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
Journal
Magnetic Resonance Imaging
Journal Volume
31
Journal Issue
8
Pages
1278-1284
Date Issued
2013
Author(s)
Cheng, C.-C.
Chiu, S.-C.
Jen, Y.-M.
Chang, H.-C.
Chung, H.-W.
Liu, Y.-J.
Chiu, H.-C.
Chen, C.-Y.
Huang, G.-S.
Juan, C.-J.
Abstract
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. ? 2013 Elsevier Inc.
SDGs
Other Subjects
acinar cell; adolescent; adult; aged; article; blood vessel permeability; cancer patient; cancer staging; cell loss; clinical article; clinical protocol; contrast enhancement; controlled study; disease association; dosimetry; feasibility study; female; human; image analysis; intensity modulated radiation therapy; male; nasopharynx carcinoma; nuclear magnetic resonance imaging; organ perfusion; outcome assessment; parotid gland; parotid perfusion; patient assessment; priority journal; radiation dose distribution; treatment response; a.u.; arbitrary unit; CNR; contrast-to-noise ratio; DCE; dynamic contrast-enhanced; EES; extracellular extravascular space; IMRT; intensity modulated radiotherapy; nasopharyngeal carcinoma; NPC; parotid sparing volume; PE; peak enhancement; post-radiotherapy; post-RT; pre-radiotherapy; pre-RT; PSV; radiotherapy; region of interest; ROI; RT; time-to-peak; TTP; Adipose Tissue; Adult; Aged; Aged, 80 and over; Contrast Media; Feasibility Studies; Female; Humans; Magnetic Resonance Angiography; Male; Middle Aged; Nasopharyngeal Neoplasms; Neoplasm Staging; Organ Sparing Treatments; Parotid Gland; Prognosis; Radiotherapy Dosage; Radiotherapy, Conformal; Retrospective Studies; Treatment Outcome
Type
journal article