Role of diffusion-weighted echo-planar MR imaging in differentiation of residual or recurrent head and neck tumors and posttreatment changes

AJNR Am J Neuroradiol. Jun-Jul 2007;28(6):1146-52. doi: 10.3174/ajnr.A0491.

Abstract

Background and purpose: The purpose of this work was to evaluate whether diffusion-weighted MR imaging can be used in differentiating residual or recurrent head and neck tumors from postoperative or postradiation changes.

Materials and methods: This study included 32 patients clinically suspected for recurrent head and neck tumor after surgery (n=3), radiation therapy (n=13), or both (n=16). Diffusion-weighted MR imaging was done by using a single-shot spin-echo echo-planar sequence. The apparent diffusion coefficient (ADC) value of the suspected lesion was calculated and correlated with pathologic results.

Results: Adequate diffusion-weighted MR images and ADC maps were obtained in 30 patients (93.8%). The mean ADC value of residual or recurrent lesions (1.17 +/- 0.33 x 10(-3) mm(2)/s) was less than that of posttherapeutic changes (2.07 +/- 0.25 x 10(-3) mm(2)/s), and the difference was statistically significant (P<.001). When an ADC value of 1.30 x 10(-3) mm(2)/s was used as a threshold value for differentiation, the best results were obtained with an accuracy of 87%, sensitivity of 84%, specificity of 90%, positive predictive value of 94%, and negative predictive value of 76%.

Conclusions: Diffusion-weighted MR imaging with ADC measurement has promising results for differentiating residual or recurrent head and neck tumors from postoperative or postradiation changes.

MeSH terms

  • Aged
  • Diagnosis, Differential
  • Diffusion Magnetic Resonance Imaging / methods*
  • Echo-Planar Imaging / methods*
  • Female
  • Head and Neck Neoplasms / diagnosis*
  • Head and Neck Neoplasms / surgery*
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / diagnosis*
  • Neoplasm Recurrence, Local / prevention & control*
  • Prognosis
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Treatment Failure
  • Treatment Outcome