Table 4.

Side effects after re-irradiation and the correlation to the overlapping volume. Abbreviations: V100 – the volume at re-irradiation with a cumulative dose of ≥100 Gy (EQD2). Toxicity was graded according to Radiation Oncology Group (RTOG) and the European Organization for Research and Treatment of Cancer (EORTC) Radiation Morbidity Schema

Side effects after re-irradiationa	Acute				Late
	V100 < mean		V100 > mean		V100 < mean		V100 > mean
	n	%	n	%	n	%	n	%
Grade 0–2	24	89	13	57	13	59	5	33
Grade ≥ 3	3	11	10	43	9	41	10	67

p-value = 0.023

p-value = 0.229

^a at least one grade 0–2, or grade ≥ 3 respectively