title: The association of rectal equivalent dose in 2 Gy fractions (EQD2) to late rectal toxicity in locally advanced cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University.
abstract: OBJECTIVE
  To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University.
  
  
  METHODS
  Retrospective study was designed for the patients with locally advanced cervical cancer, treated by radical radiotherapy from 2004 to 2009 and were evaluated by rectosigmoidoscopy. The cumulative doses of WPRT and ICBT to the maximally rectal point were calculated to the EQD2 and evaluated the association of toxicities.
  
  
  RESULTS
  Thirty-nine patients were evaluated for late rectal toxicity. The mean cumulative dose in term of EQD2 to rectum was 64.2 Gy. Grade 1 toxicities were the most common findings. According to endoscopic exam, the most common toxicities were congested mucosa (36 patients) and telangiectasia (32 patients). In evaluation between rectal dose in EQD2 and toxicities, no association of cumulative rectal dose to rectal toxicity, except the association of cumulative rectal dose in EQD2 >65 Gy to late effects of normal tissue (LENT-SOMA) scale ≥ grade 2 (p = 0.022; odds ratio, 5.312; 95% confidence interval, 1.269-22.244).
  
  
  CONCLUSIONS
  The cumulative rectal dose in EQD2 >65 Gy have association with ≥ grade 2 LENT-SOMA scale.
authors: Division of Therapeutic Radiology and Oncology, Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Ekkasit
authors: E
authors: Tharavichtikul
authors: Lampang Cancer Hospital, Lampang, Thailand.
authors: Pooriwat
authors: P
authors: Meungwong
authors: Department of Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Taned
authors: T
authors: Chitapanarux
authors: Division of Therapeutic Radiology and Oncology, Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Somvilai
authors: S
authors: Chakrabandhu
authors: Division of Therapeutic Radiology and Oncology, Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Pitchayaponne
authors: P
authors: Klunklin
authors: Division of Therapeutic Radiology and Oncology, Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Wimrak
authors: W
authors: Onchan
authors: Division of Therapeutic Radiology and Oncology, Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Somsak
authors: S
authors: Wanwilairat
authors: Biostatistics and Applied Statistics Laboratory, Department of Statistics, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.
authors: Patrinee
authors: P
authors: Traisathit
authors: Faculty of Medicine, Christian-Albrechts University at Kiel, Kiel, Germany.
authors: Razvan
authors: R
authors: Galalae
authors: Division of Therapeutic Radiology and Oncology, Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors: Imjai
authors: I
authors: Chitapanarux
keywords: Association; Cervical cancer; Cumulative dose; Radiotherapy; Rectum; Toxicity