Advances in Radiation Therapy for Gastrointestinal Cancers

Abstract

Radiation therapy has been a mainstay in the treatment of gastrointestinal malignancies for decades, whether utilized as the definitive local therapy, adjuvant treatment following surgery, or, more recently, in the neoadjuvant setting to improve surgical outcomes and survival. Traditional radiation therapy has evolved to allow for both more conformal delivery of radiation (e.g., intensity-modulated radiation therapy) and higher radiation dose to the target (e.g., stereotactic body radiation therapy). Consequently, higher rates of local control are coupled with reduced dose to normal structures, leading to a reduction in both acute and chronic side effects. While the proximity of key normal tissues in the abdomen, particularly the bowel, has provided a challenge to a meaningful dose delivery, these recent advances have allowed radiation to serve as the main local therapy modality in non-operable tumors. Further, by coupling these advanced radiation techniques with modern surgery and targeted chemotherapy agents, key oncologic survival outcomes have been realized. This chapter will cover advancements in radiation therapy as pertaining to multiple gastrointestinal malignancies, including a discussion of forthcoming research in the field.