Medical workforce in the United States.

This section focuses on the professional workforce comprised of the primary medical specialties that utilize ionizing radiation in their practices. Those discussed include the specialties of radiology and radiation oncology, as well as the subspecialties of radiology, namely diagnostic radiology, interventional radiology, nuclear radiology, and nuclear medicine. These professionals provide essential health care services, for example, the interpretation of imaging studies, the provision of interventional procedures, radionuclide therapeutic treatments, and radiation therapy. In addition, they may be called on to function as part of a radiologic emergency response team to care for potentially exposed persons following radiation events, for example, detonation of a nuclear weapon, nuclear power plant accidents, and transportation incidents. For these reasons, maintenance of an adequate workforce in each of these professions is essential to meeting the nation's future needs. Currently, there is a shortage for all physicians in the medical radiology workforce.

Influence of Geography on Prostate Cancer Treatment.

PURPOSE: Several definitive treatment options are available for prostate cancer, but geographic access to those options is not uniform. We created maps illustrating provider practice patterns relation to patients and assessed the influence of distance to treatment receipt. METHODS AND MATERIALS: The patient cohort was created by searching the National Medicare Database for patients diagnosed and treated for prostate cancer from 2011 to 2014. The provider cohort was created by querying the American Medical Association Physician Masterfile to identify physicians who had treated patients with prostatectomy, intensity modulated radiation therapy (IMRT), brachytherapy, stereotactic body radiation therapy (SBRT), or proton therapy. Maps detailing the location of providers were created for each modality. Multivariate multinomial logistic regressions were used to assess the association between patient-provider distance and probability of treatment. RESULTS: Cohorts consisted of 89,902 patients treated by 5518 physicians. Substantial numbers of providers practicing established modalities (IMRT, prostatectomy, and brachytherapy) were noted in major urban centers, whereas provider numbers were reduced in rural areas, most notably for brachytherapy. Ninety percent of prostate cancer patients lived within 35.1, 28.9, and 55.6 miles of a practitioner of prostatectomy, IMRT, and brachytherapy, respectively. Practitioners of emerging modalities (SBRT and proton therapy) were predominantly concentrated in urban locations, with 90% of patients living within 128 miles (SBRT) and 374.5 miles (proton). Greater distance was associated with decreased probability of treatment (IMRT -3.8% per 10 miles; prostatectomy -2.1%; brachytherapy -2%; proton therapy -1.6%; and SBRT -1.1%). CONCLUSIONS: Geographic disparities were noted for analyzed treatment modalities, and these disparities influenced delivery.

Costs and Complications After a Diagnosis of Prostate Cancer Treated With Time-Efficient Modalities: An Analysis of National Medicare Data.

PURPOSE: Recent trends in payer and patient preferences increasingly incentivize time-efficient (≤2-week treatment time) prostate cancer treatments. METHODS AND MATERIALS: National Medicare claims from January 1, 2011, through December 31, 2014, were analyzed to identify newly diagnosed prostate cancers. Three "radical treatment" cohorts were identified (prostatectomy, brachytherapy, and stereotactic body radiation therapy [SBRT]) and matched to an active surveillance (AS) cohort by using inverse probability treatment weighting via propensity score. Total costs at 1 year after biopsy were calculated for each cohort, and treatment-specific costs were estimated by subtracting total 1-year costs in each radical treatment group from those in the AS group. RESULTS: Mean 1-year adjusted costs were highest among patients receiving SBRT ($26,895), lower for prostatectomy ($23,632), and lowest for brachytherapy ($19,980), whereas those for AS were $9687. Costs of radical modalities varied significantly by region, with the Mid-Atlantic and New England regions having the highest cost ranges (>$10,000) and the West South Central and Mountain regions the lowest range in costs (<$2000). Quantification of toxic effects showed that prostatectomy was associated with higher genitourinary incontinence (hazard ratio [HR] = 10.8 compared with AS) and sexual dysfunction (HR = 3.5), whereas the radiation modalities were associated with higher genitourinary irritation/bleeding (brachytherapy HR = 1.7; SBRT HR = 1.5) and gastrointestinal ulcer/stricture/fistula (brachytherapy HR = 2.7; SBRT HR = 3.0). Overall mean toxicity costs were highest among patients treated with prostatectomy ($3500) followed by brachytherapy ($1847), SBRT ($1327), and AS ($1303). CONCLUSIONS: Time-efficient treatment techniques exhibit substantial variability in toxicity and costs. Furthermore, geographic location substantially influenced treatment costs.

