. Conclusions: Surveyed radiation oncologists were satisfied with telemedicine in their practice, and wished to continue offering video visits in the future. Our data suggest that payers should continue to support this patient-centered technology.

Patient, physician, and policy factors underlying variation in use of telemedicine for radiation oncology cancer care.

BACKGROUND: Oncology telemedicine was implemented rapidly after COVID-19. We examined multilevel correlates and outcomes of telemedicine use for patients undergoing radiotherapy (RT) for cancer. METHODS: Upon implementation of a telemedicine platform at a comprehensive cancer center, we analyzed 468 consecutive patient RT courses from March 16, 2020 to June 1, 2020. Patients were categorized as using telemedicine during ≥1 weekly oncologist visits versus in-person oncologist management only. Temporal trends were evaluated with Cochran-Armitage tests; chi-squared test and multilevel multivariable logistic models identified correlates of use and outcomes. RESULTS: Overall, 33% used telemedicine versus 67% in-person only oncologist management. Temporal trends (ptrend  < 0.001) correlated with policy changes: uptake was rapid after local social-distancing restrictions, reaching peak use (35% of visits) within 4 weeks of implementation. Use declined to 15% after national "Opening Up America Again" guidelines. In the multilevel model, patients more likely to use telemedicine were White non-Hispanic versus Black or Hispanic (odds ratio [OR] = 2.20, 95% confidence interval [CI] 1.03-4.72; p = 0.04) or receiving ≥6 fractions of RT versus 1-5 fractions (OR = 4.49, 95% CI 2.29-8.80; p < 0.001). Model intraclass correlation coefficient demonstrated 43% utilization variation was physician-level driven. Treatment toxicities and 30-day emergency visits or unplanned hospitalizations did not differ for patients using versus not using telemedicine (p > 0.05, all comparisons). CONCLUSION: Though toxicities were similar with telemedicine oncology management, there remained lower uptake among non-White patients. Continuing strategies for oncology telemedicine implementation should address multilevel patient, physician, and policy factors to optimize telemedicine's potential to surmount-and not exacerbate-barriers to quality cancer care.

Geographic Access to Radiation Therapy Facilities in the United States.

PURPOSE: The current distribution of radiation therapy (RT) facilities in the United States is not well established. A comprehensive inventory of U.S. RT facilities was last assessed in 2005, based on data from state regulatory agencies and dosimetric quality assurance bodies. We updated this database to characterize population-level measures of geographic access to RT and analyze changes over the past 15 years. METHODS AND MATERIALS: We compiled data from regulatory and accrediting organizations to identify U.S. facilities with linear accelerators used to treat humans in 2018 to 2020. Addresses were geocoded and analyzed with Geographic Information Services software. Geographic access was characterized by assessing the Euclidian distance between ZIP code tabulation areas/county centroids and RT facilities. Populations were assigned to each county to estimate the effect of facility changes at the population level. Logistic regressions were performed to identify features associated with increased distance to RT and associated with regions that gained an RT facility between the 2 time points studied. RESULTS: In 2020, a total of 2313 U.S. RT facilities were reported, compared with 1987 in 2005, representing a 16.4% growth in facilities over nearly 15 years. Based on population attribution to the centroids of ZIP Code Tabulation Areas, 77.9% of the U.S. population lives within 12.5 miles of an RT facility, and 1.8% of the U.S. population lives more than 50 miles from an RT facility. We found that increased distance to RT was associated with nonmetro status, less insurance, older median age, and less populated regions. Between 2005 and 2020, the population living within 12.5 miles from an RT facility increased by 2.1 percentage points, whereas the population living furthest from RT facilities decreased 0.6 percentage points. Regions with improved geographic RT access are more likely to be higher income and better insured. CONCLUSIONS: The percentage of the U.S. population with limited geographic access to RT is 1.8%. We found that people benefiting from improved access to RT facilities are more economically advantaged, suggesting disparities in geographic access may not improve without intervention.

Drivers of Medicare Spending: A 15-Year Review of Radiation Oncology Charges Allowed by the Medicare Physician/Supplier Fee-for-Service Program Compared With Other Specialties.

