Experience with Treating Lentigo Maligna with Definitive Radiotherapy

Table 1

Biologically equivalent dose (BED) doses for lentigo maligna.

Total dose (Gy)	No of fractions / weeks of RT	Dose per fraction	BED early	BED late	EQD2  (Gy)	EQD2  (Gy)
60	30/6	2	72	100	60	60
55	25/5	2.25	68.91	98.44	56.15	57.75
50	20/4	2.5	62.5	91.67	52.08	55
45	15/3	3	58.5	90	48.75	54
40	10/2	4	56	93.33	46.67	56

Biologically effective dose of early responding tissue using α/β of 10. Biologically effective dose of late responding tissue using α/β of 3. Equivalent dose in 2Gy fractions (EQD2). Biologically effective dose (BED) = n x d(1 + d/α/β). n = number of treatment fractions. d = dose per fraction in Gray (Gy). = dose at which the linear and quadratic components of cell kill are equal.