Seed strength determination for eye plaque therapy.
Standardized radioactive plaques have been used in the irradiation of intraocular tumors. These plaques have defined slots to accommodate 125I seeds and hence produce predictable isodose distributions. The seed strength has to be adjusted to deliver 100 Gy to the prescription point, which varies with the tumor size. The purpose of this work is to develop lookup tables that relate the seed strength to different prescription distances. Dose rates were determined for a set of standardized eye plaques. Using these dose rates and the source strength decaying expression, the seed strengths were determined as a function of distance along a line through the plaque. Two seed-strength tables were created based on four-day and five-day treatment times delivering a 100 Gy to the prescription distance.
Department of Radiation Oncology, University of Pittsburgh School of Medicine, PA 15213.
C B
CB
Saw
M
M
Seidel
T
T
Pawlicki
A
A
Wu
K
K
Karasek
D001918:Brachytherapy / Q000295:instrumentation; D005134:Eye Neoplasms / Q000532:radiotherapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D011879:Radiotherapy Dosage
D007457:Iodine Radioisotopes