Leksell gamma unit model c

Radiosurgery was performed using the Leksell Gamma Unit Model C (Elekta Instrument, Inc). The median lesion volume was 3.1 ml (0.03–28.9 ml). Figure 2 presents a typical dose plan for a representative case. The prescription dose was set at an isodose level of 50–90%, and the median margin dose was 11.9 Gy (range 8.5–18 Gy). A higher margin dose (>12 Gy) was avoided due to the benign nature of the lesions and used only in the early part of this study. A higher margin dose (>12 Gy) was avoided due to the benign nature of the lesions and used only in the early part of this stud To achieve a highly conformal dose distribution, multiple small shots were used to maximize the mean dose and minimize the radiation volume outside the target. No identifiable portion of the facial nerve received more than 13 Gy and the trigeminal nerve received no more than 15 Gy. The margin dose administered to tumors that bulged into tissue of the brainstem was reduced to 11 Gy. y. To achieve a highly conformal dose distribution, multiple small shots were used to maximize the mean dose and minimize the radiation volume outside the target. No identifiable portion of the facial nerve received more than 13 Gy and the trigeminal nerve received no more than 15 Gy. The margin dose administered to tumors that bulged into tissue of the brainstem was reduced to 11 Gy.