Virtual Library

Start Your Search

Changhui Yu



Author of

  • +

    EP1.17 - Treatment of Early Stage/Localized Disease (ID 207)

    • Event: WCLC 2019
    • Type: E-Poster Viewing in the Exhibit Hall
    • Track: Treatment of Early Stage/Localized Disease
    • Presentations: 1
    • Now Available
    • Moderators:
    • Coordinates: 9/08/2019, 08:00 - 18:00, Exhibit Hall
    • +

      EP1.17-35 - CBCT Radiomics May Predict Short-Term SBRT Effect in Early Stage Lung Cancer Patients (Now Available) (ID 501)

      08:00 - 18:00  |  Author(s): Changhui Yu

      • Abstract
      • Slides

      Background

      This study aimed to determine whether radiomics features can be obtained from cone-beam CT (CBCT) through the linac based onboard-imaging systems.

      Method

      Thirty consecutive patients with early stage lung cancer treated with stereotactic body radiation therapy (SBRT) (Total dose:50-60Gy, Fraction:5-8) were included. CBCT scan were performed before delivery of each SBRT treatment. Diagnostic CT scan before Radiation Therapy (diagnostic CT) and follow-up CT at one month after radiotherapy (follow-up CT) were analyzed. Primary tumors were delineated manually and modified on diagnostic CT, CBCT and follow-up CT. Tumor size on diagnostic CT and follow-up CT were used to calculate the reduction rate. The primary endpoint was average daily tumor reduction rate. Radiomics features were extracted from first fraction CBCT (CBCT first), last fraction CBCT (CBCT last) and diagnostic CT by Imaging Biomarker Explorer (IBEX) software. Radiomic features were selected using correlation coefficient and LASSO dimensionality reduction based on R.

      Result

      A total of 222 radiomics features were obtained from CBCT first, CBCT last and diagnostic CT of each patient. Based on correlation coefficients>0.70 and with LASSO dimensionality reduction, 5, 4 and 5 features were selected in diagnostic CT, CBCT first and CBCT last, respectively. Comparing the features in three CT subsets, two features were same between diagnostic CT and CBCT first, three features were the same between diagnostic CT and CBCT last. Two features are common in all three CT imaging sets. (Table 1)

      Table 1 Different characteristic values of different CT radiomics be predicted SBRT reduction rate.

      Images

      diagnostic CT

      CBCT first

      CBCT last

      Feature

      Inverse Variance

      Inverse Variance

      Inverse Variance

      Percentile

      Percentile

      Percentile

      Complexity

      Cluster Shade

      Cluster Shade

      Correlation

      Max3D Diameter

      Correlation

      Inverse Diff Moment Norm

      Information MeasureCorr1

      Conclusion

      A few radiomics features may be robust to the noise in daily CBCT images which are often considered of poor quality. Study with larger sample size are needed to verify this interesting finding.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    JCSE01 - Joint IASLC-CSCO-CAALC Session (ID 63)

    • Event: WCLC 2019
    • Type: Joint IASLC-CSCO-CAALC Session
    • Track:
    • Presentations: 1
    • +

      JCSE01.17 - Modelling the Immunosuppressive Difference of SBRT and CRT by Simulating the Dose to Circulating Lymphocytes in Non-Small Cell Lung Cancer (ID 3431)

      07:00 - 11:15  |  Author(s): Changhui Yu

      • Abstract
      • Slides

      Abstract
      Background
      Radiation-dose delivered to circulating lymphocyte (CL) has detrimental effect on immune system for cancer patients. Our study established a model to compare the cumulative dose on CL of patients with conventional fractionation radiotherapy (CRT) and stereotactic body radiation therapy (SBRT) in lung cancer with different target volume.

      Methods
      The improved model is based on convolution algorithm suggested by Yovino(Cancer Investigation, 2013). The current blood DVHs of each organ were multiplied with treatment field DVH to generate original DVHs. During one second, 0.6% of whole-body blood circulates through each organ and rest body according to blood circulating pattern and then new DVHs of organ were generated. The new DVHs would be used for next second’s calculation with treatment field DVH. Conventional fractionated non-small cell lung cancer plan 60Gy (30 fractions*2.0Gy) and SBRT plan 50Gy (5fractions*10Gy) are constructed for three patients with different target volumes. The primary endpoint is peak cumulative blood dose (PCBC).

