Table 1.
Summary of irradiation parameters and outcomes for in vivo studies investigating the FLASH effect in normal tissues (organized in order of model species and targeted tissue, as well as color coded by radiation modality).
| In vivo studies | Irradiation delivery technique | |||||
|---|---|---|---|---|---|---|
| Model | Assay |
FLASH dose modification factor (Bold if >1) |
Total dose (Gy) |
Dose rate (Gy/s) |
Pulse rate (Hz) |
Modality of radiation |
| Zebrafish embryo (16) | Fish length | 1.2–1.5 | 10–12 | 106-107 | Single pulse | Electron |
| Zebrafish embryo (29) | Fish length, survival, and rate of oedema | 1 | 0–43 | 100 | 0.106 ×109 | Proton |
| Whole body irradiation of mice (34) | LD50 | 1.1 | 8–40 | 17–83 | 400 | Electron |
| Thoracic irradiation of mice (10) | TGFβ signaling induction | 1.8 | 17 | 40–60 | 100–150 | Electron |
| Thoracic irradiation of mice (18) | Number of proliferating cells, DNA damage, expression of inflammatory genes |
>1 Significant Differences |
17 | 40–60 | 100–150 | Electron |
| Abdominal irradiation of mice (33) | Survival | <1 Significant Difference |
16 | 35 | Likely 300 | Electron |
| Abdominal irradiation of mice (12) | LD50 | 1.2 | 22 | 70–210 | 100–300 | Electron |
| Abdominal irradiation of mice (17) | Survival, stool formation, regeneration in crypts, apoptosis, and DNA damage in crypt cells |
>1 Significant Differences |
12–16 | 216 | 108 | Electron |
| Whole brain irradiation of mice (25) | Novel object recognition and object location tests |
>1 Significant Differences |
30 | 200, 300 | 108, 180 | Electron |
| Whole brain irradiation of mice (13) | Variety of neurocognitive tests |
>1 Significant Differences |
10 | 5.6·106 | Single pulse | Electron |
| Whole brain irradiation of mice (14) | Novel object recognition test |
>1 Significant Differences |
10 | 30–5.6·106 | 100 or single pulse | Electron |
| Whole brain irradiation of mice (8) | Novel object recognition test | ≥1.4 | 10 | 5.6–7.8·106 | single pulse | Electron |
| Whole brain irradiation of mice (24) | Novel object recognition test |
>1 Significant Difference |
10 | 37 | 1,300 | X-ray |
| Total body and partial body irradiation of mice (32) | TD50 | 1 | 3.6–28 | 37–41 | 1,388 | X-ray |
| Thoracic irradiation of mice (11) | lung fibrosis, skin dermatitis, and survival |
>1 Significant Difference |
15, 17.5, 20 | 40 | ? | Proton |
| Irradiation of mouse tail skin (49) | Necrosis ND50 | 1.4 | 30 and 50 | 17–170 | 50 | Electron |
| Irradiation of mouse skin (27) | Early skin reaction score | 1.1–1.6 | 50–75 | 2.5 mean, 3 ×104 in the pulse | 23–80 | Electron |
| Irradiation of rat skin (26) | Early skin reaction score | 1.4–1.8 | 25–35 | 67 | 400 | Electron |
| Irradiation of mini-pig skin (15) | Skin toxicity | ≥1.4 | 22–34 | 300 | 100 | Electron |