Comparative Toxicities and Cost of Intensity-Modulated Radiotherapy, Proton Radiation, and Stereotactic Body Radiotherapy Among Younger Men With Prostate Cancer.

Purpose To compare the toxicities and cost of proton radiation and stereotactic body radiotherapy (SBRT) with intensity-modulated radiotherapy (IMRT) for prostate cancer among men younger than 65 years of age with private insurance. Methods Using the MarketScan Commercial Claims and Encounters database, we identified men who received radiation for prostate cancer between 2008 and 2015. Patients undergoing proton therapy and SBRT were propensity score-matched to IMRT patients on the basis of clinical and sociodemographic factors. Proportional hazards models compared the cumulative incidence of urinary, bowel, and erectile dysfunction toxicities by treatment. Cost from a payer's perspective was calculated from claims and adjusted to 2015 dollars. Results A total of 693 proton therapy patients were matched to 3,465 IMRT patients. Proton therapy patients had a lower risk of composite urinary toxicity (33% v 42% at 2 years; P < .001) and erectile dysfunction (21% v 28% at 2 years; P < .001), but a higher risk of bowel toxicity (20% v 15% at 2 years; P = .02). Mean radiation cost was $115,501 for proton therapy patients and $59,012 for IMRT patients ( P < .001). A total of 310 SBRT patients were matched to 3,100 IMRT patients. There were no significant differences in composite urinary, bowel, or erectile dysfunction toxicities between SBRT and IMRT patients ( P > .05), although a higher risk of urinary fistula was noted with SBRT (1% v 0.1% at 2 years; P = .009). Mean radiation cost for SBRT was $49,504 and $57,244 for IMRT ( P < .001). Conclusion Among younger men with prostate cancer, proton radiation was associated with significant reductions in urinary toxicity but increased bowel toxicity at nearly twice the cost of IMRT. SBRT and IMRT were associated with similar toxicity profiles; SBRT was modestly less expensive than IMRT.

Implementing an Electronic Data Capture System to Improve Clinical Workflow in a Large Academic Radiation Oncology Practice.

PURPOSE: To describe the feasibility and benefits of implementing a custom radiation oncology electronic data capture (EDC) system in a large academic radiation oncology practice. PATIENTS AND METHODS: A Web-based point-and-click EDC known as Brocade was internally developed and implemented systemwide in 2016. Brocade captures key data elements, such as stage, histology, and patient and treatment characteristics; links this information to radiation dose data extracted from the record and verify system; and creates clinical notes that are automatically exported to the hospital electronic health record. We report the number of unique radiation episodes captured by Brocade in its first full year of implementation and describe the notes generated, toxicities captured, compliance with staging and quality assurance, and time of day in which documentation occurred with Brocade versus our prior human transcription system. RESULTS: A median of 756 radiation episodes per month was captured for a total of 9,283 unique episodes captured in the first full year of implementation. The most common notes were for on-treatment visits (29,913) and simulations (13,220). Stage was captured for 92.2% of Brocade episodes (8,513 of 9,236) versus 29.7% of courses pre-Brocade (3,025 of 10,170; P < .001). Quality assurance was documented for 96.3% of completed courses (7,601 of 7,892). The most common grade ≥1 toxicities were pain (10,031), fatigue (7,490), and dermatitis (6,172). Brocade implementation was associated with a reduction in off-hours documentation and increase in the proportion of documentation created between 8:00 am and 12:00 pm. CONCLUSION: Brocade is a reliable Web-based EDC tool that improves clinical documentation without detracting from clinical workflow. Moreover, Brocade has the advantage of capturing data in a structured manner that facilitates real-time analytics and outcome reporting.

Adoption of Radiation Technology Among Privately Insured Nonelderly Patients With Cancer in the United States, 2008 to 2014: A Claims-Based Analysis.

