Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

The head-scatter factor for small field sizes

T C Zhu1, B E Bjärngard

  • 1Department of Radiation Oncology, Roger Williams Cancer Center, Brown University, Providence, Rhode Island 02908.

Medical Physics
|January 1, 1994
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

SU-E-T-523: Modeling Beam Data for Flattening Filter Free (FFF) Photon Beams.

Medical physics·2017
Same author

Dosimetric consequences of pancreatic tumor motion when predetermined treatment margins are employed during intensity-modulated radiation therapy.

Journal of B.U.ON. : official journal of the Balkan Union of Oncology·2012
Same author

Preliminary results of interstitial motexafin lutetium-mediated PDT for prostate cancer.

Lasers in surgery and medicine·2006
Same author

Photodynamic therapy with motexafin lutetium for rectal cancer: a preclinical model in the dog.

The Journal of surgical research·2006
Same author

Doses near the surface during total-body irradiation with 15 MV X-rays.

International journal of cancer·2002
Same author

Characteristics of bremsstrahlung in electron beams.

Medical physics·2001
Same journal

Correction to "On the shape of the radiation survival curve in tumor spheroids: The role of oxygen heterogeneity".

Medical physics·2026
Same journal

Multi-view constrained semi-supervised vertebra detection for 3D ultrasound spine volume.

Medical physics·2026
Same journal

Accuracy of quantitative <sup>177</sup>Lu SPECT/CT imaging: A systematic review.

Medical physics·2026
Same journal

Physics-constrained dual-domain network for CBCT reconstruction from orthogonal X-rays in gynecologic radiotherapy.

Medical physics·2026
Same journal

Decomposition-based harmonization for quantitative PET imaging across scanners and radiotracers.

Medical physics·2026
Same journal

Development and evaluation of an in vivo dose-based monitoring system for electron FLASH radiation therapy.

Medical physics·2026
See all related articles

Head-scatter factors in linear accelerators are similar for larger fields but decrease significantly with smaller collimator openings. This phenomenon, influenced by photon scatter and collimator closure, can help estimate source size.

Area of Science:

  • Medical Physics
  • Radiation Oncology

Background:

  • Head-scatter factors (H) are crucial for accurate dose calculations in radiation therapy.
  • Understanding these factors is essential for optimizing treatment planning and delivery.

Purpose of the Study:

  • To investigate the behavior of head-scatter factors across different linear accelerators.
  • To identify the contributing components to head-scatter factors, particularly at small field sizes.

Main Methods:

  • Examination of head-scatter factors (H) for four distinct linear accelerators.
  • Analysis of H values in relation to varying field sizes and collimator openings.

Main Results:

  • Head-scatter factors were found to be consistent for field sizes exceeding 3 x 3 cm².

Related Experiment Videos

  • A notable reduction in head-scatter factors was observed with smaller collimator openings across all accelerators.
  • Photon scatter in beam path structures (e.g., flattening filter) contributes to a gradual increase in H with larger openings, potentially doubled by built-in wedges.

    • Conclusions:

    • The head-scatter factor comprises two main components: scatter from beam path structures and primary photon fluence reduction due to collimator closure.
    • Collimator closure significantly impacts fields smaller than 3 x 3 cm², reducing primary photon fluence.
    • The observed effect provides a method for estimating linear accelerator source size, correlating with bending magnet design.