FDG-PET assessment of the effect of head and neck radiotherapy on parotid gland glucose metabolism.

Published

Journal Article

PURPOSE: Functional imaging with [F-18]-fluorodeoxyglucose positron emission tomography (FDG-PET) provides the opportunity to define the physiology of the major salivary glands before and after radiation therapy. The goal of this retrospective study was to identify the radiation dose-response relationship of parotid gland glucose metabolism in patients with head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: Forty-nine adults with HNSCC were identified who had curative intent intensity-modulated radiation therapy (IMRT) and FDG-PET imaging before and after treatment. Using a graphical user interface, contours were delineated for the parotid glands on axial CT slices while all authors were blinded to paired PET slices. Average and maximal standard uptake values (SUV) were measured within these anatomic regions. Changes in SUV and volume after radiation therapy were correlated with parotid gland dose-volume histograms from IMRT plans. RESULTS: The average parotid gland volume was 30.7 mL and contracted 3.9 ± 1.9% with every increase of 10 Gy in mean dose (p = 0.04). However, within the first 3 months after treatment, there was a uniform reduction of 16.5% ± 7.3% regardless of dose. The average SUV(mean) of the glands was 1.63 ± 0.48 pretreatment and declined by 5.2% ± 2.5% for every increase of 10 Gy in mean dose (p = 0.04). The average SUV(max) was 4.07 ± 2.85 pretreatment and decreased in a sigmoid manner with mean dose. A threshold of 32 Gy for mean dose existed, after which SUV(max) declined rapidly. CONCLUSION: Radiation dose responses of the parotid glands can be measured by integrated CT/FDG-PET scans. Retrospective analysis showed sigmoidal declines in the maximum metabolism but linear declines in the average metabolism of the glands with dose. Future studies should correlate this decline in FDG uptake with saliva production to improve treatment planning.

Full Text

Duke Authors

Cited Authors

  • Roach, MC; Turkington, TG; Higgins, KA; Hawk, TC; Hoang, JK; Brizel, DM

Published Date

  • January 2012

Published In

Volume / Issue

  • 82 / 1

Start / End Page

  • 321 - 326

PubMed ID

  • 21030160

Pubmed Central ID

  • 21030160

Electronic International Standard Serial Number (EISSN)

  • 1879-355X

International Standard Serial Number (ISSN)

  • 0360-3016

Digital Object Identifier (DOI)

  • 10.1016/j.ijrobp.2010.08.055

Language

  • eng