Table 2 Van Herk’s parameters for crawl couch margin calculation in the comparative versus the validation group (in mm).
From: Crawl positioning improves set-up precision and patient comfort in prone whole breast irradiation
Patient | AP | LL | CC | ||||||
|---|---|---|---|---|---|---|---|---|---|
Comparative | Validation | All | Comparative | Validation | All | Comparative | Validation | All | |
Group systematic error (M) | − 0.2 | 1.7 | 1.4* | − 0.8 | − 0.3 | − 0.5 | − 1.9 | − 0.2 | − 0.5 |
Group systematic error SD (Σ) | 3.3 | 2.9 | 3.1 | 2.5 | 3.6 | 3.4* | 5.7 | 3.3 | 3.9* |
Root mean square of SD’s (σ) | 3.1 | 3.5 | 3.4 | 2.8 | 4.5 | 4.2* | 3.1 | 3.5 | 3.4 |
Required margins (mm) | 11 | 10 | 10 | 8 | 12 | 11 | 16 | 11 | 12 |
