Posttreatment FDG-PET uptake in the supraglottic and glottic larynx correlates with decreased quality of life after chemoradiotherapy.
OBJECTIVE
Inflammation and increased metabolic activity associated with oxidative stress in irradiated normal tissues may contribute to both complications following radiotherapy and increased glucose uptake as detected by posttherapy fluorodeoxyglucose (FDG)-PET imaging. We sought to determine whether increased glucose uptake in normal tissues after chemoradiotherapy is associated with increased toxicity.


METHODS
Consecutive patients with locoregionally advanced head and neck cancers treated with intensity-modulated radiation therapy and free of recurrence at 1 year were studied. FDG-PET imaging was obtained at 3 and 12 months posttreatment. Standardized uptake value (SUV) levels were determined at various head and neck regions. Functional outcome was measured using a quality of life questionnaire and weight loss and type of diet tolerated 1 year after therapy. A one-tailed Pearson correlation test was used to examine associations between SUV levels and functional outcome measures.


RESULTS
Standardized uptake value levels in the supraglottic and glottic larynx from FDG-PET imaging obtained 12 months posttreatment were inversely associated with quality of life measures and were correlated with a more restricted diet 1 year after therapy. SUV levels at 3 months after therapy did not correlate with functional outcome. Increases in SUV levels in normal tissues between 3 and 12 months were commonly found in the absence of recurrence.


CONCLUSIONS
Altered metabolism in irradiated tissues persists 1 year after therapy. FDG-PET scans may be used to assess normal tissue damage following chemoradiotherapy. These data support investigating hypermetabolic conditions associated with either inflammation, oxidative stress, or both, as causal agents for radiation-induced normal tissue damage.
Dornfeld
Ken
K
Department of Radiation Oncology, The Carver College of Medicine, University of Iowa, Iowa City, IA, USA . Kdornfeld@smdc.org
Hopkins
Shane
S
Simmons
Joel
J
Spitz
Douglas R
DR
Menda
Yusuf
Y
Graham
Michael
M
Smith
Russell
R
Funk
Gerry
G
Karnell
Lucy
L
Karnell
Michael
M
Dornfeld
Maude
M
Yao
Min
M
Buatti
John
J
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000532:radiotherapy; D003131:Combined Modality Therapy / Q000009:adverse effects; D004032:Diet; D004435:Eating; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D005931:Glottis / Q000378:metabolism / Q000528:radiation effects; D005947:Glucose / Q000378:metabolism; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000532:radiotherapy; D006304:Health Status; D006801:Humans; D007830:Larynx / Q000378:metabolism / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011788:Quality of Life; D011832:Radiation Injuries / Q000378:metabolism*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose