Table 1.
Overview of studies regarding the differentiation of radiation-induced changes from brain metastasis recurrence using FDG PET
| Chao et al, 200177 | Belohlavek et al, 200378 | Chernov et al, 200575 | Horky et al, 201172 | Lai et al, 201574 | Hatzoglou et al, 201676 | Tomura et al, 201773 | |
|---|---|---|---|---|---|---|---|
| Patients, n | 32 | 25 | 9 | 25 | 14 | 24 | 15 |
| Lesions, n | 36 | 57 | 9 | 27 | 14 | 26 | 18 |
| Recurrent metastases, n | 18 | 8 | 4 | 16 | 6 | 11 | 10 |
| Radiation-induced changes, n | 18 | 49 | 5 | 11 | 8 | 15 | 8 |
| Histological confirmation of diagnosis | 36% | 5% | 56% | na | 100% | 23% | 56% |
| FDG PET method | 20 min static scan, 45–60 min p.i. | 15 min static scan, 35–40 min p.i. | na | dual phase PET; median time between early and late scan, 3.8 h | static scan 60 min p.i., scan duration na | 10 min static scan, 60 min p.i. | static scan 60 min p.i., scan duration na |
| Additional imaging method | no | no | MRS | no | ASL | DCE PWI | DWI MET PET |
| Sensitivity | 65% | 75% | 50% | 95% | 83% | 82% | 40% |
| Specificity | 80% | 94% | 80% | 100% | 75% | 80% | 50% |
| Accuracy | na | 91% | 67% | 96% | 79% | na | na |
| Threshold (TBRmean) | visually | visually | visually | change of L/GM ratios > 0.19 over time | 3.0 (SUVmax) | 1.4 (TBRmax) | 0.97 (TBRmax) |
| Performance of FDG PET compared with other imaging method(s) | na | na | inferior | na | inferior | inferior | inferior |
ASL = arterial spin labeling; DCE PWI = dynamic contrast-enhanced perfusion-weighted imaging; DWI = diffusion-weighted imaging; FDG = 18F-2-fluoro-2-deoxy-D-glucose; L/GM = lesion to gray matter ratio; MET = 11C-methyl-L-methionine; na = not available; MRS = single- and multi-voxel proton MR spectroscopy; p.i. = post-injection; TBRmean/max = mean or maximum standardized uptake value of the lesion divided by the maximum standardized uptake value of the reference region; SUVmax = maximum standardized uptake value