Standardized uptake value on (18)F-FDG-PET/CT is a predictor of EGFR T790M mutation status in patients with acquired resistance to EGFR-TKIs.
The development of epidermal growth factor receptor (EGFR) T790M point mutation in exon 20 (T790M) is the most common mechanism of resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The purpose of this study was to determine the association of (18)F-2-fluoro-2-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) metrics with T790M status after acquiring resitance to EGFR-TKI resistance.



We retrospectively reviewed 34 advanced non-small cell lung cancer (NSCLC) patients harboring EGFR mutation who underwent rebiopsy and FDG-PET/CT before rebiopsy. These patients were evaluated for baseline characteristics, initial response to EGFR-TKIs, site of rebiopsy, overall survival, and FDG-PET/CT metrics, such as standardized uptake value (SUV), metabolic tumor volume, and total lesion glycolysis of the rebiopsy site.



The median age was 67 years (range, 37-86 years); 19 of the patients (56%) were men. Histologic examination revealed adenocarcinoma in all but one patient, with 20 patients (59%) having stage IIIB and IV disease. Upon initial mutational analyses, the types of EGFR mutation included 17 (50%) deletions in exon 19 and 17 (50%) L858R point mutations in exon 21. At the time of acquired resistance to EGFR-TKIs, T790M mutation was identified in 20 (59%) patients. T790M-positive patients had significantly lower levels of median SUVmean and median SUVmax of the rebiopsy site on FDG-PET/CT, compared with T790M-negative patients (SUVmean: 4.57 vs. 9.91, P=0.0069; SUVmax: 7.26 vs. 16.06, P=0.0054). The survival in patients who acquired T790M after failure of EGFR-TKIs was significantly longer than those without T790M (10.2 mos. vs. 18.6 mos., P<0.05).



T790M status was associated with lower levels of SUVmean and SUVmax on FDG-PET/CT and significantly longer survival.
Department of Thoracic Oncology, Aichi Cancer Center Hospital, Japan. Electronic address: t.yoshida@aichi-cc.jp.
Tatsuya
T
Yoshida
East Nagoya Imaging Diagnosis Center, Japan.
Hirotaka
H
Tanaka
Department of Thoracic Surgery, Aichi Cancer Center Hospital, Japan.
Hiroaki
H
Kuroda
Department of Thoracic Oncology, Aichi Cancer Center Hospital, Japan.
Junichi
J
Shimizu
Department of Thoracic Oncology, Aichi Cancer Center Hospital, Japan.
Yoshitsugu
Y
Horio
Department of Thoracic Surgery, Aichi Cancer Center Hospital, Japan.
Yukinori
Y
Sakao
Department of Diagnostic and Interventional Radiology, Aichi Cancer Center Hospital, Japan.
Yoshitaka
Y
Inaba
East Nagoya Imaging Diagnosis Center, Japan.
Hiroshi
H
Iwata
Department of Thoracic Oncology, Aichi Cancer Center Hospital, Japan.
Toyoaki
T
Hida
Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Japan.
Yasushi
Y
Yatabe
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000379:methods; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D012189:Retrospective Studies
D047428:Protein Kinase Inhibitors; D019788:Fluorodeoxyglucose F18; C512478:EGFR protein, human; D066246:ErbB Receptors
Epidermal growth factor receptor (EGFR); Non-small cell lung cancer (NSCLC); Standardized uptake value (SUV); T790 M