Novel eradicative high-dose rate brachytherapy for internal mammary lymph node metastasis from breast cancer

Table 1 Calculated skin dose

Skin		Epidermis	Dermis	Subdermis
Reference point	Depth from the skin surface (mm)	0.1	2.5	5
EBRT	Dose (cGy)	36	48	54
	Equivalent dose* - a	40	48	57.1
BT without spacer	Dose (cGy)	9.3	8	12.5
	Equivalent dose* - b	22.9	17.6	41.6
	Cumulative dose of a + b	62.9	65.6	98.7
BT with spacer	Dose (cGy)	1.8	4.4	6.7
	Equivalent dose* - c	1.73	6.51	12.9
	Cumulative dose of a + c	41.73	54.51	70
Ratio of dose reduction in equivalent dose*: c/b	EQD2, α/β = 3 (cGy)	1/13.2	1/2.7	1/3.22

EBRT: External beam radiotherapy; BT: Brachytherapy.