Despite enthusiasm for advanced radiation technologies, understanding of their adoption in recent years is limited. The aim of this study was to elucidate utilization trends of conventional radiation, intensity-modulated radiotherapy (IMRT), brachytherapy, proton radiotherapy, stereotactic body radiotherapy (SBRT), and stereotactic radiosurgery (SRS) using a large convenience sample of irradiated patients with cancer identified from private insurance claims in the United States. The unit of analysis was a claim corresponding to a fraction of delivered radiotherapy from 2008 to 2014. Each claim was assigned a disease site on the basis of the diagnosis code and a radiation technology on the basis of the procedure code. In 2014, conventional radiation and IMRT constituted 56% and 39% of all radiation treatment claims, respectively, while brachytherapy constituted 2%, proton radiotherapy 1%, SBRT 1%, and SRS <1%. Compared with the first quarter of 2008, the proportional contribution of conventional radiation and brachytherapy to all radiation claims each decreased by 16% in the fourth quarter of 2014. In contrast, proportional contribution increased by 32% for IMRT, 83% for proton radiotherapy, 124% for SRS, and 309% for SBRT. Prostate cancer constituted 60% of all proton claims in 2008 but declined to 37% by 2014. SBRT was used to treat a variety of disease sites, most commonly primary lung (25%), prostate (12%), secondary bone (9%), and secondary lung (9%), in 2014. In this claims-based analysis of younger patients with private insurance, conventional radiation and IMRT were the most commonly used technologies from 2008 to 2014, while SBRT showed the most robust growth over the study period.

Insurance Status and Racial Disparities in Cancer-Specific Mortality in the United States: A Population-Based Analysis.

Background: Cancer-specific mortality (CSM) is known to be higher among blacks and lower among Hispanics compared with whites. Private insurance confers CSM benefit, but few studies have examined the relationship between insurance status and racial disparities. We sought to determine differences in CSM between races within insurance subgroups.Methods: A population-based cohort of 577,716 patients age 18 to 64 years diagnosed with one of the 10 solid malignancies causing the greatest mortality over 2007 to 2012 were obtained from Surveillance, Epidemiology, and End Results. A Cox proportional hazards model for CSM was constructed to adjust for known prognostic factors, and interaction analysis between race and insurance was performed to generate stratum-specific HRs.Results: Blacks had similar CSM to whites among the uninsured [HR = 1.01; 95% confidence interval (CI), 0.96-1.05], but higher CSM among the Medicaid (HR = 1.04; 95% CI, 0.01-1.07) and non-Medicaid (HR = 1.14; 95% CI, 1.12-1.16) strata. Hispanics had lower CSM compared with whites among uninsured (HR = 0.80; 95% CI, 0.76-0.85) and Medicaid (HR = 0.88; 95% CI, 0.85-0.91) patients, but there was no difference among non-Medicaid patients (HR = 0.99; 95% CI, 0.97-1.01). Asians had lower CSM compared with whites among all insurance types: uninsured (HR = 0.80; 95% CI, 0.76-0.85), Medicaid (HR = 0.81; 95% CI, 0.77-0.85), and non-Medicaid (HR = 0.85; 95% CI, 0.83-0.87).Conclusions: The disparity between blacks and whites was largest, and the advantage of Hispanic race was absent within the non-Medicaid subgroup.Impact: These findings suggest that whites derive greater benefit from private insurance than blacks and Hispanics. Further research is necessary to determine why this differential exists and how disparities can be improved. Cancer Epidemiol Biomarkers Prev; 26(6); 869-75. ©2017 AACR.

Internal validation of the prognostic index for spine metastasis (PRISM) for stratifying survival in patients treated with spinal stereotactic radiosurgery.

PURPOSE: We sought to validate the Prognostic Index for Spinal Metastases (PRISM), a scoring system that stratifies patients into subgroups by overall survival.Methods and materials: The PRISM was previously created from multivariate Cox regression with patients enrolled in prospective single institution trials of stereotactic spine radiosurgery (SSRS) for spinal metastasis. We assess model calibration and discrimination within a validation cohort of patients treated off-trial with SSRS for metastatic disease at the same institution. RESULTS: The training and validation cohorts consisted of 205 and 249 patients respectively. Similar survival trends were shown in the 4 PRISM. Survival was significantly different between PRISM subgroups (P<0.0001). C-index for the validation cohort was 0.68 after stratification into subgroups. CONCLUSIONS: We internally validated the PRISM with patients treated off-protocol, demonstrating that it can distinguish subgroups by survival, which will be useful for individualizing treatment of spinal metastases and stratifying patients for clinical trials.

