Impact of Intensity Modulated Radiation Therapy as a Boost Treatment on the Lung Dose Distributions for Non- Small-Cell Lung Cancer

Journal of Lung Cancer 2005년 4권 1호 p.6 ~ p.14

최영민(Choi Young-Min) - 동아대학교 의과대학 방사선종양학교실
이형식(Lee Hyung-Sik) - 동아대학교 의과대학 방사선종양학교실
허원주(Hur Won-Joo) - 동아대학교 의과대학 방사선종양학교실
김효진(Kim Hyo-Jin) - 동아대학교 의과대학 내과학교실
김재석(Kim Jae-Seok) - 동아대학교 의과대학 내과학교실
권혁찬(Kwon Hyuk-Chan) - 동아대학교 의과대학 내과학교실
김성현(Kim Sung-Hyun) - 동아대학교 의과대학 내과학교실
손춘희(Son Choon-Hee) - 동아대학교 의과대학 내과학교실
양두경(Yang Doo-Kyung) - 동아대학교 의과대학 내과학교실
이수걸(Lee Soo-Keol) - 동아대학교 의과대학 내과학교실

Abstract

Purpose: To investigate the feasibility of intensity modulated radiotherapy (IMRT) as a method of boost radiotherapy following the initial irradiation by the conventional anterior / posterior opposed beams for centrally located non-small-cell lung cancer through the evaluation of dose distributions according to the various boost methods.

Materials and Methods: Seven patients with T3 or T4 lung cancer and mediastinal node enlargement who previously received radiotherapy were studied. All patients underwent virtual simulation retrospectively with the previous treatment planning CTs. Initial radiotherapy plans were designed to deliver 40 Gy to the primary tumor and involved nodal regions with the conventional anterior / posterior opposed beams. Two radiation dose levels, 24 and 30 Gy, were used for the boost radiotherapy plans, and 4 different boost methods (a three dimensional conformal radiotherapy (3DCRT), 5, 7, and 9-beams IMRT) were applied to each dose level. The goals of the boost plans were to deliver the prescribed radiation dose to 95% of the planning target volume (PTV) and minimize the volumes of the normal lungs and spinal cord irradiated above their tolerance doses. Dose distributions in the PTVs and lungs, according to the four types of boost plans, were compared in the boost and sum plans, respectively.

Results: The percentage of lung volumes irradiated >20 Gy (V20) were reduced significantly in the IMRT boost plans compared with the 3DCRT boost plans at the 24 and 30 Gy dose levels (p=0.007 and 0.031 respectively). Mean lung doses according to the boost methods were not different in the 24 and 30 Gy boost plans. The conformity indexes (CI) of the IMRT boost plans were lower than those of the 3DCRT plans in the 24 and 30 Gy plans (p=0.001 in both). For the sum plans, there was no difference of the dose distributions in the PTVs and lungs according to the boost methods.

Conclusion: In the boost plans the V20s and CIs were reduced significantly by the IMRT plans, but in the sum plans the effects of IMRT to the dose distributions in the tumor and lungs, like CI and V20, were offset. Therefore, in order to keep the beneficial effect of IMRT in radiotherapy for lung cancer, it would be better to use IMRT as a whole treatment plan rather than as a boost treatment.

키워드

Non-small-cell lung cancer, Intensity modulated radiotherapy, Three dimensional conformal radiotherapy, Boost radiotherapy, Lung dose volume
원문 및 링크아웃 정보
등재저널 정보
주제코드
주제명(Target field)
연구대상(Population)
연구참여(Sample size)
대상성별(Gender)
질병특성(Condition Category)
연구환경(Setting)
연구설계(Study Design)
연구기간(Period)
중재방법(Intervention Type)
중재명칭(Intervention Name)
키워드(Keyword)
유효성결과(Recomendation)
The percentage of lung volumes irradiated >20 Gy (V20) were reduced significantly in the IMRT boost plans compared with the 3DCRT boost plans at the 24 and 30 Gy dose levels (p=0.007 and 0.031 respectively).
연구비지원(Fund Source)
근거수준평가(Evidence Hierarchy)
출판년도(Year)
참여저자수(Authors)
대표저자
DOI
KCD코드
ICD 03
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