18F-fluorodeoxyglucose positron emission tomography predicts lymph node responses to definitive chemoradiotherapy in esophageal squamous cell carcinoma patients.

PURPOSE

To evaluate the capability of F-fluorodeoxyglucose positron emission tomography/ computed tomography (F-FDG-PET/CT) to predict the clinical response of metastatic lymph node (mLN) to definitive chemoradiotherapy (dCRT) and guide personalized radiation dose in esophageal squamous cell carcinoma (ESCC) patients.

PATIENTS AND METHODS

One hundred and forty-three mLNs from 59 patients with ESCC treated with dCRT and who had undergone a pretreatment F-FDG-PET/CT scan were included in the study. All defined mLNs were contoured by nuclear medicine radiologists. Response was evaluated by contrast-enhanced computed tomography and F-FDG-PET/CT.

RESULTS

Sixty-nine mLNs showed complete response (CR), and 74 mLNs showed non-complete response. The 143 mLNs were divided into 4 groups (Groups 1-4) based on the quartiles of maximum standardized uptake value (SUVmax-G1, SUVmax-G2, SUVmax-G3, and SUVmax-G4) and metabolic tumor volume (MTV-G1, MTV-G2, MTV-G3, and MTV-G4). The CR rate of SUVmax-G2 was significantly higher than the other 3 groups. The escalated radiation dose improved the CR rate of lymph nodes in SUVmax-G3 (55 Gy) and SUVmax-G4 (61 Gy). The lowest CR rate was found in MTV-G4 (the group with the largest MTV). The escalated radiation dose (59.7 Gy) improved the CR rate of lymph node in MTV-Groups 3 and 4.

CONCLUSION

Pretreatment metabolic parameters can predict the response of mLNs to dCRT for patients with ESCC. The parameters could also be used to guide personalized dose to mLNs.