Will There Be a Clinically Significant Role for Protons in Patients With Gastrointestinal Malignancies?

Gastrointestinal malignancies inherently arise amidst visceral organs that are very radiation sensitive. While radiation therapy is an integral part of cancer treatment, its use has historically been limited by normal tissue toxicity. Proton therapy is a form of external-beam radiation associated with several dosimetric advantages as compared to photon therapy. Proton radiation may allow for the delivery of tumoricidal doses while minimizing side effects by decreasing the dose to adjacent organs at risk. We discuss the rationale for and challenges of using protons in the treatment of gastrointestinal cancers. We describe the available data and ongoing trials using proton radiation to treat these tumors. Finally, we discuss the unique challenges of using protons to treat gastrointestinal malignancies.