E = n(αd + βd2)
E = n(αd + βd2)
where E is the cell kill (measured in logs), n is the number of fractions, d is the dose of a single fraction of radiation (Gray units).
This occurs since cells involved in long-term damage are preferentially affected by β killing. Practically, this suggests that while different radiation regimens are equivalent in treating and controlling cutaneous carcinomas, the regimen that uses a higher doseper-fraction (while reaching the same total dose) will ultimately lead to worse longterm cosmesis.17