Insight into the main retrieved findings
| Study (study type) | Follow-up time (sample size) | Main results | Direct conclusions |
|---|---|---|---|
| Pre-treatment LNs evaluation | |||
| Vandecaveye et al. [28] (Prospective) | Not applicable (33 patients) | ADC values are significantly lower for metastatic LNs than for benign ones | LN > 1 cm: ADC > TSE evaluation to select benign LNsLN < 1 cm: ADC showed higher sensitivity but slightly lower specificity |
| Perrone et al. [32] (Retrospective) | Not applicable (32 patients) | A statistically significant relationship exists between DWI and ADC findings, as well as the nodal status | DW acquisitions would be an asset in both identifying pre-treatment nodal status and in evaluating treatment response. Not stratified patients/histology |
| Nakamatsu et al. [30] (Retrospective) | Not applicable (24 patients) | A statistically significant relationship exists between DWI and ADC findings, as well as the nodal status | DW acquisitions would be an asset in both identifying pre-treatment nodal status and in evaluating treatment response. Not stratified patients/histology |
| Taha Ali [16] (Prospective) | Not applicable (34 patients) | Correlation between ADC values and LN status | ADC values alone offer no statistically significant information concerning the grade of LN metastasis |
| Hauser et al. [36] (Retrospective) | 13.5 months (15 patients) | Benign LNs had significant ADC values compared to malignant ones, and the ADC values of metastatic LNs were significantly higher than those of LNs affected by lymphoma | The ADC values of LNs affected by well-differentiated metastasis were then significantly higher than those of LNs with poorly differentiating metastasis. (similar conclusion of vandecaveve, but with a different sample) |
| Heusch et al. [33] (Retrospective) | Not applicable (18 patients) | No significant difference in diagnostic accuracy concerning nodal status between 18FDG-PET/CT and 18FDG-PET-MRI, nor between 18FDG-PET/CT and 18FDG-PET-MRI + DWI | US has greater diagnostic accuracy compared to 18FDG-PET/CT, but not compared to 18FDG-PET/CT and 18FDG-PET-MRI + DWI. The addition of DWI to the diagnostic process significantly improves the detection of metastases in normal-sized LN |
| Stecco et al. [38] (Retrospective) | 15 months (25 patients) | Using both DW-MRI and PET/CT increases the diagnostic value of T and N parameters | DW-MRI and PET/CT must be combined for the HNSCC work-up |
| Jin et al. [39] (Prospective) | Not applicable (65 patients) | A statistical correlation does exist between mean ADC values of cervical LN and their benign or metastatic nature | |
| Park et al. [31] (Retrospective) | Not applicable (36 patients) | Several features from the first- and second-order whole lesion volumetric texture analysis of ADC data using msEPI-DWI were significantly different between metastatic and benign LNs in HNSCC | TA values providing esteem for complexity, energy, and roundness were significant predictive factors for nodal metastases. Complexity was the single best predictive feature |
| Freihat et al. [40] (Retrospective) | Not applicable (90 patients) | A statistically significant difference does exist between metastatic and normal LNs’ ADC values | |
| Pre-/post-treatment evaluation | |||
| Dirix et al. [29] (Prospective) | Not applicable (22 patients) | The superiority of DWI imaging compared to conventional imaging in nodal staging | DWI imaging best allows us to correctly assess both GTV and CTV of nodal lesions, which in turn allows for a more precisely targeted RT, sparing healthy tissues |
| Lee et al. [12] (Prospective) | Not applicable (22 patients) | Low impact of ADC value cutoff for differentiating benign and malignant LNs | DWI examination provided greater sensitivity and specificity than conventional TSE MRI |
| Hoang et al. [41] (Prospective) | 31 months (16 patients) | Intra-treatment variability in ADC values for metastatic LNs is greater than their baseline variability | Inherent baseline variability should be kept into account to ensure a more accurate evaluation of treatment-induced changes in ADC |
| Chen et al. [37] (Prospective) | < 6 months (35 patients) | ADC increases were significantly larger in responders than in non-responders; however, in patients with NPC, the pre-treatment ADCs of responders to NAC were not significantly lower than those of non-responders | |
| Schouten et al. [34] (Retrospective) | Not applicable (84 patients) | PET/CT recognized all regional residues and DW-MRI recognized most patients with regional control with substantial and moderate observer agreement, respectively | |
| Razek et al. [35] (Retrospective) | Not applicable (43 patients) | Combining TBF and ADC evaluation may yield the best results in evaluating LNs | |
| Anjari et al. [42] (Prospective) | < 6 months (25 patients) | Metastatic LNs have higher TBF and lower ADC values, compared to reactive ones and such differentiation is easier when both techniques are combined | TBF and ADC evaluation may yield the best results in evaluating LN status |
| Connor et al. [43] (Prospective) | Not available (56 patients) | No statistically significant or clinically relevant correlation between DW-MRI and 18FDG-PET scan results 12 weeks after CRT for LNs. Clinically relevant DWI changes for primary tumors response evaluation | Therapy efficacy assessment ADC mean at 12 weeks post-CRT DW-MRI (P = 0.03) and the interval change in nodal ADC min from pre-treatment to 12 weeks post-CRT DW-MRI (P = 0.05) were associated with 2-year DFS |
Reports focused on DWI evaluation. TBF: tumor blood flow; GTV: gross target volume; CTV: clinical target volume; RT: radiotherapy; DFS: disease free survival