PURPOSE: In 2019, the Centers for Medicare and Medicaid Services proposed a new radiation oncology alternative payment model aimed at reducing expenditures. We examined changes in aggregate physician Medicare charges allowed per specialty to provide contemporary context to proposed changes and hypothesize that radiation oncology charges remained stable through 2017. METHODS AND MATERIALS: Medicare physician/supplier utilization, program payments, and balance billing for original Medicare beneficiaries, by physician specialty, were analyzed from 2002 to 2017. Total allowed charges under the physician/supplier fee-for-service program, inflation-adjusted charges, and percent of total charges billed per specialty were examined. We adjusted for inflation using the consumer price index for medical care from the US Bureau of Labor Statistics. RESULTS: Total allowed charges increased from $83 billion in 2002 to $138 billion in 2017. The specialties accounting for the most charges billed to Medicare were internal medicine and ophthalmology. Radiation oncology charges accounted for 1.2%, 1.6%, and 1.4% of total charges allowed by Medicare in 2002, 2012, and 2017, respectively. Radiation oncology charges allowed increased 44% from 2002 to 2012 ($987.6 million to $1.42 billion) but decreased by 19% from 2012 to 2017 ($1.15 billion), adjusted for inflation. Total charges allowed by internal medicine decreased 2% from 2002 to 2012 ($8.53 to $8.36 billion), adjusted for inflation, and decreased 16% from 2012 to 2017 ($7.05 billion). When adjusting for inflation, ophthalmology charges increased 18% from 2002 to 2012 ($4.53 to $5.36 billion) and increased 3% from 2012 to 2017 ($5.5 billion). CONCLUSIONS: Radiation oncology physician charges represent a small fraction of total Medicare expenses and are not a driver for Medicare spending. Aggregate inflation-adjusted charges by radiation oncology have dramatically declined in the past 5 years and represent a stable fraction of total Medicare charges. The need to target radiation oncology with cost-cutting measures may be overstated.

Predictors of urinary toxicity with MRI-assisted radiosurgery for low-dose-rate prostate brachytherapy.

PURPOSE: MRI-assisted radiosurgery (MARS) is a modern technique for prostate brachytherapy that provides superior soft tissue contrast. The purpose of this analysis was to evaluate treatment planning factors associated with urinary toxicity, particularly damage to the membranous urethra (MUL) and external urethral sphincter (EUS), after MARS. MATERIAL AND METHODS: We retrospectively reviewed 227 patients treated with MARS. Comparisons were made between several factors including preimplantation length of the MUL and EUS dosimetric characteristics after implantation with longitudinal changes in American Urological Association (AUA) urinary symptom score. RESULTS: Rates of grade 3 urinary incontinence and obstructive urinary symptoms were 4% and 2%. A piecewise mixed univariate model revealed that MUL and V200, V150, V125, and D5 to the EUS were all associated with increased rates of urinary toxicity over time. On univariate logistic regression, MUL >14.2 mm (odds ratio [OR] 2.03 per cm3, 95% confidence interval [CI] 1.10-3.77, p = 0.025), V125 to the EUS (OR 3.21 cm3, 95% CI 1.18-8.71, p = 0.022), and use of the I-125 isotope (OR 3.45, 95% CI 1.55-7.70, p = 0.001) were associated with subacute urinary toxicity (i.e., that occurring at 4-8 months). Optimal dose-constraint limits to the EUS were determined to be V200 < 0.04 cm3 (p = 0.002), V150 < 0.12 cm3 (p = 0.041), V125 < 0.45 cm3 (p = 0.033), D30 < 160 Gy (p = 0.004), and D5 < 218 Gy (p = 0.016). CONCLUSIONS: MARS brachytherapy provides detailed anatomic information for treatment planning, implantation, and quality assurance. Overall rates of urinary toxicity are low; however, several dosimetric variables associated with the EUS were found to correlate with urinary toxicity.

Medicare Cancer Screening in the Context of Clinical Guidelines: 2000 to 2012.

