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

Abstract

BACKGROUND AND PURPOSE:

To evaluate the feasibility whether intensity-modulated radiotherapy (IMRT) can be used to reduce doses to normal lung than three-dimensional conformal radiotherapy (3 DCRT) in treating distal esophageal malignancies.

PATIENTS AND METHODS:

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 3 DCRT plan used clinically. IMRT and 3 DCRT 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.

RESULTS:

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.

CONCLUSIONS:

Dose-volume of exposed normal lung can be reduced with IMRT, though clinical investigations are warranted to assess IMRT treatment outcome of esophagus cancers.

• Authors: Anurag Chandra, Thomas M Guerrero, H Helen Liu, Susan L Tucker, Zhongxing Liao, Xiaochun Wang, Hasan Murshed, Mark D Bonnen, Amit K Garg, Craig W Stevens, Joe Y Chang, Melinda D Jeter, Radhe Mohan, James D Cox, Ritsuko Komaki
• Journal: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology (Radiother Oncol) Vol. 77 Issue 3 Pg. 247-53 (Dec 2005) ISSN: 0167-8140 [Print] Ireland
• PMID: 16298001 (Publication Type: Clinical Trial, Journal Article, Research Support, N.I.H., Extramural)

Topics

• Dose-Response Relationship, Radiation
• Esophageal Neoplasms (radiotherapy)
• Humans
• Radiotherapy, Intensity-Modulated (methods)
• Treatment Outcome