The Radiation Oncology Job Market: The Economics and Policy of Workforce Regulation.

Examinations of the US radiation oncology workforce offer inconsistent conclusions, but recent data raise significant concerns about an oversupply of physicians. Despite these concerns, residency slots continue to expand at an unprecedented pace. Employed radiation oncologists and professional corporations with weak contracts or loose ties to hospital administrators would be expected to suffer the greatest harm from an oversupply. The reduced cost of labor, however, would be expected to increase profitability for equipment owners, technology vendors, and entrenched professional groups. Policymakers must recognize that the number of practicing radiation oncologists is a poor surrogate for clinical capacity. There is likely to be significant opportunity to augment capacity without increasing the number of radiation oncologists by improving clinic efficiency and offering targeted incentives for geographic redistribution. Payment policy changes significantly threaten radiation oncologists' income, which may encourage physicians to care for greater patient loads, thereby obviating more personnel. Furthermore, the implementation of alternative payment models such as Medicare's Oncology Care Model threatens to decrease both the utilization and price of radiation therapy by turning referring providers into cost-conscious consumers. Medicare funds the vast majority of graduate medical education, but the extent to which the expansion in radiation oncology residency slots has been externally funded is unclear. Excess physician capacity carries a significant risk of harm to society by suboptimally allocating intellectual resources and creating comparative shortages in other, more needed disciplines. There are practical concerns associated with a market-based solution in which medical students self-regulate according to job availability, but antitrust law would likely forbid collaborative self-regulation that purports to restrict supply. Because Congress is unlikely to create one central body to govern residency controls for all specialties, we recommend better reporting of program-specific employment metrics and careful, intellectually honest re-evaluation of existing Accreditation Council for Graduate Medical Education accreditation standards.

Supply and Demand for Radiation Oncology in the United States: Updated Projections for 2015 to 2025.

PURPOSE: Prior studies have forecasted demand for radiation therapy to grow 10 times faster than the supply between 2010 and 2020. We updated these projections for 2015 to 2025 to determine whether this imbalance persists and to assess the accuracy of prior projections. METHODS AND MATERIALS: The demand for radiation therapy between 2015 and 2025 was estimated by combining current radiation utilization rates determined by the Surveillance, Epidemiology, and End Results data with population projections provided by the US Census Bureau. The supply of radiation oncologists was forecast by using workforce demographics and full-time equivalent (FTE) status provided by the American Society for Radiation Oncology (ASTRO), current resident class sizes, and expected survival per life tables from the US Centers for Disease Control. RESULTS: Between 2015 and 2025, the annual total number of patients receiving radiation therapy during their initial treatment course is expected to increase by 19%, from 490,000 to 580,000. Assuming a graduating resident class size of 200, the number of FTE physicians is expected to increase by 27%, from 3903 to 4965. In comparison with prior projections, the new projected demand for radiation therapy in 2020 dropped by 24,000 cases (a 4% relative decline). This decrease is attributable to an overall reduction in the use of radiation to treat cancer, from 28% of all newly diagnosed cancers in the prior projections down to 26% for the new projections. By contrast, the new projected supply of radiation oncologists in 2020 increased by 275 FTEs in comparison with the prior projection for 2020 (a 7% relative increase), attributable to rising residency class sizes. CONCLUSION: The supply of radiation oncologists is expected to grow more quickly than the demand for radiation therapy from 2015 to 2025. Further research is needed to determine whether this is an appropriate correction or will result in excess capacity.

Single-fraction versus multifraction spinal stereotactic radiosurgery for spinal metastases from renal cell carcinoma: secondary analysis of Phase I/II trials.

