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

OncoTargets and Therapy Dovepress open access to scientific and medical research Original Research Open Access Full Text Article F-fluorodeoxyglucose positron emission tomography predicts lymph node responses to definitive chemoradiotherapy in esophageal squamous cell carcinoma patients OncoTargets and Therapy downloaded from https://www.dovepress.com/ by 37.59.46.207 on 21-Dec-2018 For personal use only. 18 This article was published in the following Dove Press journal: OncoTargets and Therapy Wenyao Zhu 1,2 Yan Zhang 2 Li Kong 2 Yong Huang 3 Jinsong Zheng 3 Renben Wang 2 Minghuan Li 2 Jinming Yu 2 School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan, Shandong, China; 2Department of Radiation Oncology and Radiology, Shandong Cancer Hospital Affiliated to Shandong University, Jinan, Shandong, China; 3Department of Nuclear Medicine, Shandong Cancer Hospital Affiliated to Shandong University, Jinan, Shandong, China 1 Purpose: To evaluate the capability of 18F-fluorodeoxyglucose positron emission tomography/ computed tomography (18F-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 18F-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 18F-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. Keywords: 18F-FDG-PET/CT, esophageal squamous cell carcinoma, radiotherapy, lymph node, response, radiation dose, personalized radiation dose Introduction Correspondence: Jinming Yu; Minghuan Li Department of Radiation Oncology and Radiology, Shandong Cancer Hospital Affiliated to Shandong University, 440 Jiyan Road, Jinan 250117, Shandong, China Tel +86 531 86762 6782 Fax +86 531 8798 4079 Email ; 4345 submit your manuscript | www.dovepress.com OncoTargets and Therapy 2018:11 4345–4353 Dovepress © 2018 Zhu et al. This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php). http://dx.doi.org/10.2147/OTT.S160456 Powered by TCPDF (www.tcpdf.org) Esophageal cancer (EC) is one of the common malignancies and causes of cancer deaths worldwide.1 Esophageal squamous cell carcinoma (ESCC) is the predominant histological type of EC worldwide, especially in Asia.2 At present, the standard care for the locally advanced unresectable ESCC is definitive chemoradiotherapy (dCRT).3,4 According to the results of the RTOG 90-12 study and INT0123 trial, dose escalation from 50.4 to 64.8 Gy did not improve the overall survival (OS) and pathological complete response (pCR), but increased the toxicity. The National Comprehensive Cancer Network guidelines recommended a radiation dose of 50.4 Gy to patients with ESCC for dCRT.5–7 Dovepress OncoTargets and Therapy downloaded from https://www.dovepress.com/ by 37.59.46.207 on 21-Dec-2018 For personal use only. Zhu et al Previous studies have suggested that response of lesions (primary tumor and metastatic lymph nodes [mLNs]) is a major determinant of recurrence and survival for patients with ESCC.8–10 Lin et al found the pCR can predict OS (48.2 vs 19.7 months) and disease-free survival (31.1 vs 6.1 months) in patients treated with dCRT.11 Most of the studies on ESCC have focused on the primary tumor and indicated that escalated dose failed to improve local control (LC) or survival.5,6,12 However, only little attention has been paid to mLN, although recent studies have indicated response of mLN is a novel prognostic factor for ESCC.13 For nodal lesions, a higher radiation dose may lead to a better response compared with the standard dose of 50.4 Gy based on the theory of radiation biology, which may confer a better prognosis.14 In addition, the advanced radiotherapy technologies, such as simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) techniques, allow selectively increasing the dose to partial lesions, while sparing the normal tissues and subclinical lesions.15,16 The challenge is to correctly identify the involved node which can gain a better response from the escalated dose before dCRT. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) parameters including maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) may be promising biomarkers to predict the response of lesions and prognosis in patients with ESCC.17–19 The major aim of the present study is to evaluate the relationship between 18F-fluorodeoxyglucose (FDG) metabolic level and response of mLNs that received different irradiation doses. Our study may guide personalized radiation dose to mLN for a better outcome. To our knowledge, this has not been studied previously. defined according to the criteria of the American Joint Committee on Cancer. dCRT Radiotherapy (RT) was delivered as either 3-dimensional conformal RT or IMRT with high-energy linear accelerators. Radiation was given at a dose of 1.8 or 2 Gy once daily for 5 days/week up to a total dose of 50.4–68.4 Gy to lesions (primary tumor and mLNs). The primary tumor and mLNs were contoured as gross tumor volume – tumor (GTVt) and gross tumor volume – nodes (GTVn), respectively. Clinical tumor volume (CTV, including CTVt and CTVn) was defined as GTV plus a 3.0 cm margin superior and inferior to the primary tumor, and a (...truncated)