[Image-guided radiotherapy for gynaecological cancer]

Abstract

Intensity-modulated radiation therapy reduces the dose to organs at risk in patients treated for gynecological malignancies. Given the steep dose gradients around the planning target volume, internal movement of organs during treatment may cause a planning target volume underdosage and organs at risk overdosage in case of systematic error. It is therefore important to take into account the movement of the pelvic organs and to investigate potential solutions provided by image-guided radiotherapy. A review of the literature was carried out using the following databases: Medline, Embase, Cochrane Library, Web of Science, Cinahl and Pubmed. Appropriate search strategies for each database were applied based upon the following terms "uterine neoplasms, image-guided radiotherapy, adaptive radiotherapy, organ motion and target volume". These studies show that uterine motion is mainly influenced by bladder filling and by cervix and vaginal vault motion due to rectal filling. Population-based clinical target volume-planning target volume margins are large resulting in unnecessary organs at risk inclusion within the planning target volume, reducing the benefits of intensity-modulated radiotherapy. As pelvic organ motion seems to be patient specific, individualised planning target volume margins and adaptive radiotherapy strategies could allow adequate coverage of the planning target volume and increase organs at risk savings. In this study, we review the different techniques of image-guided radiotherapy and the perspective of adaptive radiotherapy.

Keywords: Adaptative radiotherapy; Cancers gynécologiques; Image-guided radiotherapy; Mouvement des organes pelviens et marges; Organ motion and target volume; Radiothérapie adaptative; Radiothérapie guidée par l’image; Uterine neoplasms.