Investigation of approaches for internal target volume definition using 4-dimensional computed tomography in stereotactic body radiotherapy of lung cancer

The present study was undertaken to investigate the suitability of alternative internal target volume (ITV) delineation strategies based on maximum intensity projection (MIP), average intensity projection (AIP), 2 extreme phases and 4 phases images relative to the ITV10phase in stereotactic body radiation therapy (SBRT) for lung cancer. The 4-dimensional computed tomography (4DCT) data of 15 lung cancer patients treated with SBRT in our clinic were used. Five different ITVs were generated as follows: merging GTVs from 10 phases (ITV10Phase); merging GTVs from 2 extreme phases (0%, 50%) (ITV2Phase); merging GTVs from 4 phases (0%, 20%, 50%, and 70%) (ITV4Phase); delineating GTV on MIP (ITVMIP), and delineating GTV on AIP (ITVAIP).
Source: Medical Dosimetry - Category: Radiology Authors: Source Type: research