Margriet Kwint

Chapter 2 32 Characteristic Reference (N=170) Reduction (N=138) Total N=308 P-value N-stage N1 N2 N3 10.0% (17) 71.2% (121) 18.8% (32) 14.5% (20) 63.0% (87) 22.5% (31) 37 (12.0%) 67.5% (208) 20.5% (63) 0.284 TNM-stage (%) IIB IIIA IIIB IIIC IVa 5.3% (9) 38.8% (66) 47.1% (80) 8.2% (14) 0.6% (1) 3.6% (5) 40.6% (56) 41.3% (57) 11.6% (16) 2.9% (4) 4.5% (14) 39.6% (122) 44.5% (137) 9.7% (30) 1.6% (5) 0.345 Histology (%) Adenocarcinoma Squamous cell Not otherwise specified 42.4% (72) 37.6% (64) 20.0% (34) 44.2% (61) 34.8% (48) 21.0% (29) 43.2% (133) 36.4% (112) 20.5% (63) 0.873 Chemotherapy Concurrent Sequential + RT alone 68.2% (116) 31.8% (54) 72.5% (100) 27.5% (38) 70.1% (216) 29.9% (92) 0.420 Median GTV (cc) (IQR) Primary tumour Lymph nodes Tumour and nodes 51.9 (10.7-117.2) 15.9 (6.5-39.2) 83.6 (46.1-170.0) 52.2 (13.1-119.7) 16.8 (8.0-38.3) 87.0 (42.0-151.8) 51.9 (12.6-118.5) 16.3 (7.1-38.7) 85.5 (44.3-158.2) 0.891 0.475 0.501 Median PTV (cc) (IQR) Primary tumour Lymph nodes Tumour and nodes 332.5 (123.9-457.6) 192.1 (84.5-270.5) 471.7 (278.0-592.8) 252.4 (78.6-378.1) 155.1 (66.7-201.7) 393.0 (244.5-510.6) 298.8 (87.9-411.5) 175.0 (77.0-245.9) 437.9 (256.3-551.2) 0.013 0.035 0.031 GTV = gross tumour volume; PTV = planning target volumes; IQR = interquartile range; RT = radiotherapy