Table 3.

Measured setup errors (fractions 1–5), residual setup errors (fractions 6–10), and number of corrections of the $\text{FVCP}-{\text{FAL}}_{2.5\text{mm}}$ protocol applied in WBRT‐LN $(\mathrm{N}=20)$

	AP		ML		SI
	No Offline Correction	FVCP	No Offline Correction	FAL	No Offline Correction	FAL
Threshold Σ (mm)	–	0.0	–	2.5	–	2.5
${\mu }_{\mathrm{P}}$ (mm)	$-5.8$	0.5	$-0.6$	$-0.4$	1.8	$-0.3$
${\mathrm{\Sigma }}_{\mathrm{P}}$ (mm)	6.0	2.0	2.9	1.3	2.5	2.7
${\sigma }_{\mathrm{P}}$ (mm)	5.1	3.0	2.7	2.8	3.0	3.1
PTV (mm)	19	7	9	5	8	9
Number of corrections	0	20	0	11	0	7

$\text{FVCP}-{\text{FAL}}_{2.5\text{mm}}=$ fixed vertical couch position – fixed‐action–level protocol with 2.5 mm correction threshold; $\text{WBRT}-\text{LN}=$ whole‐breast radiotherapy with additional lymph node irradiation; $\text{AP}=$ anteroposterior; $\text{ML}=$ mediolateral; $\text{SI}=$ superior‐inferior; ${\mu }_{\mathrm{P}}=$ population mean setup error; ${\mathrm{\Sigma }}_{\mathrm{P}}=$ systematic setup error; ${\sigma }_{\mathrm{P}}=$ random setup error; $\text{PTV}=$ planning target volume.