Motion management of lung tumors: A retrospective analysis to see dosimetric differences in different respiratory phases

• Published in: Radiation Protection and Environment Vol. 38; no. 1; p. 45
• Main Authors: Sharma, Pramod, Suchitra, Laishram, Srivastava, Roopam, Chomal, Manish, Saini, Gagan, Munshi, Anusheel, Manjhi, Jayanand, Rai, D
• Format: Journal Article
• Language: English
• Published: Mumbai Medknow Publications and Media Pvt. Ltd 01.01.2015; Medknow Publications & Media Pvt. Ltd
• Subjects: Advantages; Heart; Lung cancer; Medical imaging; Patients; Planning; Radiation therapy; Squamous cell carcinoma; Tumors
• ISSN: 0972-0464; 2250-0995
• DOI: 10.4103/0972-0464.162821

To study the effect of respiration (end expiration [EE] and end inspiration [EI]) on tumor and normal structure doses and volumes in carcinoma lung. Five patients with squamous cell carcinoma of the lung were selected for this retrospective study. Computerized tomography (CT) data set was subsequently obtained for all patients in EE and EI phases of the respiratory cycle. Gross tumor volume, clinical target volume, planning target volume (PTV) and organs at risk were delineated in both EE and EI on CT data sets. Prescribed dose was 60 Gy in 30 fractions for all patients. The PTV coverage and organs at risks (OARs) were evaluated using radiation therapy oncology group conformity indices (CI) and homogeneity indices (HI) and volume doses respectively. The CI and HI were comparable for both phases. Volumes of all OARs were comparable except the lung. OAR doses were almost same in both phases. Significantly higher normal lung volume was found in the EI phase. Based on our dosimetric data and statistical analysis we conclude that both EE and EI are dosimetrically comparable.