An interactive treatment planning system for ophthalmic plaque radiotherapy

Journal Article · Thu Mar 01 00:00:00 EST 1990 · International Journal of Radiation Oncology, Biology and Physics; (USA)

DOI:https://doi.org/10.1016/0360-3016(90)90077-W· OSTI ID:7192354

Astrahan, M A; Luxton, G; Jozsef, G; Kampp, T D; Liggett, P E; Sapozink, M D; Petrovich, Z ^[1]

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1. Univ. of Southern California School of Medicine, Los Angeles (USA)

Brachytherapy using removable episcleral plaques containing sealed radioisotope sources is being studied as an alternative to enucleation in the treatment of choroidal melanoma and other tumors of the eye. Encouraging early results have been reported, but late complications which lead to loss of vision continue to be a problem. A randomized national study, the Collaborative Ocular Melanoma Study (COMS) is currently in progress to evaluate the procedure. The COMS specified isotope is 125I. Precise dosimetric calculations near the plaque may correlate strongly with complications and could also be used to optimize isotope loading patterns in the plaques. A microcomputer based treatment planning system has been developed for ophthalmic plaque brachytherapy. The program incorporates an interactive, 3-dimensional, solid-surface, color-graphic interface. The program currently supports 125I and 192Ir seeds which are treated as anisotropic line sources. Collimation effects related to plaque structure are accounted for, permitting detailed study of shielding effectiveness near the lip of a plaque. A dose distribution matrix may be calculated in any subregion of a transverse, sagittal, or coronal planar cross section of the eye, in any plane transecting the plaque and crossing the eye diametrically, or on a spherical surface within or surrounding the eye. Spherical surfaces may be displayed as 3-dimensional perspective projections or as funduscopic diagrams. Isodose contours are interpolated from the dose matrix. A pointer is also available to explicitly calculate and display dose at any location on the dosimetry surface. An interactive editing capability allows new plaque designs to be rapidly added to the system.

• OSTI ID: 7192354
• Journal Information: International Journal of Radiation Oncology, Biology and Physics; (USA), Vol. 18:3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
EYES
NEOPLASMS
RADIOTHERAPY
PLANNING
COMPUTER GRAPHICS
IODINE 125
IRIDIUM 192
MAN
MICROCOMPUTERS
OPHTHALMOLOGY
RADIATION DOSE DISTRIBUTIONS
SEALED SOURCES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
BODY AREAS
COMPUTERS
DAYS LIVING RADIOISOTOPES
DIGITAL COMPUTERS
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
FACE
HEAD
HEAVY NUCLEI
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE ISOTOPES
IRIDIUM ISOTOPES
ISOMERIC TRANSITION
ISOTOPES
MAMMALS
MEDICINE
NUCLEAR MEDICINE
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PRIMATES
RADIATION SOURCES
RADIOISOTOPES
RADIOLOGY
SENSE ORGANS
THERAPY
VERTEBRATES
550603* - Medicine- External Radiation in Therapy- (1980-)