Table 4 Inter-rate agreement between patient, physician and outside observer (O.O.) evaluations of cosmetic results at time of starting and ending of radiotherapy and after 1, 3, 6, 9, and 12 months; Cohen’s kappa with confidence interval and p value of the two-sided hypothesis test

Start

0.37 (− 0.03–0.70)

P = 0.019

0.23 (− 0.12–0.61)

P = 0.113

0.41 (0.05–0.77)

P = 0.016

End

0.45 (0.03–0.78)

P = 0.008

0.20 (− 0.09–0.59)

P = 0.133

0.57 (0.22–0.92)

P = 0.002

1 month

0.42 (0.09–0.78)

P = 0.018

0.63 (0.25–0.91)

P < 0.001

0.59 (0.25–0.93)

P = 0.002

3 month

0.42 (0.07–0.79)

P = 0.018

0.63 (0.29–0.91)

P < 0.001

0.56 (0.19–0.93)

P = 0.003

6 month

0.15 (−0.18–0.60)

P = 0.204

0.54 (0.22–0.89)

P < 0.001

0.52 (0.13–0.91)

P = 0.005

9 month

0.24 (− 0.06–0.60)

P = 0.086

0.64 (0.34–0.91)

P < 0.001

0.53 (0.16–0.90)

P = 0.002

12 month

0.10 (−0.21–0.41)

P = 0.266

0.40 (0.08–0.72)

P = 0.013

0.14 (− 0.35–0.63)

P = 0.266

24 month

0.28 (0.00–0.77)

P = 0.051

0.60 (0.00–1.00)

P < 0.001

0.56 (0.04–1.00)

P = 0.001