Radiation induced temporal lobe necrosis in nasopharyngeal cancer patients after radical external beam radiotherapy

Table 1 Summary of previous studies on the predictive parameters and dose tolerance of radiation induced temporal lobe necrosis (TLN)

Literature	Predictive Parameter	Proposed Dose Tolerance	Sample size (n)
Feng et al., 2018 [9]	D₂cc	TD_5/5 = 60.3 Gy TD_50/5 = 76.9 Gy	695
Sun et al., 2013 [34]	D_0.5cc	69.0 Gy	20
Su et al., 2012 [8]	D_max D₁cc rV₄₀ aV₄₀	< 68.0 Gy < 58.0 Gy < 10% 5 cm³	870
Zeng et al., 2015 [25]	D₁cc	TD_5/5 = 62.8 Gy TD_50/5 = 77.6 Gy	351
Huang et al., 2019 [35]	D_1cc D_max	≤ 71.14 Gy ≤ 72 Gy	506
Lee et al., 2019 [36]	D_0.03cc (T1–2 tumour) MAC (T3–4 tumour)	≤ 65 Gy ≤ 70 Gy	21^#
Zhou et al., 2014 [37]	aV₄₅	< 15.1 cm³	43
Kong et al., 2016 [38]	D_max D₁cc	TD_5/5 = 69.0 Gy TD_50/5 = 82.1 Gy TD_5/5 = 62.8 Gy TD_50/5 = 80.9 Gy	132

D₂cc = dose delivered to 2 cm³ volume of TL, Gy = Gray, TD_5/5 = tolerance dose for TLN incidence of ≧5% in 5 years, TD_50/5 = tolerance dose for TLN incidence of ≧50% in 5 years, D_0.5cc = dose delivered to 0.5 cm³ volume of TL, D_max = maximum point dose, D₁cc = dose delivered to 1 cm³ volume of TL, rV₄₀ = percent of TLs receiving ≧40 Gy, aV₄₀ = absolute volume of TLs receiving ≧40 Gy, D_0.03cc = dose delivered to 0.03 cm³ volume of TL, MAC = maximum acceptable criteria, aV₄₅ = absolute volume of TLs receiving ≧45 Gy. ^#number of oncology centres