6 Tumor motion for SBRT and IMRT treatment of lung cancer

Introduction The aim of this study was to determinate breathing amplitude and amplitude of lung tumor motion for Stereotactic Body Radiation Therapy (SBRT) with small (5 cm) tumor volume. Method and materials In this study we had thirty male patients. The patients were separated in two groups depending on tumor volume and treatment technique. In the first group we had 15 patients with small volume who underwent SBRT treatment. While other group of 15 patients, with large volume, were treated with IMRT technique. All patients were scanned with GE LightSpeed scanner, IMRT patients one time (2.5 mm) and SBRT patients two times (1.25 mm) with interval of one week between two scans. The contouring was performed in all ten phases for all patients, in Varian Eclipse 13.7 treatment planning system (TPS). Results Amplitude of tumor motion was 5.9 mm (range from 2 to 10.9 mm) for tumor volume 3.8 cc (range from 0.7 to 11.2 cc) for SBRT patients. The IMRT patients had amplitude of tumor motion 2.9 mm (range from 2 to 4.8 mm) for tumor volume 120.4 cc (range from 44.4 to 416.2 cc). Breathing amplitude was 14.6 mm (range from 8.5 mm to 22.6 mm) for SBRT patients and 12.1 mm (range from 7.5 mm to 18.2 mm) for IMRT patients. Conclusion The mobility and direction of tumor motion depend of the localization in the lungs. While amplitude of breathing depends of general condition of patient, physiology of lungs, respiratory problems and pain.