EGFR and neoplasm: Compared with clinical examinations such as direct sequencing of PCR-amplified genomic DNA, high-resolution melting analysis, fragment analysis, and the amplification refractory mutation system32, which are generally expensive and sometimes do not have a high rate of tumor cell detection, radiological features can not only discriminate EGFR-mutated subtypes (exon 19 deletion and exon 21 mutation) but are noninvasive and less expensive, especially for advanced NSCLC patients who cannot receive biopsy33.