Study on the Dose Uncertainties in the Lung during Passive Proton Irradiation with a Proton Beam Range Compensator

Seung Hoon Yoo, Jae Man Son, Myonggeun Yoon, Sung Yong Park, Dongho Shin, Byung Jun Min

Research output: Contribution to journalArticle


A moving phantom is manufactured for mimicking lung model to study the dose uncertainty from CT number-stopping power conversion and dose calculation in the soft tissue, light lung tissue and bone regions during passive proton irradiation with compensator smearing value. The phantom is scanned with a CT system, and a proton beam irradiation plan is carried out with the use of a treatment planning system (Eclipse). In the case of the moving phantom, a RPM system is used for respiratory gating. The uncertainties in the dose distribution between the measured data and the planned data are investigated by a gamma analysis with 3%-3 mm acceptance criteria. To investigate smearing effect, three smearing values (0.3 cm, 0.7 cm, 1.2 cm) are used to for fixed and moving phantom system. For both fixed and moving phantom, uncertainties in the light lung tissue are severe than those in soft tissue region in which the dose uncertainties are within clinically tolerable ranges. As the smearing value increases, the uncertainty in the proton dose distribution decreases.

Original languageEnglish
Pages (from-to)1369-1378
Number of pages10
JournalJournal of the Korean Physical Society
Issue number11
Publication statusPublished - 2018 Jun 1



  • Dose uncertainty
  • Gating
  • Lung phantom
  • Proton therapy

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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