Parotid perfusion in nasopharyngeal carcinoma patients in early-to-intermediate stage after low-dose intensity-modulated radiotherapy: Evaluated by fat-saturated dynamic contrast-enhanced magnetic resonance imaging

Cheng Chieh Cheng, Su Chin Chiu, Yee Min Jen, Hing Chiu Chang, Hsiao Wen Chung, Yi Jui Liu, Hui Chu Chiu, Cheng Yu Chen, Guo Shu Huang, Chun Jung Juan

Research output: Contribution to journalArticle

8 Citations (Scopus)


Purpose: To investigate parotid perfusion in early-to-intermediate stage after parotid-sparing radiation dose using fat-saturated DCE-MRI, and to verify whether the perfusion alteration was related to radiation dose and the PSV. Methods and Materials: Thirty-two parotid glands from 16 consecutive patients with pathologically proven nasopharyngeal carcinoma treated by IMRT were examined. The parotid glands received a radiation dose of 28.9. ±. 3.9. Gy with a PSV of 43.1%. ±. 13.9%. Perfusion parameters were calculated using time-shifted Brix model from fat-saturated DCE-MRI data before (pre-RT) and in early-to-intermediate stage after (post-RT) IMRT. Paired t-test was used to evaluate perfusion changes, while Pearson's correlation test was used to examine perfusion dependency on radiation dose and PSV. For multiple comparisons Bonferroni correction was applied. Results: Successful fat saturation was achieved in 29 of 32 parotid glands. Compared with pre-RT, the post-RT parotid glands showed significantly higher A, peak enhancement, and wash-in slope, plus a lower Kel, suggesting a mixed effect of increased vascular permeability and acinar loss. Linear regression showed that peak enhancement was positively associated with radiation dose in post-RT parotid glands. Kel and slope were negatively associated with PSV, while time-to-peak was positively associated with PSV significantly. Conclusions: Our results suggest that time-shifted Brix model is feasible for quantifying parotid perfusion using DCE-MRI. The perfusion alterations in early-to-intermediate stage after IMRT might be related to a mixed effect of increased vascular permeability and acinar loss with dose and PSV dependencies.

Original languageEnglish
Pages (from-to)1278-1284
Number of pages7
JournalMagnetic Resonance Imaging
Issue number8
Publication statusPublished - Oct 2013
Externally publishedYes


ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging
  • Biomedical Engineering

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