Kim L Light

Duke University, Durham, North Carolina, United States

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Publications (45)167.11 Total impact

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    ABSTRACT: Purpose/objective: While our department is heavily invested in computer-based treatment planning, we historically relied on paper-based charts for management of Radiation Oncology patients. In early 2009, we initiated the process of conversion to an electronic medical record (EMR) eliminating the need for paper charts. Key goals included the ability to readily access information wherever and whenever needed, without compromising safety, treatment quality, confidentiality, or productivity. Methodology: In February, 2009, we formed a multi-disciplinary team of Radiation Oncology physicians, nurses, therapists, administrators, physicists/dosimetrists, and information technology (IT) specialists, along with staff from the Duke Health System IT department. The team identified all existing processes and associated information/reports, established the framework for the EMR system and generated, tested and implemented specific EMR processes. Results: Two broad classes of information were identified: information which must be readily accessed by anyone in the health system versus that used solely within the Radiation Oncology department. Examples of the former are consultation reports, weekly treatment check notes, and treatment summaries; the latter includes treatment plans, daily therapy records, and quality assurance reports. To manage the former, we utilized the enterprise-wide system, which required an intensive effort to design and implement procedures to export information from Radiation Oncology into that system. To manage "Radiation Oncology" data, we used our existing system (ARIA, Varian Medical Systems.) The ability to access both systems simultaneously from a single workstation (WS) was essential, requiring new WS and modified software. As of January, 2010, all new treatments were managed solely with an EMR. We find that an EMR makes information more widely accessible and does not compromise patient safety, treatment quality, or confidentiality. However, compared to paper charts, time required by clinicians to access/enter patient information has substantially increased. While productivity is improving with experience, substantial growth will require better integration of the system components, decreased access times, and improved user interfaces. $127K was spent on new hardware and software; elimination of paper yields projected savings of $21K/year. One year after conversion to an EMR, more than 90% of department staff favored the EMR over the previous paper charts. Conclusion: Successful implementation of a Radiation Oncology EMR required not only the effort and commitment of all functions of the department, but support from senior health system management, corporate IT, and vendors. Realization of the full benefits of an EMR will require experience, faster/better integrated software, and continual improvement in underlying clinical processes.
    Frontiers in Oncology 04/2013; 3:69. DOI:10.3389/fonc.2013.00069
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    ABSTRACT: Several series evaluating external-beam partial breast irradiation (PBI) have linked negative cosmetic outcomes to large normal tissue treatment volumes. We compared patients treated with PBI whose treatment plans included only photons to those whose plans incorporated electrons. Twenty-seven patients were identified: median age 67 years, pT1 82%, pN0 56%, margin negative 100%. All received 38.5 Gy using 3-5 noncoplanar photon beams (6-15X). Electrons (9-20 MeV) were included in 59%. Median follow-up was 22 months. Ninety percent experienced good/excellent cosmetic outcomes. Two patients had fair cosmesis, and both were treated with a mixed photon/electron approach. Median conformity index for photon-only treatment plans was 1.7 (range, 0.9-2.0) and for photon/electron plans, 1.0 (0.3-1.4). Median percent ipsilateral breast volume receiving 100% and 50% of prescription dose was 19 and 50 for photon-only plans vs. 10 and 38 for photon/electron plans (p < 0.05). Median percent target volume receiving 100% and 95% of prescription dose was 93 and 98 for photon-only plans vs. 75 and 94 for photon/electron plans (p < 0.05). A mixed photon/electron, noncoplanar technique decreases the volume of treated normal breast tissue at the cost of slightly decreased tumor bed coverage. Further study is needed to determine whether this results in a more favorable therapeutic ratio than photon-only approaches.
    Medical dosimetry: official journal of the American Association of Medical Dosimetrists 03/2011; 36(4):423-8. DOI:10.1016/j.meddos.2010.10.004 · 0.76 Impact Factor

  • Fuel and Energy Abstracts 11/2010; 78(3). DOI:10.1016/j.ijrobp.2010.07.1154
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    ABSTRACT: Traditional treatment beams for non-small-cell lung cancer are limited to the axial plane. For many tumor geometries, non-axial orientations appear to reduce the dose to normal tissues (e.g. heart, liver). We hypothesize that non-axial beams provide a significant reduction in incidental irradiation of the heart and liver, while maintaining adequate target coverage. CT scans of twenty-four patients with lower lobe lung cancers were studied. For each patient, an opposed oblique axial beam pair and a competing non-axial opposed oblique pair were generated, both off-cord. The competing plans delivered comparable doses/margins to the GTV. DVHs and integral doses were computed for all structures of interest for the two competing plans. The integral dose was compared for axial and non-axial beams for each contoured organ using a paired t-test. Dose to the heart was significantly lower for the non-axial plans ( p = .0001). For 20/24 patients, the integral heart dose was reduced by using non-axial beams. In those patients with tumors located in the inferior right lower lobe, a lower dose to the liver was achieved when non-axial beams were used. There were no meaningful differences in dose to the GTV, lungs, or skin between axial and non-axial beams. Non-axial beams can reduce the dose to the heart and liver in patients with lower lobe lung cancers. Non-axial beams may be clinically beneficial in these patients and should be considered as an option during planning.
    Journal of Applied Clinical Medical Physics 01/2010; 11(1):3010. · 1.17 Impact Factor

