Radiation-induced temporal lobe injury after intensity modulated radiotherapy in nasopharyngeal carcinoma patients: a dose-volume-outcome analysis

摘要

Background To identify the radiation volume effect and significant dosimetric parameters for temporal lobe injury (TLI) and determine the radiation dose tolerance of the temporal lobe (TL) in nasopharyngeal carcinoma (NPC) patients treated with intensity modulated radiation therapy (IMRT). Methods Twenty NPC patients with magnetic resonance imaging (MRI)-diagnosed unilateral TLI were reviewed. Dose-volume data was retrospectively analyzed. Results Paired samples t -tests showed all dosimetric parameters significantly correlated with TLI, except the TL volume (TLV) and V₇₅ (the TLV that received ≥75?Gy, P =?0.73 and 0.22, respectively). Receiver operating characteristic (ROC) curves showed V₁₀ and V₂₀ ( P =?0.552 and 0.11, respectively) were the only non-significant predictors from V₁₀ to V₇₀ for TLI. D_0.5cc (dose to 0.5?ml of the TLV) was an independent predictor for TLI ( P 0.5cc was 0.843 ( P Conclusions A D_0.5cc of 69?Gy may be the dose tolerance of the TL. The risk of TLI was highly dependent on high dose ‘hot spots’ in the TL; physicians should be cautious of such ‘hot spots’ in the TL during IMRT treatment plan optimization, review and approval.