Posttreatment FDG-PET Uptake in the Supraglottic and Glottic Larynx Correlates With Decreased Quality of Life After Chemoradiotherapy

Abstract

Purpose-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 post-therapy FDG PET imaging. We sought to determine if 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 IMRT and free of recurrence at one year were studied. FDG-PET imaging was obtained at 3 and 12 months post-treatment. 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 one year after therapy. A one-tailed Pearson correlation test was used to examine associations between SUV levels and functional outcome measures.Results-SUV levels in the supraglottic and glottic larynx from FDG PET imaging obtained 12 months post-treatment were inversely associated with quality of life measures and were correlated with a more restricted diet one 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.Conclusion-Altered metabolism in irradiated tissues persists one year after therapy. FDG PET scans may be used to assess normal tissue damage following chemoradiotherapy. These data support investigating hypermetabolic conditions associated with inflammation and\or oxidative stress as causal agents for radiation induced normal tissue damage.

Clinical Significance of Postradiotherapy [18F]-Fluorodeoxyglucose Positron Emission Tomography Imaging in Management of Head-and-Neck Cancer—A Long-Term Outcome Report

“…This was likely because of RT-induced inflammatory changes in the larynx. We have shown that persistent FDG uptake in the glottic and supraglottic larynx correlates with decreased quality of life after chemoradiotherapy (10). The greater standardized uptake value in the glottic and supraglottic larynx at 12 months after RT inversely correlated with all domains of quality of life, including eating, speech, aesthesis, and social function.…”

“…We have also presented several reports on the use of FDG-PET in the decision making for neck dissection after definitive RT (6)(7)(8)(9) and the correlation of FDG uptake with patients' quality of life (10). In the present report, we have updated our experience with FDG-PET obtained after RT in a large cohort of patients and long-term follow-up.…”

18F-FDG PET as a Routine Posttreatment Surveillance Tool in Oral and Oropharyngeal Squamous Cell Carcinoma: A ProspectiveStudy

“…18 F-FDG PET performed within 10 wk after radiation or chemoradiation has been associated with high rates of false-negative findings due to a time period of decreased 18 F-FDG uptake after chemoradiation, despite the ongoing presence of viable tumor cells (19). Falsepositive findings, which are attributed to nonspecific mucosal changes due to chemoradiation, are also associated with 18 F-FDG PET performed too early after treatment (20). In addition, the efficacy of chemoradiotherapy (the tumor-kill phenomenon) cannot be fully assessed for at least 8-10 wk after completing chemoradiation.…”

PET Monitoring of Therapy Response in Head and Neck Squamous Cell Carcinoma

“…Although the PPV of PET after chemoradiotherapy is relatively low, most scans will in fact have negative findings when interpreted properly. However, true prolonged, intense 18 F-FDG uptake after definitive therapy indicates a poor treatment outcome or treatment-related complications: In an interesting study on patients with laryngeal cancer treated with intensity-modulated radiotherapy, Dornfeld et al (80) showed an inverse relationship between the intensity of (persistent) 18 F-FDG uptake at 12 mo after treatment and quality of life, the ability to speak, and the ability to swallow solid foods. In other words, persistent 18 F-FDG uptake indicates either persistent disease or persistent treatmentinduced structural and functional damage to the larynx.…”