The promising treatment schedule of concurrent chemoradiotherapy for stage III non-small cell lung cancer: Alternative for conventional fractionation using mathematical analysis

Abstract

Background/Aim: To evaluate treatment schedules involving concurrent chemoradiotherapy in stage III non-small cell lung cancer (NSCLC) using the tumor control probability (TCP) and normal tissue complication probability (NTCP) parameters. Patients and Methods: The standard schedules were compared with two types of schedules, the dose escalation and the short-term schedules. Standard schedules were 60-74 Gy in 30-37 fractions. The dose escalation schedules with hypofractionation and hyperfractionation were 69 Gy in 30 fractions and 69.6 Gy in 58 fractions, respectively, twice per day (b.i.d). The shortterm schedules were concomitant boost, 64 Gy in 40 fractions b.i.d. and the accelerated radiotherapy schedule, 57.6 Gy in 36 fractions, three fractions per day (t.i.d). Results: The average TCP for the short-term schedules was more than 16% in two tumor models; however, the TCP for standard and dose escalation schedules was less than 5%. In each organ, the increase in NTCP for the short-term schedule compared with standard schedules was less than 15%. Conclusion: The short-term schedules had an advantage over standard schedules for NSCLC.