Margriet Kwint

Chapter 2 34 The LF and RF rates were not significantly different ( Table 4 and Fig. 1a-b ). The median PFS was not significantly different as well (supplementary material, Fig. S1b ). However, a significant difference was found between the OS of the 2 cohorts (P=0.006, HR 0.63, 95%CI 0.45-0.88; Fig 1C). The median OS was 26 months (IQR 11-56) for the reference-cohort versus 35 months (IQR 19 – N.A.) for the reduction-cohort, respectively. The 1-, 2- and 3- year OS was 70.6%, 51.8% and 38.1% for the reference- cohort and 87.6%, 66.8% and 49.4% for the reduction-cohort, respectively. Table 5 represents a Cox proportional hazards model for OS in the reduction-cohort. MLD and pulmonary toxicity influenced the association to some extent, but not entirely. No differences were found in the association between the reduction-cohort and OS for cCRT or sCRT/RT (HR 0.67; HR 0.83).