Magnitude and Implications of Interfraction Variations in Organ Doses during High Dose Rate Brachytherapy of Cervix Cancer: A CT Based Planning Study

Table 1

Dose variation in the rectal and bladder doses in mean and 95% confidence intervals of mean.

	Bladder		𝑃 value	Rectum		𝑃 value
	Mean	95% CI		Mean	95% CI
𝐷max	5.04	3.02–7.06	0.65	2.18	1.62–2.74	0.39
𝐷0.1cc	3.21	2.20–4.21	0.82	1.79	1.35–2.22	0.41
𝐷1cc	1.83	1.33–2.34	0.29	1.32	1.01–1.64	0.33
𝐷2cc	1.46	1.05–1.88	0.27	1.16	0.88–1.44	0.28

All values are in Gy. 95% CI: 95% confidence intervals of mean. 𝑃 value is measured for difference in mean doses between two sessions using paired 𝑡-test. 𝐷_max is the maximum point dose for the organ. 𝐷_0.1cc, 𝐷_1cc, and 𝐷_2cc represent the minimum dose to 0.1, 1, and 2 cc volumes, respectively, in the most irradiated tissue adjacent to the applicator.