Comparison of daily megavoltage electronic portal imaging or kilovoltage imaging with marker seeds to ultrasound imaging or skin marks for prostate localization and treatment positioning in patients with prostate cancer

Christopher F. Serago, Steven J. Buskirk, Todd C. Igel, Ashley A. Gale, Nicole E. Serago, John D. Earle

Research output: Contribution to journalArticle

63 Scopus citations

Abstract

Purpose: To compare the accuracy of imaging modalities, immobilization, localization, and positioning techniques in patients with prostate cancer. Methods and Materials: Thirty-five patients with prostate cancer had gold marker seeds implanted transrectally and were treated with fractionated radiotherapy. Twenty of the 35 patients had limited immobilization; the remaining had a vacuum-based immobilization. Patient positioning consisted of alignment with lasers to skin marks, ultrasound or kilovoltage X-ray imaging, optical guidance using infrared reflectors, and megavoltage electronic portal imaging (EPI). The variance of each positioning technique was compared to the patient position determined from the pretreatment EPI. Results: With limited immobilization, the average difference between the skin marks' laser position and EPI pretreatment position is 9.1 ± 5.3 mm, the average difference between the skin marks' infrared position and EPI pretreatment position is 11.8 ± 7.2 mm, the average difference between the ultrasound position and EPI pretreatment position is 7.0 ± 4.6 mm, the average difference between kV imaging and EPI pretreatment position is 3.5 ± 3.1 mm, and the average intrafraction movement during treatment is 3.4 ± 2.7 mm. For the patients with the vacuum-style immobilization, the average difference between the skin marks' laser position and EPI pretreatment position is 10.7 ± 4.6 mm, the average difference between kV imaging and EPI pretreatment position is 1.9 ± 1.5 mm, and the average intrafraction movement during treatment is 2.1 ± 1.5 mm. Conclusions: Compared with use of skin marks, ultrasound imaging for positioning provides an increased degree of agreement to EPI-based positioning, though not as favorable as kV imaging fiducial seeds. Intrafraction movement during treatment decreases with improved immobilization.

Original languageEnglish (US)
Pages (from-to)1585-1592
Number of pages8
JournalInternational Journal of Radiation Oncology Biology Physics
Volume65
Issue number5
DOIs
StatePublished - Aug 1 2006

Keywords

  • Fiducial markers
  • Imaging
  • Localization
  • Prostate cancer
  • Radiotherapy

ASJC Scopus subject areas

  • Radiation
  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research

Fingerprint Dive into the research topics of 'Comparison of daily megavoltage electronic portal imaging or kilovoltage imaging with marker seeds to ultrasound imaging or skin marks for prostate localization and treatment positioning in patients with prostate cancer'. Together they form a unique fingerprint.

  • Cite this