OBJECTIVE The objective of this study was to compare fractionation schemes and outcomes of patients with renal cell carcinoma (RCC) treated in institutional prospective spinal stereotactic radiosurgery (SSRS) trials who did not previously undergo radiation treatment at the site of the SSRS. METHODS Patients enrolled in 2 separate institutional prospective protocols and treated with SSRS between 2002 and 2011 were included. A secondary analysis was performed on patients with previously nonirradiated RCC spinal metastases treated with either single-fraction (SF) or multifraction (MF) SSRS. RESULTS SSRS was performed in 47 spinal sites on 43 patients. The median age of the patients was 62 years (range 38-75 years). The most common histological subtype was clear cell (n = 30). Fifteen sites underwent surgery prior to the SSRS, with laminectomy the most common procedure performed (n = 10). All SF SSRS was delivered to a dose of 24 Gy (n = 21) while MF regiments were either 27 Gy in 3 fractions (n = 20) or 30 Gy in 5 fractions (n = 6). The median overall survival duration for the entire cohort was 22.8 months. The median local control (LC) for the entire cohort was 80.6 months with 1-year and 2-year actuarial LC rates of 82% and 68%, respectively. Single-fraction SSRS correlated with improved 1- and 2-year actuarial LC relative to MF SSRS (95% vs 71% and 86% vs 55%, respectively; p = 0.009). On competing risk analysis, SF SSRS showed superior LC to MF SSRS (subhazard ratio [SHR] 6.57, p = 0.014). On multivariate analysis for LC with tumor volume (p = 0.272), number of treated levels (p = 0.819), gross tumor volume (GTV) coverage (p = 0.225), and GTV minimum point dose (p = 0.97) as covariates, MF SSRS remained inferior to SF SSRS (SHR 5.26, p = 0.033) CONCLUSIONS SSRS offers durable LC for spinal metastases from RCC. Single-fraction SSRS is associated with improved LC over MF SSRS for previously nonirradiated RCC spinal metastases.

Implementing a Real-Time Electronic Data Capture System to Improve Clinical Documentation in Radiation Oncology.

PURPOSE: Electronic health records (EHRs) often store information as unstructured text, whereas electronic data capture (EDC) using structured fields is common in clinical trials. We implemented a web-based EDC system for routine clinical care, and describe our experience piloting this system for breast cancer patients receiving radiation therapy. METHODS: Our institution uses dictation for clinical documentation in a centralized EHR; a separate radiation therapy-specific record-and-verify system contains prescriptions, schedules, and treatment documentation. The implemented EDC system collects patient, tumor, and treatment characteristics using structured data fields and merges it with data from the radiation therapy system to generate template-based notes in the EHR. Mean times to create notes using dictation versus EDC were compared. Users were surveyed about their experience. Acute toxicities were captured using the EDC system, and reported. RESULTS: The EDC system has been used by 25 providers for 1,296 patients. In the most recent month, 978 clinical notes were generated. The average clinician documentation time over a typical course of radiation was reduced from 22.4 minutes per patient with dictation, to 7.1 minutes with EDC. The user survey response rate was 100%, with 92% of respondents being either satisfied or very satisfied with their experience. The worst acute toxicities were mostly grade 1 (51%) or grade 2 (43%), with rare grade 3 (3%) events. CONCLUSIONS: We implemented an EDC system for routine clinical use in the breast radiation therapy service that resulted in significant time-savings for clinical documentation and prospective population of a database to facilitate outcomes reporting.

Creation of a Prognostic Index for Spine Metastasis to Stratify Survival in Patients Treated With Spinal Stereotactic Radiosurgery: Secondary Analysis of Mature Prospective Trials.

