Feasibility of using intensity-modulated radiotherapy to improve lung sparing in treatment planning for distal esophageal cancer

• Published in: Radiotherapy and oncology Vol. 77; no. 3; pp. 247 - 253
• Main Authors: Chandra, Anurag, Guerrero, Thomas M., Liu, H. Helen, Tucker, Susan L., Liao, Zhongxing, Wang, Xiaochun, Murshed, Hasan, Bonnen, Mark D., Garg, Amit K., Stevens, Craig W., Chang, Joe Y., Jeter, Melinda D., Mohan, Radhe, Cox, James D., Komaki, Ritsuko
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01-12-2005
• Subjects: Dose-Response Relationship, Radiation; Esophageal cancer; Esophageal Neoplasms - radiotherapy; Humans; Intensity-modulated radiotherapy; Radiotherapy, Intensity-Modulated - methods; Three-dimensional conformal radiotherapy; Treatment Outcome; Treatment planning; Intensity-modulated radiotherapy; Three-dimensional conformal radiotherapy; Treatment planning; Esophageal cancer
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2005.10.017

To evaluate the feasibility whether intensity-modulated radiotherapy (IMRT) can be used to reduce doses to normal lung than three-dimensional conformal radiotherapy (3DCRT) in treating distal esophageal malignancies.
Ten patient cases with cancer of the distal esophagus were selected for a retrospective treatment-planning study. IMRT plans using four, seven, and nine beams (4B, 7B, and 9B) were developed for each patient and compared with the 3DCRT plan used clinically. IMRT and 3DCRT plans were evaluated with respect to PTV coverage and dose–volumes to irradiated normal structures, with statistical comparison made between the two types of plans using the Wilcoxon matched-pair signed-rank test.
IMRT plans (4B, 7B, 9B) reduced total lung volume treated above 10
Gy (
V
10), 20
Gy (
V
20), mean lung dose (MLD), biological effective volume (
V
eff), and lung integral dose (
P<0.05). The median absolute improvement with IMRT over 3DCRT was approximately 10% for
V
10, 5% for
V
20, and 2.5
Gy for MLD. IMRT improved the PTV heterogeneity (
P<0.05), yet conformity was better with 7B–9B IMRT plans. No clinically meaningful differences were observed with respect to the irradiated volumes of spinal cord, heart, liver, or total body integral doses.
Dose–volume of exposed normal lung can be reduced with IMRT, though clinical investigations are warranted to assess IMRT treatment outcome of esophagus cancers.