Effect of ocular implants of different materials on the dosimetry of external beam radiation therapy. Academic Article uri icon

Overview

abstract

  • PURPOSE: To study the attenuation and scattering effects of ocular implants, made from different materials, on the dose distributions of a 6 MV photon beam, and 6, 9, and 12 MeV electron beams used in orbital radiotherapy. METHODS AND MATERIALS: Central axis depth-dose measurements were performed in a polystyrene phantom with embedded spherical ocular implants using film dosimetry of a 6 MV photon beam and electron beams of 6, 9, and 12 MeV energy. The isodose distributions were also calculated by a computerized treatment planning system using computerized tomography (CT) scans of a polystyrene phantom that had silicone, acrylic, and hydroxyapatite ocular implants placed into it. RESULTS: Electron beam dose distributions display distortions both on the measured and calculated data. This effect is most accentuated for the hydroxyapatite implants, for which the transmissions through ocular implants are on the order of 93% for the 6 MV photon beam, and range from 60% for 6 MeV electrons to 90% for 12 MeV electrons. CONCLUSION: We studied the effect of ocular implants of various materials, embedded in a polystyrene phantom, on the dose distributions of a 6 MV photon beam, and 6, 9, and 12 MeV electron beams. Our investigations show that while 6 MV photons experience only a few percent attenuation, lower energy electron beam with 60% transmission is not a suitable choice of treating tumors behind the ocular implants.

publication date

  • July 30, 1995

Research

keywords

  • Eye, Artificial
  • Models, Structural
  • Radiotherapy
  • Radiotherapy Dosage

Identity

Scopus Document Identifier

  • 0029154948

Digital Object Identifier (DOI)

  • 10.1016/0360-3016(94)00611-N

PubMed ID

  • 7635792

Additional Document Info

volume

  • 32

issue

  • 5