title: Dose--volume effects on patient-reported acute gastrointestinal symptoms during chemoradiation therapy for rectal cancer.
abstract: OBJECTIVE
  Research on patient-reported outcomes (PROs) in rectal cancer is limited. We examined whether dose-volume parameters of the small bowel and large bowel were associated with patient-reported gastrointestinal (GI) symptoms during 5-fluorouracil (5-FU)-based chemoradiation treatment for rectal cancer.
  
  
  METHODS
  66 patients treated at the Brigham & Women's Hospital or Massachusetts General Hospital between 2006 and 2008 were included. Weekly during treatment, patients completed a questionnaire assessing severity of diarrhea, urgency, pain, cramping, mucus, and tenesmus. The association between dosimetric parameters and changes in overall GI symptoms from baseline through treatment was examined by using Spearman's correlation. Potential associations between these parameters and individual GI symptoms were also explored.
  
  
  RESULTS
  The amount of small bowel receiving at least 15 Gy (V15) was significantly associated with acute symptoms (p = 0.01), and other dosimetric parameters ranging from V5 to V45 also trended toward association. For the large bowel, correlations between dosimetric parameters and overall GI symptoms at the higher dose levels from V25 to V45 did not reach statistical significance (p = 0.1), and a significant association was seen with rectal pain from V15 to V45 (p < 0.01). Other individual symptoms did not correlate with small bowel or large bowel dosimetric parameters.
  
  
  CONCLUSIONS
  The results of this study using PROs are consistent with prior studies with physician-assessed acute toxicity, and they identify small bowel V15 as an important predictor of acute GI symptoms during 5-FU-based chemoradiation treatment. A better understanding of the relationship between radiation dosimetric parameters and PROs may allow physicians to improve radiation planning to optimize patient outcomes.
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Chen
authors.forename: Harvey J
authors.initials: HJ
authors.lastname: Mamon
authors.forename: Marek
authors.initials: M
authors.lastname: Ancukiewicz
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Killoran
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Crowley
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Blaszkowsky
authors.forename: Jennifer Y
authors.initials: JY
authors.lastname: Wo
authors.forename: David P
authors.initials: DP
authors.lastname: Ryan
authors.forename: Theodore S
authors.initials: TS
authors.lastname: Hong
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects; D000069287:Capecitabine; D059248:Chemoradiotherapy / Q000009:adverse effects* / Q000379:methods; D003672:Defecation; D003841:Deoxycytidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D003967:Diarrhea / Q000209:etiology; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives; D005767:Gastrointestinal Diseases / Q000209:etiology*; D006801:Humans; D007420:Intestine, Large / Q000528:radiation effects; D007421:Intestine, Small / Q000528:radiation effects*; D008297:Male; D008404:Massachusetts; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D011788:Quality of Life; D012004:Rectal Neoplasms / Q000628:therapy*
chemical_list: D000970:Antineoplastic Agents; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil