Skip to main content

Table 2 Comparison between the actual treated plan (prescribed almost exclusively at the 50% IDL), a re-plan using the shot within shot technique prescribed at the 50% IDL (SS50%), and a re-plan using the shot within shot technique prescribed at the optimal IDL (SSopt)

From: Optimization of the prescription isodose line for Gamma Knife radiosurgery using the shot within shot technique

Case Vol (cc) RX (Gy) IDL (%) Selectivity Gradient index Brain V12Gy (cc) ΔT1 (%) ΔT2 (%)
    SSopt Plan SS50% SSopt Plan SS50% SSopt Plan SS50% SSopt Plan - SS50% Plan - SSopt SS50% - SSopt
1A 0.21 21 65 0.67 0.51 0.50 3.50 2.62 2.63 0.68 0.69 0.71 35 53 28
2A 0.09 21 52 0.51 0.61 0.61 3.53 3.39 3.50 0.40 0.31 0.33 0 4 4
2A 0.10 21 51 0.31 0.58 0.58 2.78 3.42 3.45 0.64 0.37 0.38 0 0 0
2B 0.16 21 74 0.47 0.47 0.48 2.87 3.03 3.07 0.59 0.58 0.59 1 39 38
2C 1.13 18 65 0.72 0.72 0.67 3.20 3.10 2.96 2.00 1.99 2.16 48 61 25
3A 1.58 21 67 0.67 0.73 0.72 3.06 2.60 2.56 4.26 3.03 3.00 14 37 27
3B 0.16 21 58 0.67 0.74 0.73 3.17 3.22 3.31 0.45 0.41 0.44 1 15 16
3C 0.05 21 50 0.45 0.45 0.45 2.85 2.84 2.84 0.19 0.19 0.19 0 0 0
4A 0.18 21 76 0.64 0.58 0.67 3.63 2.84 3.08 0.62 0.52 0.50 29 56 38
4B 0.18 21 74 0.64 0.55 0.59 3.46 2.80 2.89 0.60 0.55 0.56 24 51 36
4C 0.11 21 63 0.71 0.50 0.52 3.58 3.17 3.39 0.34 0.46 0.49 16 35 23
4D 2.22 18 60 0.81 0.79 0.77 2.50 2.61 2.62 2.56 2.76 2.78 17 29 14
5A 1.40 20 75 0.74 0.60 0.61 3.17 2.55 2.52 3.20 3.18 3.03 62 76 37
5B 0.61 20 52 0.63 0.56 0.56 3.52 3.42 3.48 1.86 2.20 2.28 15 18 4
5C 0.04 20 57 0.37 0.22 0.22 3.17 3.26 3.40 0.25 0.46 0.44 19 30 14
6A 0.48 21 50 0.63 0.60 0.60 3.24 3.37 3.37 1.51 1.72 1.72 0 0 0
6B 0.83 21 56 0.68 0.54 0.56 2.99 2.95 3.08 2.20 2.94 2.92 46 52 11
6C 0.16 21 74 0.67 0.67 0.65 3.11 3.11 3.22 0.45 0.45 0.49 0 36 36
6D 0.11 21 77 0.40 0.40 0.38 2.91 2.91 2.89 0.58 0.58 0.61 0 40 40
7A 0.83 20 71 0.54 0.37 0.40 3.89 2.57 2.58 3.60 3.58 3.34 19 45 32
  1. Reduction in beam-on times are shown in a comparison between the re-plans and the treated plan (ΔT1), and in comparison between the SS50% plan and optimized plan (ΔT2)