  • Fuel and Energy Abstracts 11/2009; 75(3). DOI:10.1016/j.ijrobp.2009.07.481

  • Fuel and Energy Abstracts 11/2009; 75(3). DOI:10.1016/j.ijrobp.2009.07.443
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    ABSTRACT: To assess the association between radiotherapy (RT)-induced changes in computed tomography (CT)-defined lung tissue density and pulmonary function tests (PFTs). Patients undergoing incidental partial lung RT were prospectively assessed for global (PFTs) and regional (CT and single photon emission CT [SPECT]) lung function before and, serially, after RT. The percent reductions in the PFT and the average changes in lung density were compared (Pearson correlations) in the overall group and subgroups stratified according to various clinical factors. Comparisons were also made between the CT- and SPECT-based computations using the Mann-Whitney U test. Between 1991 and 2004, 343 patients were enrolled in this study. Of these, 111 patients had a total of 203 concurrent post-RT evaluations of changes in lung density and PFTs available for the analyses, and 81 patients had a total of 141 concurrent post-RT SPECT images. The average increases in lung density were related to the percent reductions in the PFTs, albeit with modest correlation coefficients (range, 0.20-0.43). The analyses also indicated that the association between lung density and PFT changes is essentially equivalent to the corresponding association with SPECT-defined lung perfusion. We found a weak quantitative association between the degree of increase in lung density as defined by CT and the percent reduction in the PFTs.
    International journal of radiation oncology, biology, physics 07/2009; 74(3):781-9. DOI:10.1016/j.ijrobp.2008.08.053 · 4.26 Impact Factor
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    ABSTRACT: To study the temporal nature of regional lung density changes and to assess whether the dose-dependent nature of these changes is associated with patient- and treatment-associated factors. Between 1991 and 2004, 118 patients with interpretable pre- and post-radiation therapy (RT) chest computed tomography (CT) scans were evaluated. Changes in regional lung density were related to regional dose to define a dose-response curve (DRC) for RT-induced lung injury using three-dimensional planning tools and image fusion. Multiple post-RT follow-up CT scans were evaluated by fitting linear-quadratic models of density changes on dose with time as the covariate. Various patient- and treatment-related factors were examined as well. There was a dose-dependent increase in regional lung density at nearly all post-RT follow-up intervals. The population volume-weighted changes evolved over the initial 6-month period after RT and reached a plateau thereafter (p < 0.001). On univariate analysis, patient age greater than 65 years (p = 0.003) and/or the use of pre-RT surgery (p < 0.001) were associated with significantly greater changes in CT density at both 6 and 12 months after RT, but the magnitude of this effect was modest. There appears to be a temporal nature for the dose-dependent increases in lung density. Nondosimetric clinical factors tend to have no, or a modest, impact on these changes.
    International journal of radiation oncology, biology, physics 04/2009; 76(1):116-22. DOI:10.1016/j.ijrobp.2009.01.025 · 4.26 Impact Factor

  • International Journal of Radiation OncologyBiologyPhysics 09/2008; 72(1). DOI:10.1016/j.ijrobp.2008.06.999 · 4.26 Impact Factor
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    ABSTRACT: A prospective study was performed to formally relate dose-dependent radiologically defined changes in normal brain induced by radiotherapy (RT) to neurocognitive dysfunction in subjects with primary brain tumors. Adult patients receiving three-dimensional RT for central nervous system (CNS) tumors were enrolled. Positron emission tomography (PET) scanning and neuropsychological testing were performed before RT and 3 weeks and 6 months after treatment. Analyses were performed for correlations between changes in 2-deoxy-2-[(18)F]-fluoro-d-glucose (FDG)-PET (metabolism), (15)O-PET (relative blood flow), regional radiation dose, follow-up time, and neuropsychological test scores. Eleven subjects were enrolled and 6 completed follow-up studies. The PET data showed reduced FDG uptake, with average decreases of 2-6% in regions of the brain receiving greater than 40 Gy at 3 weeks' and 6 months' follow-up. The (15)O-H(2)O PET showed increases (<10%) at 3 weeks in relative regional blood flow in brain receiving greater than 30 Gy, but less at the 6-month follow-up studies. There were significant correlations between decreases in FDG uptake and increased scores from the Symptom Checklist-90-R, with an average increase in T score of 2 (p < 0.0001). The Wisconsin Card Sorting Test showed a significant correlation of decreased FDG uptake with increased errors and perseveration in test performance, with an average decrease in T score of 11 (p = 0.037). A dose-dependent response of CNS tissue was detected using FDG PET in this small number of patients. Decreases in CNS metabolism correlated with decreased performance on neuropsychological tests for problem solving, cognitive flexibility, and global measures of psychopathology. Additional research is needed to verify and define these findings.
    International journal of radiation oncology, biology, physics 09/2008; 73(4):1082-7. DOI:10.1016/j.ijrobp.2008.05.061 · 4.26 Impact Factor

