Backscatter measurements from a single seed of /sup 125/I for ophthalmic plaque dosimetry

Journal Article · Sun May 01 04:00:00 EDT 1988 · Med. Phys.; (United States)

OSTI ID:7109162

Luxton, G; Astrahan, M A; Petrovich, Z

To determine the dosimetric effect of a gold plaque applicator used in /sup 125/I ophthalmic irradiation, relative dose rates at points 2--18 mm transverse to the axis of a single seed of /sup 125/I were measured in an acrylic phantom under three different measurement conditions. The detectors were 1-mm diameter x 3-mm length LiF thermoluminescent dosimeters (TLD's). Conditions corresponded to the following: (i) full scatter, (ii) the presence of an ophthalmic gold plaque, and (iii) no scatter material on the side of the seed opposite to the TLD's. The dose rate with the gold plaque is less than that with full scatter phantom. There is no significant decrease in dose rate at 2.2 mm from the seed. Dose rate is significantly reduced at greater distances. The does rate decrease ranges from 4% at 5 mm to 10% at 18 mm. The /sup 125/I seed in the gold plaque gives 3%--5% higher dose rate than in the absence of backscatter material.

• Research Organization: Department of Radiation Oncology, University of Southern California, Los Angeles, California 90033
• OSTI ID: 7109162
• Journal Information: Med. Phys.; (United States), Journal Name: Med. Phys.; (United States) Vol. 15:3; ISSN MPHYA
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
655003* -- Medical Physics-- Dosimetry
BACKSCATTERING
BETA DECAY RADIOISOTOPES
BODY
BODY AREAS
DAYS LIVING RADIOISOTOPES
DOSE RATES
DOSIMETRY
ELECTRON CAPTURE RADIOISOTOPES
EYES
FACE
GAMMA DOSIMETRY
HEAD
IMPLANTS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
IRRADIATION
ISOTOPES
MEDICINE
MOCKUP
NUCLEAR MEDICINE
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PHANTOMS
RADIATION SOURCE IMPLANTS
RADIATION SOURCES
RADIOISOTOPES
RADIOLOGY
RADIOTHERAPY
SCATTERING
SENSE ORGANS
STRUCTURAL MODELS
THERAPY