Table 1.

List of non-invasive clinical and preclinical imaging techniques for monitoring response to immunotherapy in neuro-oncology studies.

CLINICAL IMAGING TECHNIQUES
Category of imaging technique	Imaging modality	Research or Clinical Practice	Disease in neuro-oncology studies	Immunotherapy category used in neuro-oncology studies	References
Structural	Contrast-enhancing MRI	Clinical practice	GBM, CNS metastases	Vaccine, Cell therapy, Checkpoint blockade, Virus	14, 49
	FLAIR MRI	Clinical practice	GBM, CNS metastases	Vaccine, Cell therapy, Checkpoint blockade, Virus	14, 46, 49
Physiological	DTI MRI	Clinical practice	GBM, CNS metastases	Vaccine, Cell therapy, Checkpoint blockade, Virus	50
	Diffusion kurtosis imaging MRI	Research	GBM	DC vaccine	51
	q-space imaging MRI	Research	Glioma (low grade)	n/a	52
	Neurite orientation dispersion and density index MRI	Research	GBM	n/a	53-55
	DSC MRI	Clinical practice	GBM, CNS metastases	Vaccine, Cell therapy, Checkpoint blockade, Virus	47, 51, 56, 57
	DCE MRI	Clinical practice	GBM, CNS metastases	Vaccine, Cell therapy, Checkpoint blockade, Virus	49
	Arterial spin label MRI	Research	GBM	n/a	49
	PET hypoxia	Research	GBM	n/a	58, 59
Molecular	Amino acid PET	Research	GBM, CNS metastases	Vaccine, Checkpoint blockade	48, 60
	Antibody-based PET	Research	GBM, CNS metastases	n/a	61, 62
	Proliferation PET	Research	GBM, CNS metastases	Vaccine, Checkpoint blockade	63
	PET reporter gene	Research	GBM	Vaccine, Cell therapy, Virus	64-68
	MRS	Research	GBM	Cell therapy	69
Immune cell tracking	PET, MRI, SPECT	Research/Clinical practice	GBM	Vaccine, Cell therapy	70, 71
PRECLINICAL IMAGING TECHNIQUES
Category of imaging technique	Imaging modality	Imaging target	Disease model	Immunotherapy category used in studies	References
Molecular	Antibody-based PET	Effector immune cells proteins	Syngeneic murine colon or mammary carcinoma	Checkpoint blockade	72, 73
	Peptide-based PET	Immune cell cytolytic activity	Syngeneic murine colon carcinoma	Checkpoint blockade	74
	Reporter gene PET	Transgenic T cells	Murine acute myeloid sarcoma	Cell therapy	75
	Reporter gene MRS	Virus-transfected cells	Orthotopic glioma (rat)	Virus	76