  • International Journal of Radiation OncologyBiologyPhysics 09/2008; 72(1). DOI:10.1016/j.ijrobp.2008.06.464 · 4.26 Impact Factor
  • S. Yoo · J. Boyd · S. Das · F. Yin · E. Jones · K. Light · L. Marks ·

    International Journal of Radiation OncologyBiologyPhysics 09/2008; 72(1). DOI:10.1016/j.ijrobp.2008.06.050 · 4.26 Impact Factor
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    ABSTRACT: To assess the impact of new technologies on deviation rates in radiation therapy (RT). Treatment delivery deviations in RT were prospectively monitored during a time of technology upgrade. In January 2003, our department had three accelerators, none with "modern" technologies (e.g., without multileaf collimators [MLC]). In 2003 to 2004, we upgraded to five new accelerators, four with MLC, and associated advanced capabilities. The deviation rates among patients treated on "high-technology" versus "low-technology" machines (defined as those with vs. without MLC) were compared over time using the two-tailed Fisher's exact test. In 2003, there was no significant difference between the deviation rate in the "high-technology" versus "low-technology" groups (0.16% vs. 0.11%, p = 0.45). In 2005 to 2006, the deviation rate for the "high-technology" groups was lower than the "low-technology" (0.083% vs. 0.21%, p = 0.009). This difference was caused by a decline in deviations on the "high-technology" machines over time (p = 0.053), as well as an unexpected trend toward an increase in deviations over time on the "low-technology" machines (p = 0.15). Advances in RT delivery systems appear to reduce the rate of treatment deviations. Deviation rates on "high-technology" machines with MLC decline over time, suggesting a learning curve after the introduction of new technologies. Associated with the adoption of "high-technology" was an unexpected increase in the deviation rate with "low-technology" approaches, which may reflect an over-reliance on tools inherent to "high-technology" machines. With the introduction of new technologies, continued diligence is needed to ensure that staff remain proficient with "low-technology" approaches.
    International Journal of Radiation OncologyBiologyPhysics 01/2008; 69(5):1579-86. DOI:10.1016/j.ijrobp.2007.08.017 · 4.26 Impact Factor

  • International Journal of Radiation OncologyBiologyPhysics 11/2007; 69(3). DOI:10.1016/j.ijrobp.2007.07.283 · 4.26 Impact Factor

  • International Journal of Radiation OncologyBiologyPhysics 11/2007; 69(3). DOI:10.1016/j.ijrobp.2007.07.354 · 4.26 Impact Factor
  • S. Yoo · S. Das · S. Kim · B. Koontz · W. Lee · K. Light · F. Yin ·

