Table 2.

Strength of biomarkers in predicting radiation sensitivity in NSCLC

Types of biomarkers	Outcome predictors	Reference	Strength Category
Panomics
Genomics	Radiosensitiviy Index (RSI)	[64–72]	A
	Genomic-adjusted radiation dose (GARD)	[73]	B
	Lung adenocarcinoma associated gene: KRAS	[114–117]	B
	Squamous cell carcinoma associated genes: KEAP1, NFE2L2	[121]	C
	DNA repair genes: ATM and other mutated genes: PTEN, RB1, TP53 …	[74, 75]	C
SNPs	DNA repair gene sites: XRCC1, BRCA1, and ERCC1 in predicting radiation response	[76–78]	C
	SNPs in predicting radiation related toxicity DNA repair gene sites: ATM, RAD51, XRCC family, LIG4, MTHFR Inflammatory gene sites: TGFβ1 Immune modulated gene sites: CBLB	[79–83] [84–86, 88] [87]	B B C
Epigenetics	unmethylated IGFBP-3 predicting radiation response	[94]	C
	miRNAs level in predicting radiation response	[95–97]	C
Proteome /Metabolome	Serum inflammatory biomarkers in predicting radiation induced toxicity IL-1, KL-6, IL-6, PDGF, TGFα, TGFβ, IL-8 CXCL10 (IP-10), CCL2 (MCP-1), eotaxin, and TIMP-1	[85, 99] [100]	B B
	Mass spectrometry (MS)-based proteomic markers in predicting lung fibrosis C4BPA, VTN, α2M, CO4A, CO5	[101–103]	B
Immunological markers	Serum markers in predicting SABR outcome neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), high neutrophil count	[104]	C
Radiomics
CT scan	Post SABR local recurrence prediction: Enlarging opacity at 12 months after SABR Bulging margin; loss of linear margin, air bronchogram loss	[25–27]	A
	Combined radiomic features in predicting post SABR recurrence and radiadiation	[30–37]	B
	Combined radiomic features in predicting radiation pneumonitis	[38–41]	B
PET	FDG-PET: Max SUV, metabolic volume, total lesion glycolysis in predicting treatment response	[43–47]	A
	FLT-PET change in predicting tumor response	[50–53]	B
	F-MISO PET in predicting radioresistant area for dose escalation	[56–59]	B
Dosiomics	Combined 3D dosiomitc information in prediction GI, GU and lung toxicity	[60, 61]	B

Abbreviations: NSCLC Non-small cell lung cancer. CT Computed tomography. PET Positron emission tomography. SUV Standard uptake volume. SABR Stereotactic ablative radiotherapy. SNP Single nucleotide polymorphisms