Radiotherapy scheduling using prime numbers

Abstract

Background: The optimal delivery of radiation therapy to achieve maximum tumour cell kill while limiting damage to normal tissues underlies any radiation therapy treatment protocol. The biological effectiveness of radiation therapy is closely related to cellular reproductive activity. The scheduling of dose fraction to a time where actively dividing cells are at their most radiosensitive stage (RS) has potential to enhance therapeutic efficacy. Materials and methods:A prime number is a natural number >1 whose only divisors are 1 and the number itself.Purpose: We propose that the use of prime numbers in the scheduling of radiotherapy treatments could maximise biological effectiveness by facilitating the irradiation of the greatest number of cells at their most RS stage, and ultimately improve the therapeutic ratio of radiation therapy. Conclusions:The theoretical clinical implementation of this concept into the scheduling of radiation therapy is discussed.