    Medical Physics 06/2007; 34(6). DOI:10.1118/1.2760573 · 2.64 Impact Factor
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    ABSTRACT: The aim of this study was to assess the impact of patient-specific factors, left ventricle (LV) volume, and treatment set-up errors on the rate of perfusion defects 6 to 60 months post-radiation therapy (RT) in patients receiving tangential RT for left-sided breast cancer. Between 1998 and 2005, a total of 153 patients were enrolled onto an institutional review board-approved prospective study and had pre- and serial post-RT (6-60 months) cardiac perfusion scans to assess for perfusion defects. Of the patients, 108 had normal pre-RT perfusion scans and available follow-up data. The impact of patient-specific factors on the rate of perfusion defects was assessed at various time points using univariate and multivariate analysis. The impact of set-up errors on the rate of perfusion defects was also analyzed using a one-tailed Fisher's Exact test. Consistent with our prior results, the volume of LV in the RT field was the most significant predictor of perfusion defects on both univariate (p = 0.0005 to 0.0058) and multivariate analysis (p = 0.0026 to 0.0029). Body mass index (BMI) was the only significant patient-specific factor on both univariate (p = 0.0005 to 0.022) and multivariate analysis (p = 0.0091 to 0.05). In patients with very small volumes of LV in the planned RT fields, the rate of perfusion defects was significantly higher when the fields set-up "too deep" (83% vs. 30%, p = 0.059). The frequency of deep set-up errors was significantly higher among patients with BMI > or =25 kg/m2 compared with patients of normal weight (47% vs. 28%, p = 0.068). BMI > or =25 kg/m2 may be a significant risk factor for cardiac toxicity after RT for left-sided breast cancer, possibly because of more frequent deep set-up errors resulting in the inclusion of additional heart in the RT fields. Further study is necessary to better understand the impact of patient-specific factors and set-up errors on the development of RT-induced perfusion defects.
    International journal of radiation oncology, biology, physics 12/2006; 66(4):1125-34. DOI:10.1016/j.ijrobp.2006.06.025 · 4.26 Impact Factor
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    ABSTRACT: The purpose of the study was to reassess the utility of transforming growth factor-beta-1 (TGF-beta1) together with dosimetric and tumor parameters as a predictor for radiation pneumonitis (RP). Of the 121 patients studied, 32 (26.4%) developed grade > or =1 RP, and 27 (22.3%) developed grade > or =2 RP. For the endpoint of grade > or =1 RP, those with V30>30% and an end-RT/baseline TGF-beta1 ratio> or =1 had a significantly higher incidence of RP than did those with V30>30% and an end-RT/baseline TGF-beta1 ratio<1. For most other patient groups, there were no clear associations between TGF-beta1 values and rates of RP. These findings suggest that TGF-beta1 is generally not predictive for RP except for the group of patients with a high V30.
    Cytokine 09/2006; 35(3-4):186-92. DOI:10.1016/j.cyto.2006.07.021 · 2.66 Impact Factor
  • Chris R Kelsey · Kim L Light · Lawrence B Marks ·
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    ABSTRACT: To analyze local-regional patterns of failure after surgical resection of non-small-cell lung cancer (NSCLC). This retrospective analysis included 61 patients who underwent resection of NSCLC at Duke University Medical Center. Inclusion into the study required the following: margin-negative resection, no neoadjuvant/adjuvant radiation therapy (RT), first recurrence involving a local-regional site, and imaging studies available for review. Sites of intrathoracic disease recurrence were documented. Diagrams were constructed that illustrated sites of failure on the basis of lobe of primary tumor. Failure rates were compared by application of a two-tailed Fisher's exact test. All patients had CT imaging for review, and 54% also had PET imaging. The median number of local-regional recurrent sites was two (range, 1-6). For all patients, the most common site of failure was the bronchial stump/staple line (44%), which was present more often in those who had a wedge resection than in those who had a more radical procedure (79% vs. 34%, p=0.005). Patients with initial nodal involvement (pN1-2) were not more likely to have involvement of the mediastinum than were patients with pN0 disease (64% vs. 72%, p=0.72), but were more likely to have involvement of the supraclavicular fossa (27% vs. 4%, p=0.04). Mediastinal involvement, without overt evidence of hilar involvement, occurred in 59% of patients. Left-sided tumors tended to involve the contralateral mediastinum more frequently than did right-sided tumors. Patterns of failure after resection are diagrammed and follow a fairly predictable pattern on the basis of involved lobe. These data may help clinicians construct postoperative RT volumes that are smaller than ones traditionally utilized, which may improve the therapeutic ratio.
    International Journal of Radiation OncologyBiologyPhysics 08/2006; 65(4):1097-105. DOI:10.1016/j.ijrobp.2006.02.007 · 4.26 Impact Factor
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    ABSTRACT: Tangential radiotherapy for left-sided breast cancer may be cardiotoxic. Shaping the field with a heart block reduces cardiac exposure but may under-dose the breast and/or chest wall. We compared the incidence and location of local recurrences in patients irradiated with and without a heart block. Between 1994 and 1998, 180 patients irradiated to the left breast and/or chest wall were retrospectively reviewed. The local recurrence rates in patients treated with and without a heart block were compared using a 2-tailed Fisher exact test. An in-depth dosimetric analysis was performed in 23 patients to assess the percentage of breast tissue under-dosed by inclusion of the heart block. Overall, the local recurrence rates in patients with or without a heart block were similar. In postlumpectomy patients with inferiorly located tumors, the rates of local recurrence with and without a heart block were 2 of 6 patients versus 0 of 19 patients, respectively. In the dosimetric analysis, the average percentage of breast tissue under-dosed by the inclusion of a heart block was 2.8% (range, 0%-11%). A heart block is a reasonable method to limit cardiac dose but should be used cautiously following a lumpectomy in patients with inferiorly located tumors. Additional study with larger numbers of patients is warranted.
    The Cancer Journal 07/2006; 12(4):309-17. DOI:10.1097/00130404-200607000-00010 · 4.24 Impact Factor