Imaging doses and secondary cancer risk from kilovoltage cone-beam ct in radiation therapy

Dong Wook Kim, Weon Kuu Chung, Myonggeun Yoon

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)


The authors assessed the radiation-induced cancer risk due to organ doses from kilovoltage (kV) cone beam computed tomography (CBCT), a verification technique in image-guided radiotherapy (IGRT). CBCTs were performed for three different treatment sites: the head and neck, chest, and pelvis. Using a glass dosimeter, primary doses versus depth were measured inside a homemade phantom, and organ doses were measured at various locations inside an anthropomorphic phantom. The excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) for cancer induction were estimated using the BEIR VII models based on dose measurement. The average primary (i.e., in-field) doses at the center of the phantom for standard imaging options were 1.9, 5.1, and 16.7 cGy for the head and neck, chest, and pelvis, respectively. The average secondary dose per scan for the pelvis measured 20-50 cm from the isocenter and ranged from 0.67-0.02 cGy, whereas the secondary dose per scan for the head and neck ranged from 0.07-0.003 cGy, indicating that CBCT for treatment of the head and neck is associated with a smaller secondary radiation dose than CBCT for treatment of the pelvis. The estimation of LAR from CBCT in IGRT indicated that the lifetime cancer risk for major organs can reach approximately 400 per 10,000 persons if 30 CBCT scans are performed to position a patient during radiation treatment of the pelvis site.

Original languageEnglish
Pages (from-to)499-503
Number of pages5
JournalHealth Physics
Issue number5
Publication statusPublished - 2013 May


  • computed tomography
  • radiation protection
  • radiotherapy
  • risk estimates

ASJC Scopus subject areas

  • Epidemiology
  • Radiology Nuclear Medicine and imaging
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'Imaging doses and secondary cancer risk from kilovoltage cone-beam ct in radiation therapy'. Together they form a unique fingerprint.

Cite this