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  • [Radiat Oncol.] Normal lung sparing Tomotherapy technique in stage III lung cancer.

    성균관의대 / 홍채선, 주상규*, 안용찬*

  • 출처
    Radiat Oncol.
  • 등재일
    2017 Nov 6
  • 저널이슈번호
    12(1):167. doi: 10.1186/s13014-017-0905-x.
  • 내용

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    Abstract

    PURPOSE:
    Radiation pneumonitis (RP) has been a challenging obstacle in treating stage III lung cancer patients. Beam angle optimization (BAO) technique for Tomotherapy was developed to reduce the normal lung dose for stage III non-small cell lung cancer (NSCLC). Comparative analyses on plan quality by 3 different Intensity-modulated radiation therapy (IMRT) methods with BAO were done.

    MATERIALS AND METHODS:
    Ten consecutive stage IIIB NSCLC patients receiving linac-based static IMRT (L-IMRT) with total 66 Gy in 33 fractions to the PTV were selected. Two additional Tomotherapy-based IMRT plans (helical beam (TH-IMRT) and static beam (TD-IMRT)) were generated on each patient. To reduce the normal lung dose, Beam angles were optimized by using complete and directional block functions in Tomotherapy based on knowledge based statistical analysis. Plan quality was compared with target coverage, normal organ sparing capability, and normal tissue complication probability (NTCP). Actual beam delivery times and risk of RP related with planning target volume (PTV) were also evaluated.

    RESULTS:
    The best PTV coverage measured by conformity index and homogeneity index was achievable by TH-IMRT (0.82 and 1.06), followed by TD-IMRT (0.81 and 1.07) and L-IMRT (0.75 and 1.08). Mean lung dose was the lowest in TH-IMRT plan followed by TD-IMRT and L-IMRT, all of which were ≤20 Gy. TH-IMRT plan could significantly lower the lung volumes receiving low to medium dose levels: V5~30 when compared to L-IMRT plan; and V5~20 when compared to TD-IMRT plan, respectively. TD-IMRT plan was significantly better than L-IMRT with respects to V20 and V30 and there was no significant difference with respect to V40 among three plans. The NTCP of the lung was the lowest in TH-IMRT plan, followed by TD-IMRT and L-IMRT (6.42% vs. 6.53% vs. 8.11%). Beam delivery time was the shortest in TD-IMRT plan followed by L-IMRT. As PTV length increased, NTCP and Mean lung dose proportionally increased significantly in all three plans.

    CONCLUSION:
    Advantageous profiles by TH-IMRT could be achieved by BAO by complete and directional block functions. Current observation could help radiation oncologists to make wise selection of IMRT method for stage IIIB NSCLC

     

     

    Author information

    Hong CS1, Ju SG2, Ahn YC3,4, Yoo GS1, Noh JM1, Oh D1, Chung K1, Pyo H1, Jo K1.
    1
    Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea.
    2
    Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea. sg.ju@samsung.com.
    3
    Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea. ycahn.ahn@samsung.com.
    4
    Department of Medical Device Management and Research, SAIHST, Sungkyunkwan University, Irwon-Ro 81, Gangnam-Gu, Seoul, 06351, South Korea. ycahn.ahn@samsung.com.

  • 키워드
    Intensity-modulated radiotherapy; Lung cancer; Radiation pneumonitis; Tomotherapy
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