Timing and intensity of changes in FDG uptake with symptomatic esophagitis during radiotherapy or chemo-radiotherapy.
OBJECTIVE
To study whether esophageal FDG activity changes by time of mid-course of fractionated radiotherapy (RT), and whether these changes are associated with radiation esophagitis in patients with non-small cell lung cancer (NSCLC).


METHODS
Fifty patients with stage I-III NSCLC were enrolled prospectively and, all received ≥60 Gy RT. FDG-PET/CT scans were acquired prior to, and during-RT after delivery of 45 Gy. Normalized standardized uptake values (NSUV), defined by the esophageal maximum SUV relative to intravascular background level in the aortic arch, were sampled in the esophagus at the level of the primary tumor, sternal notch, aortic arch, carina, and gastro-esophageal junction. Symptomatic radiation esophagitis was defined as an event.


RESULTS
Compared to baseline, esophageal NSUV increased significantly during-RT at the level of the primary tumor (1.09 ± 0.05 vs.1.28 ± 0.06, p = 0.001), but did not change at other levels in the esophagus. 16 patients had radiation esophagitis events and these patients had significantly higher during-RT to baseline NSUV ratios than those without esophagitis (1.46 ± 0.12, 95% CI 1.20-1.71; vs. 1.11 ± 0.05, 95% CI 1.01-1.21, p = 0.002). Maximum esophageal dose (p = 0.029), concurrent chemotherapy (p = 0.022) and esophageal FDG PET NSUV ratio (during-RT to baseline, p = 0.007), were independent factors associated with esophagitis and area under curves (AUC) were 0.76, 0.70 and 0.78, respectively. Combining esophageal maximum dose and FDG PET NSUV Ratio at the tumor level increased AUC to 0.85 (p = 0.016).


CONCLUSIONS
FDG uptake increased in esophagus during-RT and this increase may predict radiation esphagitis during later course of treatment.
Shuanghu Tiger
ST
Yuan
Richard K J
RK
Brown
Lujun
L
Zhao
Randall K
RK
ten Haken
Milton
M
Gross
Kemp B
KB
Cease
Matt
M
Schipper
Paul
P
Stanton
Jinming
J
Yu
Department of Radiation Oncology, University of Michigan, 1500 E, Medical Center Drive, Ann Arbor, MI 48109, USA. fengkong@gru.edu.
Feng-Ming Spring
FM
Kong
D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D019540:Area Under Curve; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000532:radiotherapy; D059248:Chemoradiotherapy; D004941:Esophagitis / Q000209:etiology*; D004947:Esophagus / Q000187:drug effects / Q000528:radiation effects; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011832:Radiation Injuries / Q000209:etiology*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D019788:Fluorodeoxyglucose F18