PURPOSE: There exists uncertainty in the prognosis of patients following spinal metastasis treatment. We sought to create a scoring system that stratifies patients based on overall survival. METHODS AND MATERIALS: Patients enrolled in 2 prospective trials investigating stereotactic spine radiation surgery (SSRS) for spinal metastasis with ≥ 3-year follow-up were analyzed. A multivariate Cox regression model was used to create a survival model. Pretreatment variables included were race, sex, age, performance status, tumor histology, extent of vertebrae involvement, previous therapy at the SSRS site, disease burden, and timing of diagnosis and metastasis. Four survival groups were generated based on the model-derived survival score. RESULTS: Median follow-up in the 206 patients included in this analysis was 70 months (range: 37-133 months). Seven variables were selected: female sex (hazard ratio [HR] = 0.7, P=.02), Karnofsky performance score (HR = 0.8 per 10-point increase above 60, P = .007), previous surgery at the SSRS site (HR = 0.7, P=.02), previous radiation at the SSRS site (HR = 1.8, P=.001), the SSRS site as the only site of metastatic disease (HR = 0.5, P=.01), number of organ systems involved outside of bone (HR = 1.4 per involved system, P<.001), and >5 year interval from initial diagnosis to detection of spine metastasis (HR = 0.5, P < .001). The median survival among all patients was 25.5 months and was significantly different among survival groups (in group 1 [excellent prognosis], median survival was not reached; group 2 reached 32.4 months; group 3 reached 22.2 months; and group 4 [poor prognosis] reached 9.1 months; P < .001). Pretreatment symptom burden was significantly higher in the patient group with poor survival than in the group with excellent survival (all metrics, P < .05). CONCLUSIONS: We developed the prognostic index for spinal metastases (PRISM) model, a new model that identified patient subgroups with poor and excellent prognoses.

Prognostic factors and patterns of relapse in ewing sarcoma patients treated with chemotherapy and r0 resection.

PURPOSE: To identify prognostic factors and patterns of relapse for patients with Ewing sarcoma who underwent chemotherapy and R0 resection without radiation therapy (RT). METHODS AND MATERIALS: We reviewed the medical records of patients who underwent surgical resection at our institution between 2000 and 2013 for an initial diagnosis of Ewing sarcoma. The associations of demographic and clinical factors with local control (LC) and patient outcome were determined by Cox regression. Time to events was measured from the time of surgery. Survival curves were estimated by the Kaplan-Meier method and compared by the log-rank test. RESULTS: A total of 66 patients (median age 19 years, range 4-55 years) met the study criteria. The median follow-up was 5.6 years for living patients. In 43 patients (65%) for whom imaging studies were available, the median tumor volume reduction was 73%, and at least partial response by Response Evaluation Criteria in Solid Tumors was achieved in 17 patients (40%). At 5 years, LC was 78%, progression-free survival (PFS) was 59%, and overall survival (OS) was 65%. Poor histologic response (necrosis ≤95%) was an independent predictor of LC (hazard ratio [HR] 6.8, P=.004), PFS (HR 5.2, P=.008), and OS (HR 5.0, P=.008). Metastasis on presentation was also an independent predictor of LC (HR 6.3, P=.011), PFS (HR 6.8, P=.002), and OS (HR 6.7, P=.002). Radiologic partial response was a predictor of PFS (HR 0.26, P=.012), and postchemotherapy tumor volume was associated with OS (HR 1.06, P=.015). All deaths were preceded by distant relapse. Of the 8 initial local-only relapses, 5 (63%) were soon followed by distant relapse. Predictors of poor postrecurrence survival were time to recurrence <1 year (HR 11.5, P=.002) and simultaneous local and distant relapse (HR 16.8, P=.001). CONCLUSIONS: Histologic and radiologic response to chemotherapy were independent predictors of outcome. Additional study is needed to determine the role of adjuvant radiation therapy for patients who have poor histologic response after R0 resection.

Early experience with intensity modulated proton therapy for lung-intact mesothelioma: A case series.

PURPOSE: The purpose of this study was to describe our experience implementing intensity modulated proton therapy (IMPT) for lung-intact malignant pleural mesothelioma (MPM), including patient selection, treatment planning, dose verification, and process optimization. METHODS AND MATERIALS: Seven patients with epithelioid MPM were reviewed; 6 underwent pleurectomy, whereas 1 had biopsy alone. Four patients received IMPT and 3 received intensity modulated radiation therapy. Treatment plans for the other modality were created for dosimetric comparisons. Quality assurance processes included dose verification and robustness analysis. Image-guided setup was performed with the first isocenter, and couch shifts were applied to reposition to the second isocenter. RESULTS: Treatment with IMPT was well tolerated and completed without breaks. IMPT plans were designed with 2 isocenters, 4 beams, and ≤64 energy layers per beam. Dose verification processes were completed in 3 hours. Total daily treatment time was approximately 45 minutes (20 minutes for setup and 25 minutes for delivery). IMPT produced lower mean doses to the contralateral lung, heart, esophagus, liver, and ipsilateral kidney, with increased contralateral lung sparing when mediastinal boost was required for nodal disease. CONCLUSIONS: Our initial experience showed that IMPT was feasible for routine care of patients with lung-intact MPM.

