Three-dimensional surface imaging for detection of intra-fraction setup variations during radiotherapy of pelvic tumors

• Published in: Radiologia medica 2016-10, Vol.121 (10), p.805-810
• Main Authors: Apicella, Giuseppina, Loi, Gianfranco, Torrente, Sara, Crespi, Silvia, Beldì, Debora, Brambilla, Marco, Krengli, Marco
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Diagnostic Radiology; Female; Genital Neoplasms, Female - radiotherapy; Genital Neoplasms, Male - radiotherapy; Humans; Image acquisition; Imaging; Interventional Radiology; Ionizing radiation; Male; Medicine; Medicine & Public Health; Middle Aged; Misalignment; Monitoring; Neuroradiology; Patient Positioning; Patients; Quality Assurance, Health Care; Radiation therapy; Radiology; Radiotherapy; Radiotherapy Setup Errors - prevention & control; Radiotherapy, Image-Guided - methods; Reproducibility; Reproducibility of Results; Three dimensional bodies; Tumors; Ultrasound
• ISSN: 0033-8362; 1826-6983
• DOI: 10.1007/s11547-016-0659-9

Purpose Surface-based image guided radiotherapy (IGRT) allows positioning and/or monitoring patients in 3 dimensions (3D), without the use of ionizing radiation. In this study, we report on intra-fraction motion measured by acquisition of multiple images of 3D body surfaces. Materials and methods Twenty-nine patients treated for pelvic tumors were enrolled. Setup variations (SV) through three consecutive body surfaces acquired by the optical IGRT system Align-RT (Vision-RT, London, UK) were analyzed before, during and at the end of treatment delivery. Displacements along the main axes ( X , Y and Z ) from initial (I) to mid-treatment (MT) and final (F) acquisitions were recorded. Time and direction of SV were assessed. Results A total of 6272 images from 792 fractions of 29 patients were available. The main source of misalignment was between I and MT acquisition ( p