      Results
      PCBC of three patients with CRT and SBRT were calculated as Figure 1. PCBC with CRT to circulating lymphocyte (CL) were 2.5Gy, 5.6Gy, 9.5Gy in PTV-volume 17cm3, 33cm3, 120cm3, respectively. And PCBC with SBRT to circulating lymphocyte (CL) were 2.1Gy, 2.9Gy, 6.0Gy in PTV-volume 17cm3, 33cm3, 120cm3, respectively. PCBC gap of SBRT to circulating lymphocyte (CL) was decreased 0.4Gy, 2.7Gy, 3.5Gy in PTV-volume 17cm3, 33cm3, 120cm3, respectively.



      Conclusion
      An improved simulation-model was established, SBRT, compared to CRT, will lead to decreased cumulative dose on CL, which may cause less impact on immune system with the enlargement of PTV-volume.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    P1.04 - Immuno-oncology (ID 164)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Immuno-oncology
    • Presentations: 1
    • Now Available
    • Moderators:
    • Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
    • +

      P1.04-69 - Modelling the Immunosuppressive Difference of SBRT and CRT by Simulating the Dose to Circulating Lymphocytes in Non-Small Cell Lung Cancer (Now Available) (ID 295)

      09:45 - 18:00  |  Author(s): Changhui Yu

      • Abstract
      • Slides

      Background

      Radiation-dose delivered to circulating lymphocyte (CL) has detrimental effect on immune system for cancer patients. Our study established a model to compare the cumulative dose on CL of patients with conventional fractionation radiotherapy (CRT) and stereotactic body radiation therapy (SBRT) in lung cancer with different target volume.

      Method

      The improved model is based on convolution algorithm suggested by Yovino(Cancer Investigation, 2013). The current blood DVHs of each organ were multiplied with treatment field DVH to generate original DVHs. During one second, 0.6% of whole-body blood circulates through each organ and rest body according to blood circulating pattern and then new DVHs of organ were generated. The new DVHs would be used for next second’s calculation with treatment field DVH. Conventional fractionated non-small cell lung cancer plan 60Gy (30 fractions*2.0Gy) and SBRT plan 50Gy (5fractions*10Gy) are constructed for three patients with different target volumes. The primary endpoint is peak cumulative blood dose (PCBC).

      Result

      PCBC of three patients with CRT and SBRT were calculated as Figure 1. PCBC with CRT to circulating lymphocyte (CL) were 2.5Gy, 5.6Gy, 9.5Gy in PTV-volume 17cm3, 33cm3, 120cm3, respectively. And PCBC with SBRT to circulating lymphocyte (CL) were 2.1Gy, 2.9Gy, 6.0Gy in PTV-volume 17cm3, 33cm3, 120cm3, respectively. PCBC gap of SBRT to circulating lymphocyte (CL) was decreased 0.4Gy, 2.7Gy, 3.5Gy in PTV-volume 17cm3, 33cm3, 120cm3, respectively.

      figure 1.jpg

      Conclusion

      An improved simulation-model was established, SBRT, compared to CRT, will lead to decreased cumulative dose on CL, which may cause less impact on immune system with the enlargement of PTV-volume.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    P1.14 - Targeted Therapy (ID 182)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Targeted Therapy
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
    • +

      P1.14-40 - EGFR-TKIs May Sensitize Radiation Lung Damage in Stereotactic Body Radiotherapy Based on Intensity Analyzing (ID 297)

      09:45 - 18:00  |  Author(s): Changhui Yu

      • Abstract

      Background

      To measure early radiographic changes of acute radiation pneumonitis after stereotactic body radiotherapy (SBRT) and compare the differences between patients treated with and without the epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs).

      Method

      Patients with SBRT with 3-month follow-up CT scans were eligible. 20 patients treated with EGFR-TKIs a month before stereotactic body radiotherapy (Target-SBRT group) were formed the primary study population. Another 20 patients received SBRT alone were selected from our SBRT data bank to serve as control, by matching dose prescription, tumor size and location. Pre- and post-SBRT CT scans from these 40 patients were registered to each other and the mean value of CT intensity (Hounsfield unit, HU) were extracted for regions of the lungs receiving the same dose at 10 Gy intervals to generate dose-response curves (DRC). The frequency of density changes>200 HU was modeled depending on the fractionation using a Probit model for different treatments.

      Result

      There were significant differences in the DRC of pre-SBRT, post-SBRT and the differences of HU value (△HU) in lung between the SBRT alone and Target SBRT groups (all P<0.050)(Figure 1). The respective dose for a 50% complication risk (TD50) for changes>200HU was 72Gy (95% confidence interval (CI 58-107) in SBRT alone group versus 52Gy (CI 46-59) in targeted SBRT group (Figure 2).

      figure 1.jpg

      figure 2.jpg

      Conclusion

      Compared to SBRT alone, targeted SBRT group has a lower TD50 and m value, both suggesting an increased complication probability of normal lung tissue.