Fig. 2

Bar charts showing an increase of the higher relative dose proportion of the RP volume from clinical appearance to maximum radiographic volume expansion after median 3.75 months (range, 2.0–7.75) after completion of radiotherapy. Statistically significant changes (red letters) for relative dose proportion less than 20 Gy and 40 Gy (left bar chart), as well as for doses less than 30 Gy towards doses above 30 (right bar chart), were observed. The dose span from 20 to 40 Gy showed an almost constant proportion of the pneumonitic lung volume of 30.6 and 28.3% at diagnosis and at maximum expansion, respectively (left bar chart)