title: The different dose-volume effects of normal tissue complication probability using LASSO for acute small-bowel toxicity during radiotherapy in gynecological patients with or without prior abdominal surgery.
abstract: OBJECTIVE
  To develop normal tissue complication probability (NTCP) model with least absolute shrinkage and selection operator (LASSO) to analyze dose-volume effects that influence the incidence of acute diarrhea among gynecological patients with/without prior abdominal surgery.
  
  
  METHODS
  Ninety-five patients receiving gynecologic radiotherapy (RT) were enrolled. The endpoint was defined as the grade 2(+) acute diarrhea toxicity during treatment. We obtained the range of small-bowel volume in V4 Gy to V40 Gy of dose.
  
  
  RESULTS
  The number of patients experiencing grade 2(+) acute diarrhea toxicity was 23/61 (38%) in the group without abdominal surgery (group 0) and 17/34 (50%) patients with abdominal surgery (group 1). The most significant predictor was found for the logistic NTCP model with V16 Gy as the cutoff dose for group 0 and V40 Gy for group 1. Logistic regression NTCP model parameters were TV10 ≈ 290 cc for V16 Gy and TV10 ≈ 75 cc for V40 Gy, respectively.
  
  
  CONCLUSIONS
  To keep the incidence of grade 2(+) acute small-bowel toxicity below 10%, we suggest that small-bowel volume above the prescription dose (V16 Gy) should be held to <290 cc for patients without abdominal surgery, and the prescription dose (V40 Gy) should be maintained <75 cc for patients with abdominal surgery.
authors.affiliation: Medical Physics and Informatics Laboratory of Electronics Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan.
authors.forename: Tsair-Fwu
authors.identifier: 0000-0002-3112-3594
authors.initials: TF
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, 123 Ta-Pei Road, Niao-Sung District, Kaohsiung 83305, Taiwan ; School of Traditional Chinese Medicine, Chang Gung University College of Medicine, Taoyuan 333, Taiwan.
authors.forename: Eng-Yen
authors.identifier: 0000-0002-2041-0782
authors.initials: EY
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D003967:Diarrhea / Q000453:epidemiology / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D005260:Female; D005831:Genital Diseases, Female / Q000453:epidemiology / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D007421:Intestine, Small / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D008954:Models, Biological; D011183:Postoperative Complications / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D011832:Radiation Injuries / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D011879:Radiotherapy Dosage; D013514:Surgical Procedures, Operative / Q000009:adverse effects*