Radiation-induced temporal lobe injury for nasopharyngeal carcinoma: a comparison of intensity-modulated radiotherapy and conventional two-dimensional radiotherapy

PLoS One. 2013 Jul 10;8(7):e67488. doi: 10.1371/journal.pone.0067488. Print 2013.

Abstract

Background: To compare the radiation-induced temporal lobe injury (TLI) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT) or two-dimensional conventional radiotherapy (2D-CRT).

Patients and methods: 1276 cases of NPC treated with IMRT or 2D-CRT were retrospectively reviewed. A diagnosis of TLI was made on follow-up magnetic resonance imaging (MRI).

Results: The crude incidence of TLI was 7.5% and 10.8% (P = 0.048), and the actuarial 5-year incidence was 16% and 34.9% (P<0.001) for the IMRT and 2D-CRT groups, respectively. Multivariate analysis revealed both T stage (P<0.001) and radiation technique (P<0.001) as independent predictors. Patients with T1, T2 and T3 disease had a significantly higher risk when treated with 2D-CRT (P = 0.005, 0.016, <0.001, respectively). This trend was not evident for T4 patients (P = 0.680). The 2D-CRT group had a longer latency for the development of TLI (P<0.001). Those with T4 disease had a shorter median time to TLI (P = 0.006, 0.042, <0.001 when compared with T1, T2 and T3, respectively).

Conclusions: IMRT is superior to 2DRT for the management of T1-T3 NPC in terms of sparing the temporal lobe. The high incidence of TLI in T4 disease needs to be addressed.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Carcinoma
  • Child
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Nasopharyngeal Carcinoma
  • Nasopharyngeal Neoplasms / epidemiology
  • Nasopharyngeal Neoplasms / radiotherapy*
  • Radiation Injuries / epidemiology
  • Radiation Injuries / etiology*
  • Radiotherapy, Conformal / adverse effects*
  • Radiotherapy, Intensity-Modulated / adverse effects*
  • Retrospective Studies
  • Temporal Lobe / injuries*
  • Temporal Lobe / radiation effects
  • Young Adult

Grants and funding

This work was supported by grants from the Project Supported by Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2010), the Science Foundation of Key Hospital Clinical Program of Ministry of Health, P. R. China (No.2010-178); and the National Natural Science Foundation of China (No. 81071836). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.