Hemithoracic intensity modulated radiation therapy after pleurectomy/decortication for malignant pleural mesothelioma: toxicity, patterns of failure, and a matched survival analysis.

PURPOSE: To investigate safety, efficacy, and recurrence after hemithoracic intensity modulated radiation therapy after pleurectomy/decortication (PD-IMRT) and after extrapleural pneumonectomy (EPP-IMRT). METHODS AND MATERIALS: In 2009-2013, 24 patients with mesothelioma underwent PD-IMRT to the involved hemithorax to a dose of 45 Gy, with an optional integrated boost; 22 also received chemotherapy. Toxicity was scored with the Common Terminology Criteria for Adverse Events v4.0. Pulmonary function was compared at baseline, after surgery, and after IMRT. Kaplan-Meier analysis was used to calculate overall survival (OS), progression-free survival (PFS), time to locoregional failure, and time to distant metastasis. Failures were in-field, marginal, or out of field. Outcomes were compared with those of 24 patients, matched for age, nodal status, performance status, and chemotherapy, who had received EPP-IMRT. RESULTS: Median follow-up time was 12.2 months. Grade 3 toxicity rates were 8% skin and 8% pulmonary. Pulmonary function declined from baseline to after surgery (by 21% for forced vital capacity, 16% for forced expiratory volume in 1 second, and 19% for lung diffusion of carbon monoxide [P for all = .01]) and declined still further after IMRT (by 31% for forced vital capacity [P=.02], 25% for forced expiratory volume in 1 second [P=.01], and 30% for lung diffusion of carbon monoxide [P=.01]). The OS and PFS rates were 76% and 67%, respectively, at 1 year and 56% and 34% at 2 years. Median OS (28.4 vs 14.2 months, P=.04) and median PFS (16.4 vs 8.2 months, P=.01) favored PD-IMRT versus EPP-IMRT. No differences were found in grade 4-5 toxicity (0 of 24 vs 3 of 24, P=.23), median time to locoregional failure (18.7 months vs not reached, P not calculable), or median time to distant metastasis (18.8 vs 11.8 months, P=.12). CONCLUSIONS: Hemithoracic intensity modulated radiation therapy after pleurectomy/decortication produced little high-grade toxicity but led to progressive declines in pulmonary function; OS and PFS were better in PD-IMRT compared with EPP-IMRT.

Prospective exploratory analysis of cardiac biomarkers and electrocardiogram abnormalities in patients receiving thoracic radiation therapy with high-dose heart exposure.

INTRODUCTION: Acute effects of incidental cardiac irradiation in patients treated for thoracic cancer are not well characterized. We evaluated longitudinal changes in cardiac biomarkers for patients undergoing conformal radiation therapy (RT) with thoracic malignancies with high-dose cardiac exposure. METHODS: Twenty-five patients enrolled in a prospective trial (February 2009-December 2012) received more than or equal to 45 Gy to the thorax, with pretreatment estimates of more than or equal to 20 Gy to the heart. Chemotherapy was allowed except for doxorubicin or fluorouracil. Electrocardiographic (ECG), troponin-I (TnI), and brain natriuretic peptide (BNP) measurements were obtained before RT, within 24 hours of the first fraction, at the end of RT, and at first follow-up (1-2 months). These biomarkers were quantified at specific times and changes from baseline were evaluated with paired t tests. RESULTS: The median heart dose was 25.9 Gy (range 10.1-35.1 Gy). After the first RT fraction, no changes were noted in ECG or median TnI or BNP levels; at the end of RT, two patients had elevated TnI and BNP, but neither difference was statistically significant. At first follow-up, TnI had returned to normal but the median BNP remained elevated (p = 0.042). BNP did not increase over time in the 18 patients who received only RT. Twelve patients experienced acute ECG changes during RT, which resolved in seven patients by the next measurement. No patients experienced clinically significant RT-related events. CONCLUSION: Increases in BNP and ECG changes were observed during high doses of radiation to the heart. The findings of this pilot study warrant further investigation and validation.