title: Nausea and vomiting induced by gastrointestinal radiation therapy: current status and future directions.
abstract: OBJECTIVE
  Radiation therapy-induced nausea and vomiting (RINV) are common and troublesome symptoms among patients receiving radiation therapy for gastrointestinal cancers. Their impact on function, quality of life and, ultimately, cancer control warrant a review of their incidence, underlying mechanisms, treatments and research themes.
  
  
  RESULTS
  Research in RINV is underrepresented relative to that in chemotherapy-induced nausea and vomiting. The incidence of RINV among patients receiving modern day radiation therapy is questioned and supportive care practice patterns vary among radiation oncologists. Antiemetic guideline recommendations for prophylactic and rescue therapy are based solely on the anatomic region being irradiated and not other patient-related, radiation therapy-related, or organ-specific dosimetric factors that likely modulate the risk of RINV. Dosimetric predictors are likely the most attainable biomarker moving forward, but only early steps have been taken. The small bowel and stomach will be the best first candidates for study among patients with gastrointestinal cancers. Studies of the mechanisms underlying RINV are conspicuously lacking. A new generation of observational studies and therapeutic clinical trials is needed, and more attention must be given to the relative impact of nausea and vomiting on the function and quality of life among specific homogeneous patient populations.
  
  
  CONCLUSIONS
  Optimal supportive care strategies for RINV following radiation therapy for gastrointestinal cancers are lacking, and will not be known until future research answers the many open questions regarding the mechanisms underlying RINV, the true incidence and impact of these symptoms among patients and the best way to predict and mitigate them.
authors: aDivision of Radiation Oncology, University of Ottawa bOttawa Hospital Research Institute, Ottawa cFaculty of Medicine dDepartment of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
authors: Kristopher
authors: K
authors: Dennis
authors: Michael
authors: M
authors: Poon
authors: Edward
authors: E
authors: Chow
mesh_terms: D000932:Antiemetics / Q000627:therapeutic use; D005770:Gastrointestinal Neoplasms / Q000150:complications / Q000532:radiotherapy*; D006801:Humans; D009325:Nausea / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control*; D017410:Practice Guidelines as Topic; D011878:Radiotherapy / Q000009:adverse effects; D014839:Vomiting / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000932:Antiemetics