OBJECTIVES: Cancer screening is a ubiquitous and controversial public health issue, particularly in the elderly population. Despite extensive evidence-based guidelines for screening, it is unclear how cancer screening has changed in the Medicare population over time. We characterize trends in cancer screening for the most common cancer types in the Medicare fee-for-service (FFS) program in the context of conflicting guidelines from 2000 to 2012. MATERIALS AND METHODS: We performed a descriptive analysis of retrospective claims data from the Medicare FFS program based on billing codes. Our data include all claims for Medicare part B beneficiaries who received breast, colorectal (CRC), or prostate cancer screening from 2000 to 2012 based on billing codes. We utilize a Monte Carlo permutation method to detect changes in screening trends. RESULTS: In total, 231,416,732 screening tests were analyzed from 2000 to 2012, representing an average of 436.8 tests per 1000 beneficiaries per year. Mammography rates declined 7.4%, with digital mammography extensively replacing film. CRC cancer screening rates declined overall. As a percentage of all CRC screening tests, colonoscopy grew from 32% to 71%. Prostate screening rates increased 16% from 2000 to 2007, and then declined to 7% less than its 2000 rate by 2012. DISCUSSION: Both the aggressiveness of screening guidelines and screening rates for the Medicare FFS population peaked and then declined from 2000 to 2012. However, guideline publications did not consistently precede utilization trend shifts. Technology adoption, practical and financial concerns, and patient preferences may have also contributed to the observed trends. Further research should be performed on the impact of multiple, conflicting guidelines in cancer screening.

Use of Point-of-Care Ultrasound in the Emergency Department: Insights From the 2012 Medicare National Payment Data Set.

OBJECTIVES: Point-of-care ultrasound is a valuable tool with potential to expedite diagnoses and improve patient outcomes in the emergency department. However, little is known about national patterns of adoption. This study examined nationwide point-of-care ultrasound reimbursement among emergency medicine (EM) practitioners and examined regional and practitioner level variations. METHODS: Data from the 2012 Center for Medicare and Medicaid Services Fee-for-Service Provider Utilization and Payment Data include all practitioners who received more than 10 Medicare Part B fee-for-service reimbursements for any Healthcare Common Procedure Coding System code in 2012. Odds ratios (ORs) and descriptive statistics were calculated to assess relationships between ultrasound reimbursement and practice location, nearby presence of an EM residency, and time elapsed since practitioner graduation. RESULTS: Of 52,928 unique EM practitioners, 391 (0.7%) received limited ultrasound reimbursements for a total of 16,389 scans in 2012. Urban counties had an OR of 5.4 (95% confidence interval, 3.8-7.8) for receiving point-of-care ultrasound reimbursements compared to rural counties. Counties with an EM residency had an OR of 84.7 (95% confidence interval, 42.6-178.8) for reimbursement compared to counties without. The OR for receiving reimbursement was independent of medical school graduation year (P = .83); however, recent graduates performed more scans (P = .02). CONCLUSIONS: A small minority of EM practitioners received reimbursements for point-of-care ultrasound from Medicare beneficiaries. These practitioners were more likely to reside in urban and academic settings. Future efforts should assess the degree to which our findings reflect either low point-of-care ultrasound use or low rates of billing for ultrasound examinations that are performed.

The cost of cancer-related physician services to Medicare.

Although physician services represent a substantial portion of cancer care costs, little is known about trends in the costs of physician cancer services in the fee-for-service Medicare program. We analyzed aggregated data from all Part B Medicare claims for physician and supplier services attributed to cancer patients from 1999 to 2012 to characterize how billing and payments have changed over time for the most common cancer types. Billing and expenditure data are from the Medicare Statistical Supplement, and age-adjusted incidence data are from SEER. Physician services for cancer patients grew from $7.6 billion in 1999 to $12.3 billion in 2012 (60 percent increase). Reimbursements for physician and supplier services for cancer treatment in Medicare Part B beneficiaries steadily grew from 1999 to 2005 and then plateaued through 2012, led by a decrease in reimbursements for prostate cancer care. These trends may reflect shifts toward hospital-based care or changes in aggressiveness of care.