title: CalcNTCP: a simple tool for computation of normal tissue complication probability (NTCP) associated with cancer radiotherapy.
abstract: OBJECTIVE
  This study was aimed to develop a simple and user-friendly software for fast and accurate computation of normal tissue complication probability (NTCP) in accordance with the Lyman model.
  
  
  METHODS
  The software CalcNTCP has been developed in Visual Basic and is equipped with two functional modes. Mode 1 is based on pre-stored values of various parameters for 27 different organ systems and the user has only to input the values of volume fraction (v) and radiation dose (D), whereas Mode 2 is designed for the customized entries.
  
  
  RESULTS
  The results of software validation have demonstrated that CalcNTCP is more efficient and time-saving as compared to manual or semi-manual procedures. The shapes and locations of representative survival curves generated by CalcNTCP-based computations for various radiation doses (10 - 100 Gy) and reference volumes (0.33 - 1.00) absolutely matched with optimal curves.
  
  
  CONCLUSIONS
  CalcNTCP is a simple, fast and accurate tool for the computation of NTCP with a direct implication in the evaluation or optimization of radiotherapy treatment plans.
authors.affiliation: Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia. khan_haseeb@yahoo.com
authors.forename: Haseeb Ahmad
authors.initials: HA
authors.lastname: Khan
mesh_terms: D000465:Algorithms; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008954:Models, Biological; D009369:Neoplasms / Q000532:radiotherapy*; D011336:Probability; D011832:Radiation Injuries; D020266:Radiotherapy, Conformal / Q000379:methods*; D012984:Software; D016019:Survival Analysis