The Role of Image Guided Radiotherapy in the Treatment of Soft Tissue Sarcoma

Sarcomas are inherently exacting to treat due to the diversity of histology and anatomic locations in which sarcomas may arise. Each anatomic site poses specific challenges for ensuring accuracy of target delineation. Image guided radiotherapy (IGRT) is a technique in which pretreatment images are obtained on a regular basis to evaluate tumor and/or organs at risk (OAR) locations relative to their position on the day of CT simulation. If the tumor/OAR is misaligned, the patient is repositioned to shift the tumor/OAR into its original location. In head and neck malignancies, inconsistency in neck rotation, tumor shrinkage, and patient weight loss may contribute to interfraction variability of tumor and OAR position [1-3]. Retroperitoneal sarcomas neighbor the kidney, small bowel and other vital structures. Similarly, paraspinal soft tissue sarcomas nestle the spinal cord. Positioning accuracy is imperative. In sarcomas of the extremities, the potential for rotational motion of the extremity can besmirch the reproducibility of daily set-up. In addition, the tendency for large field size in extremity sarcomas can hinder positioning accuracy [4]. Frequent confirmation of tumor location has the potential to impact outcome and decrease morbidity. This article reviews the role of image guided radiotherapy in soft tissue sarcomas.