Recurrences after intensity modulated radiotherapy for head and neck squamous cell carcinoma more likely to originate from regions with high baseline [18F]-FDG uptake

Radiother Oncol. 2014 Jun;111(3):360-5. doi: 10.1016/j.radonc.2014.06.001. Epub 2014 Jun 30.


Background and purpose: To analyze the recurrence pattern in relation to target volumes and (18)F-fluorodeoxyglucose (FDG) uptake on positron emission tomography in head and neck squamous cell carcinoma (HNSCC) patients treated with definitive chemoradiation.

Material and methods: 520 patients received radiotherapy for HNSCC from 2005 to 2009. Among 100 patients achieving complete clinical response and a later recurrence, 39 patients with 48 loco-regional failures had a recurrence CT scan before any salvage therapy. The estimated point of origin of each recurrence was transferred to the planning CT by deformable image co-registration. The recurrence position was then related to the delineated target volumes and iso-SUV-contours relative to the maximum standard uptake value (SUV). We defined the recurrence density as the total number of recurrences in a sub-volume divided by the sum of that volume for all patients.

Results: 54% (95% CI 37-69%) of recurrences originated inside the FDG-positive volume and 96% (95% CI 86-99%) in the high dose region. Recurrence density was significantly higher in the central target volumes (P<0.0001) and increased with increasing FDG avidity (P=0.036).

Conclusions: The detailed pattern-of-failure data analysis suggests that most recurrences occur in the FDG PET positive areas or the solid tumor.

Keywords: FDG-PET; Head and neck cancer; Pattern of failure; Radiotherapy; Recurrence.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Squamous Cell / diagnostic imaging
  • Carcinoma, Squamous Cell / metabolism*
  • Carcinoma, Squamous Cell / radiotherapy*
  • Fluorodeoxyglucose F18 / pharmacokinetics*
  • Head and Neck Neoplasms / diagnostic imaging
  • Head and Neck Neoplasms / metabolism*
  • Head and Neck Neoplasms / radiotherapy*
  • Humans
  • Multimodal Imaging / methods
  • Neoplasm Recurrence, Local / diagnostic imaging
  • Neoplasm Recurrence, Local / metabolism
  • Positron-Emission Tomography / methods
  • Radiopharmaceuticals / pharmacokinetics*
  • Radiotherapy Planning, Computer-Assisted / methods
  • Radiotherapy, Intensity-Modulated / methods
  • Squamous Cell Carcinoma of Head and Neck
  • Tomography, X-Ray Computed / methods


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18