PMC3166780_01
Axial section through the brainstem at the nerve root entry zone of the left trigeminal nerve with an illustration of the location of the 50% isodose line for gamma knife radiation treatment planning. This was the treatment location for the first and second gamma knife procedures.
CRIM2011-258910.001.jpg
PMC3166780_01_CRIM2011-258910.001.jpg
fig1
The patient elected to undergo GKRS which was performed with a Leksell model C gamma knife to the trigeminal nerve root entry zone with 201 cobalt sources (4 mm shot size) to a dose of 42 Gy prescribed to the 50% isodose line for a maximum point dose of 84 Gy (see Figure 1).
Axial section through the brainstem at the nerve root entry zone of the left trigeminal nerve with an illustration of the location of the 50% isodose line for the gamma knife radiation treatment planning. This was the location of treatment for his third course of treatment.
CRIM2011-258910.002.jpg
PMC3166780_01_CRIM2011-258910.002.jpg
fig2
The 3rd treatment was delivered a few millimeters distal from the previous target and was prescribed 20 Gy (with 4 mm shots) to the 50% isodose line (see Figure 2) for a maximum point dose of 40 Gy.