A prospective study of DWI, DCE-MRI and FDG PET imaging for target delineation in brachytherapy for cervical cancer

Radiother Oncol. 2016 Sep;120(3):519-525. doi: 10.1016/j.radonc.2016.08.002. Epub 2016 Aug 12.


Background and purpose: We examined the utility of dynamic contrast-enhanced MRI (DCE-MRI), diffusion-weighted MRI (DWI), and FDG-PET imaging for brachytherapy target delineation in patients with locally advanced cervical cancer.

Materials and methods: Twenty-two patients had DWI, DCE-MRI, and FDG-PET/CT scans after brachytherapy applicator insertion, in addition to standard T2-weighted (T2w) 3T MRI. Gross tumor volume (GTVB) and high-risk clinical target volume (HRCTV) were contoured first on T2w images, and then modified if indicated upon review of DWI/DCE-MRI/FDG-PET images by two observers. The primary endpoint was utility, determined by the number of patients whose volumes were modified, and interobserver variability.

Results: Eleven patients' T2w-GTVB were modified based on DWI/DCE-MRI/FDG-PET by observer 1, due to clearer demarcation (7) and residual disease not well visualized on T2w MRI (4). GTVB was modified in 17 patients by observer 2 (11 and 6, respectively). Incorporation of functional imaging improved the conformity index (CI) for GTVB from 0.54 (T2w alone) to 0.65 (P=0.003). HRCTV was modified in 3 and 8 patients by observers 1 and 2, respectively, with a trend toward higher CI using functional imaging (0.71 to 0.76, P=0.06).

Conclusions: DWI/DCE-MRI/FDG-PET imaging as a supplement to T2w MRI decreased interobserver variability in GTVB delineation.

Keywords: Brachytherapy; Cervical cancer; Diffusion-weighted MRI; Dynamic contrast-enhanced MRI; FDG PET; Target delineation.

MeSH terms

  • Adult
  • Aged
  • Brachytherapy / methods*
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Image Interpretation, Computer-Assisted
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Neoplasm, Residual
  • Observer Variation
  • Positron Emission Tomography Computed Tomography
  • Positron-Emission Tomography
  • Prospective Studies
  • Radiotherapy, Image-Guided / methods*
  • Uterine Cervical Neoplasms / diagnostic imaging*
  • Uterine Cervical Neoplasms / pathology
  • Uterine Cervical Neoplasms / radiotherapy*


  • Fluorodeoxyglucose F18