Table 2 Imaging biomarkers for disease characterisation (semi-quantitative and quantitative) with examples of current evidence for their use that would support decision-making
Biomarker | SemiQ/Q | Disease | Question answered | Utility of biomarker | Data from | Potential decision for | |
|---|---|---|---|---|---|---|---|
Non-malignant disease | Young’s modulus | Q | Coronary plaques [53] | Risk of rupture | Reproducibility CoV 22% vessel wall, 19% in plaque. AUC for focal neurology Youngs modulus + degree = 0.78 | Single centre | Stenting, coronary bypass surgery |
Plaque density, vessel luminal diameter | Q | Coronary artery stenosis | Risk of plaque rupture; risk of significant cardiac ischaemia, infarction, death | No luminal narrowing but with coronary artery calcium (CAC) score > 0 had a 5-year mortality HR 1.8 compared with those whose CACS = 0. No luminal narrowing but CAC ≥ 100 had mortality risks similar to individuals with non-obstructive coronary artery disease [138] CT angiography significantly better at predicting events than stress echo/ECG [68] Coronary death/non-fatal myocardial infarction was lower in patients with stable angina receiving CT angiography than in the standard-care group (HR = 0.59) [69] | Multicentre Multicentre Multicentre | Statins, stenting, coronary bypass surgery | |
18F-Na | SQ | Aortic valve disease Coronary plaque [139] Acute events from abdominal aortic aneurysm | Valve stenosis present Likelihood of plaque rupture Likelihood of aneurysm rupture | Reproducibility NaF uptake 10% [140] Baseline 18F-NaF uptake correlated closely with the change in calcium score at 1 year [141] 18F-NaF uptake (maximum tissue-to-background ratio 1·90 [IQR 1.61–2.17]) associated with ruptured plaques and those with high-risk features [142] Aneurysms in the highest tertile of 18F-NaF uptake expanded 2.5× more rapidly than those in the lowest tertile and were 3× more likely to rupture [143] | Single Multicentre | Coronary stenting, aneurysm stenting | |
MTR | Q | Multiple sclerosis | Disease progression | MTR significantly correlates with T2 lesion volume [144] Grey matter MTR histogram peak height and average lesion MTR percentage change after 12 months independent predictors of disability worsening at 8 years [145] Change in brain MTR specificity 76.9% and PPV 59.1% for Expanded Disability Status Scale score deterioration [146] | Multicentre Single centre Single centre | Timing of therapeutic intervention | |
Malignant disease | 18 FDG-SUV | Q | Cancer Oesophageal cancer | Good or poor prognosis tumour in terms of PFS and OS | Wide variation between individuals and tumours [147] Oesophageal cancer HR 1.86 for OS, 2.52 for DFS [148] | Meta-analysis | Neoadjuvant or adjuvant therapy or treatment modality combinations |
18FLT-SUV | Q | Cancer | High proliferative activity present | Sizeable overlap in values with normal proliferating tissues [75] | Review of data from single centre studies | Neoadjuvant or adjuvant therapy or treatment modality combinations | |
ADC MRF (ADC, T1 and T2) | Q Q Q | Cancer, correlates with tumour grade | Risk of recurrence or metastasis | Area under ROC, sensitivity and specificity of nADCmean for G3 intrahepatic cholangiocarcinoma versus G1+G2 were 0.71, 89.5% and 55.5% [149] “Unfavourable” ADC in cervix cancer predictive of disease-free survival (HR 1.55) [150] ADC and T2 together give AUC of 0.83 for separating high- or intermediate-grade from low-grade prostate cancer [151] | Single centre Meta-analysis Single centre | Need of biopsy or other invasive diagnosis Neoadjuvant or adjuvant therapy Decision for radical treatment or active surveillance | |
DSC-MRI | SQ (rCBV) | Brain cancer | Grading glioma | AUC = 0.77 for discriminating glioma grades II and III [152] | Meta-analysis | Type and time of intervention/treatment | |
APT | Q | Glioma | Proliferation | APT correlates with tumour grade and Ki67 index [153] | Single centre | Therapeutic strategies | |
DCE-CT parameters Blood flow, permeability | Q | Rectal cancer Lung cancer | Blood flow 75% accuracy for detecting rectal tumours with lymph node metastases [154] CT permeability predicted survival independent of treatment in lung cancer [155] | Single centre Single centre | Surgical dissection, adjuvant radiotherapy Adjuvant therapy | ||
DCE-MRI parameters | Q | Cervix cancer Endometrial cancer Rectal cancer Breast cancer | Risk of recurrence or metastasis, survival | Tumour volume with increasing signal is a strong independent prognostic factor for DFS and OS in cervical cancer [156] Low tumour blood flow and low rate constant for contrast agent intravasation (kep) associated with high-risk histological subtype in endometrial cancer [157] Ktrans, Kep and Ve significantly higher in rectal cancers with distant metastasis [158] Ktrans, iAUCqualitative and ADC predict low-risk breast tumors (AUC of combined parameters 0.78) | Single centre Single centre Single centre Single centre | Neoadjuvant, adjuvant or multimodality treatment strategies | |
Radiomic signature [159] | Q | Tumour with good or poor prognosis | Data endpoints, feature selection techniques and classifiers were significant factors in affecting predictive accuracy in lung cancer [162] Radiomic signature (24 selected features) is significantly associated with LN status in colorectal cancer [163] | Single centre Single centre | Neoadjuvant or adjuvant treatment, immunotherapy Lymph node dissection, adjuvant treatment |