Development of a stereotactic device for gamma knife irradiation of small animals.
OBJECTIVE
The authors developed a stereotactic device for irradiation of small animals with Leksell Gamma Knife(R) Model C. Development and verification procedures were described in this article.


METHODS
The device was designed to satisfy three requirements. The mechanical accuracy in positioning was to be managed within 0.5 mm. The strength of the device and structure were to be compromised to provide enough strength to hold a small animal during irradiation and to interfere the gamma ray beam as little as possible. The device was to be used in combination with the Leksell G-frame(R) and KOPF(R) rat adaptor. The irradiation point was determined by separate imaging sequences such as plain X-ray images.


RESULTS
The absolute dose rate with the device in a Leksell Gamma Knife was 3.7% less than the value calculated from Leksell Gamma Plan(R). The dose distributions measured with GAFCHROMIC(R) MD-55 film corresponded to those of Leksell Gamma Plan(R) within acceptable range. The device was used in a series of rat experiments with a 4 mm helmet of Leksell Gamma Knife.


CONCLUSIONS
A stereotactic device for irradiation of small animals with Leksell Gamma Knife Model C has been developed so that it fulfilled above requirements. Absorbed dose and dose distribution at the center of a Gamma Knife helmet are in acceptable ranges. The device provides enough accuracy for stereotactic irradiation with acceptable practicality.
Chung
Hyun-Tai
HT
Department of Neurosurgery , Seoul National University, College of Medicine, Seoul, Korea.
Chung
Young Seob
YS
Kim
Dong Gyu
DG
Paek
Sun Ha
SH
Cho
Keun-Tae
KT