Dose distribution around a 3.0-mm type 6702 I-125 seed

E. C. Scarbrough, G. E. Sanborn, J. A. Anderson, P. D. Nguyen, J. Y. Niederkorn, P. P. Antich

Research output: Contribution to journalArticle

5 Scopus citations


The 3M Company recently produced a special version of the type 6702 seed for use in animal studies of ocular melanoma. The seed consists of a single I-125 impregnated ion exchange resin sphere encapsulated in a 3.0-mm-long titanium cylinder, as opposed to the normal 4.5-mm cylinder containing from three to five resin spheres. Monte Carlo simulations and measurements show that the dose distribution around the 3-mm capsule differs in places by up to 10% from that of the 4.5-mm seed. In addition, the two seed types differ by 12% in the ratio of dose in tissue along the transverse seed axis to apparent activity. These differences must be taken into account when using these seeds.

Original languageEnglish (US)
Pages (from-to)460-463
Number of pages4
JournalMedical Physics
Issue number3
Publication statusPublished - 1990



  • brachytherapy
  • I-125 dosimetry
  • Monte Carlo
  • ocular melanoma

ASJC Scopus subject areas

  • Biophysics

Cite this

Scarbrough, E. C., Sanborn, G. E., Anderson, J. A., Nguyen, P. D., Niederkorn, J. Y., & Antich, P. P. (1990). Dose distribution around a 3.0-mm type 6702 I-125 seed. Medical Physics, 17(3), 460-463.