CBCT-based deformable dose accumulation of external beam radiotherapy in cervical cancer

Figures & data

Table 1. Patient characteristics.

Sample size	10
Median age (years), range	51, 38–74
FIGO Stage: 2	9 (90%)
3	1 (10%)
Histology: adenocarcinoma	2 (20%)
squamous cell carcinoma	7 (70%)
unspecified carcinoma	1 (10%)
Courses of weekly cisplatin [40 mg/m^2]: 4	2 (20%)
5	8 (80%)
Median volume of CTV on MRI [cc], range	228, 149–430
Number of plans in initial library: 2 (non-mover)	6 (60%)
3 (mover)	4 (40%)

Figure 1. (a) Planning CT scan, (b) CBCT scan for same patient, (c) a 50–50 blend of (a) and (b) from rigid registration, (d) CBCT (b) deformed to match planning CT (a) with deformed OAR contours and arrows to indicate direction of movement.

Figure 2. V95% of Ctv_TLR_45_RV for the planned and accumulated dose distributions.

Figure 3. Difference in DVH between planned and accumulated dose distributions for each patient for (a) bladder and (b) rectum. Dashed line indicates mean of magnitude of differences.

Figure 4. Variations in planned, accumulated and summed CBCT D2cc (Gy) for (a) bladder and (b) rectum.

Table 2. Median values of D2cc for the rectum and bladder with range in parentheses.

	Accumulated	Planned - Accumulated	CBCT addition – Accumulated
Bladder D2cc [Gy]	44.9 (43.4, 45.9)	0.8 (−0.1, 2.4)	0.8 (0.4, 2.8)
Rectum D2cc [Gy]	44.8 (43.5, 46.2)	0.3 (−0.9, 2.3)	0.5 (−0.1, 2.3)

Figure 5. Difference between summed CBCT DVHs and accumulated DVHs for (a) bladder and (b) rectum. Dashed line indicates mean of magnitude of differences.

Data availability statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.