Dose-volumetric parameters of acute esophageal toxicity in patients with lung cancer treated with three-dimensional conformal radiotherapy.
OBJECTIVE
To retrospectively evaluate which dose-volumetric parameters are associated with the risk of > or = Grade 3 acute esophageal toxicity (AET) in lung cancer patients treated with three-dimensional conformal radiotherapy (3D-CRT).


METHODS
One hundred twenty-four lung cancer patients treated curatively with 3D-CRT were retrospectively analyzed. All patients received conventionally fractionated radiotherapy (RT) with median dose of 60 Gy (range, 54-66 Gy) delivered in 30 fractions (range, 27-33 fractions). Thirty-one patients underwent curative surgery before RT. Ninety-two patients received chemotherapy (induction, 18; concurrent +/- induction, 74). Acute esophageal toxicity was scored by Radiation Therapy Oncology Group criteria. The parameters analyzed included sex; age; Karnofsky performance score; weight loss; surgery; concurrent chemotherapy; the percentages of organ volume receiving > or =20 Gy (V20), > or =30 Gy (V30), > or =40 Gy (V40), > or =50 Gy (V50), > or =55 Gy (V55), > or = 58 Gy (V58), > or =60 Gy (V60), and > or =63 Gy (V63); the percent and absolute length of the esophagus irradiated; the maximum and mean dose to the esophagus; and normal tissue complication probability.


RESULTS
Of the 124 patients, 15 patients (12.1%) had Grade 3 AET, and 1 (0.8%) patient had Grade 4 AET. There was no fatal Grade 5 AET. In univariate and multivariate logistic regression analyses, concurrent chemotherapy and V60 were significantly associated with the development of severe (> or = Grade 3) AET (p < 0.05). Severe AET was observed in 15 of 74 patients (20.3%) who received concurrent chemotherapy, and in 1 of 50 patients (2.0%) who did not (p = 0.002). Severe AET was observed in 5 of 87 patients (5.7%) with V60 < or = 30% and in 11 of 37 patients (29.7%) with V60 > 30% (p < 0.001). Among 50 patients who did not receive concurrent chemotherapy, severe AET was observed in 0 of 43 patients (0%) with V60 < or = 30% and in 1 of 7 patients (14.2%) with V60 > 30% (p = 0.140). Among 74 patients who received concurrent chemotherapy, severe AET was observed in 5 of 44 patients (11.4%) with V60 < or = 30% and in 10 of 30 patients (33.3%) with V60 > 30% (p = 0.037).


CONCLUSIONS
Concurrent chemotherapy and V60 were associated with the development of severe AET > or = Grade 3. For patients being treated with concurrent chemotherapy, V60 is considered to be a useful parameter predicting the risk of severe AET after conventionally fractionated 3D-CRT for lung cancer.
Kim
Tae Hyun
TH
Research Institute and Hospital, National Cancer Center, Madu 1-dong, Ilsan-gu, Goyang, Gyeonggi 411-769, South Korea.
Cho
Kwan Ho
KH
Pyo
Hong Ryull
HR
Lee
Jin Soo
JS
Han
Ji Youn
JY
Zo
Jae Ill
JI
Lee
Jong Mog
JM
Hong
Eun Kyoung
EK
Choi
Il Ju
IJ
Park
Sung Yong
SY
Shin
Kyung Hwan
KH
Kim
Dae Yong
DY
Kim
Joo Young
JY
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects; D003131:Combined Modality Therapy; D004941:Esophagitis / Q000209:etiology; D004947:Esophagus / Q000528:radiation effects*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D012044:Regression Analysis; D012189:Retrospective Studies