Dose distribution around a 3.0-mm type 6702 I-125 seed.
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.
Scarbrough
E C
EC
Department of Radiology, University of Texas Southwestern Medical Center, Dallas 75235-9071.
Sanborn
G E
GE
Anderson
J A
JA
Nguyen
P D
PD
Niederkorn
J Y
JY
Antich
P P
PP
D000818:Animals; D001918:Brachytherapy / Q000295:instrumentation*; D005134:Eye Neoplasms / Q000532:radiotherapy; D007457:Iodine Radioisotopes; D008545:Melanoma / Q000532:radiotherapy; D008961:Models, Structural; D011879:Radiotherapy Dosage
D007457:Iodine Radioisotopes