TLG-S criteria are superior to both EORTC and PERCIST for predicting outcomes in patients with metastatic lung adenocarcinoma treated with erlotinib.
OBJECTIVE
In this retrospective review of prospectively collected data, we sought to investigate whether early FDG-PET assessment of treatment response based on total lesion glycolysis measured using a systemic approach (TLG-S) would be superior to either local assessment with EORTC (European Organization for Research and Treatment of Cancer) criteria or single-lesion assessment with PERCIST (PET Response Criteria in Solid Tumors) for predicting clinical outcomes in patients with metastatic lung adenocarcinoma treated with erlotinib. We also examined the effect of bone flares on tumor response evaluation by single-lesion assessment with PERCIST in patients with metastatic bone lesions.


METHODS
We performed a retrospective review of prospectively collected data from 23 patients with metastatic lung adenocarcinoma treated with erlotinib. All participants underwent FDG-PET imaging at baseline and on days 14 and 56 after completion of erlotinib treatment. In addition, diagnostic CT scans were performed at baseline and on day 56. FDG-PET response was assessed with TLG-S, EORTC, and PERCIST criteria. Response assessment based on RECIST 1.1 (Response Evaluation Criteria in Solid Tumors) from diagnostic CT imaging was used as the reference standard. Two-year progression-free survival (PFS) and overall survival (OS) served as the main outcome measures.


RESULTS
We identified 13 patients with bone metastases. Of these, four (31 %) with persistent bone uptake due to bone flares on day 14 were erroneously classified as non-responders according to the PERCIST criteria, but they were correctly classified as responders according to both the EORTC and TLG-S criteria. Patients who were classified as responders on day 14 based on TLG-S criteria had higher rates of 2-year PFS (26.7 % vs. 0 %, P = 0.007) and OS (40.0 % vs. 7.7 %, P = 0.018). Similar rates were observed in patients who showed a response on day 56 based on CT imaging according to the RECIST criteria. Patients classified as responders on day 14 according to the EORTC criteria on FDG-PET imaging had better rates of 2-year OS than did non-responders (36.4 % vs. 8.3 %, P = 0.015).


CONCLUSIONS
TLG-S criteria may be of greater help in predicting survival outcomes than other forms of assessment. Bone flares, which can interfere with the interpretation of treatment response based on PERCIST criteria, are not uncommon in patients with metastatic lung adenocarcinoma treated with erlotinib.
Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan.|Department of Nuclear Medicine and Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital and Chang Gung University, 5 Fu-Shin Street, Kueishan, Taoyuan, 333, Taiwan.
Kung-Chu
KC
Ho
Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.
Yu-Hua Dean
YD
Fang
Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan.
Hsiao-Wen
HW
Chung
Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
Yuan-Chang
YC
Liu
Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
John Wen-Cheng
JW
Chang
Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
Ming-Mo
MM
Hou
Department of Thoracic Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
Cheng-Ta
CT
Yang
Department of Nuclear Medicine and Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital and Chang Gung University, 5 Fu-Shin Street, Kueishan, Taoyuan, 333, Taiwan.
Nai-Ming
NM
Cheng
Department of Nuclear Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan.
Tzu-Pei
TP
Su
Department of Nuclear Medicine and Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital and Chang Gung University, 5 Fu-Shin Street, Kueishan, Taoyuan, 333, Taiwan. yen1110@adm.cgmh.org.tw.
Tzu-Chen
TC
Yen
D000230:Adenocarcinoma / Q000175:diagnosis / Q000188:drug therapy* / Q000556:secondary*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage; D000069347:Erlotinib Hydrochloride / Q000008:administration & dosage*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000592:standards; D049268:Positron-Emission Tomography / Q000379:methods / Q000592:standards; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D066066:Response Evaluation Criteria in Solid Tumors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000069347:Erlotinib Hydrochloride
Erlotinib; FDG-PET; Lung cancer; Outcomes; Survival; Tumor response