Clinical Experience with Proton Therapy for Gastrointestinal Cancers: A Review

Conventional radiotherapy (ie x-ray therapy) plays an important role in the multidisciplinary treatment of most of the cancers arising from the gastrointestinal (GI) tract. In this context, a narrow therapeutic window exists, due to 1) the usually large treatment volumes which are required to cover regions at risk for tumor spread and to 2) the close vicinity of several radiosensitive healthy tissues to the irradiated volume. The use of charged particles such as protons, with their unique dosimetric characteristics (a finite range in tissue along with a near zero dose beyond the end of its path), could be promising. The aim of this critical review was 1) to describe the rationale of the use of PT for the major GI cancers and 2) to report the clinical experiences currently available in literature