PURPOSE: The aim of this study was to estimate normal tissue complication probability (NTCP) parameters for late rectal complications after carbon ion radiotherapy (C-ion RT) for prostate cancer. METHODS AND MATERIALS: A total of 163 patients were used to derive NTCP parameters. These patients were treated with relative biological effectiveness (RBE)-weighted dose ranging from 57.6 Gy (RBE) up to 72 Gy (RBE) and included in dose escalation trials. The Lyman-Kutcher-Burman (LKB) model was used and the model parameters were fit to the relation between dose and complication observed after C-ion RT. RESULTS: The resulting NTCP parameters were the volume effect parameter; n=0.035 (95% CI: 0.024-0.047), the steepness of the NTCP curve; m=0.10 (0.084-0.13), the tolerance dose associated with 50% probability of complication; TD50=63.6 Gy (RBE) (61.8-65.4 Gy (RBE)) for Grade⩾1, n=0.012 (0.0050-0.023), m=0.046 (0.033-0.062), TD50=69.1 Gy (RBE) (67.6-70.9 Gy (RBE)) for Grade⩾2. CONCLUSION: A new set of rectal NTCP parameters in C-ion RT was determined. The rather small n values suggest that the rectum was consistent with being strictly serial organ. The new derived parameter values facilitate estimation of rectal NTCP in C-ion RT.
PURPOSE: The aim of this study was to estimate normal tissue complication probability (NTCP) parameters for late rectal complications after carbon ion radiotherapy (C-ion RT) for prostate cancer. METHODS AND MATERIALS: A total of 163 patients were used to derive NTCP parameters. These patients were treated with relative biological effectiveness (RBE)-weighted dose ranging from 57.6 Gy (RBE) up to 72 Gy (RBE) and included in dose escalation trials. The Lyman-Kutcher-Burman (LKB) model was used and the model parameters were fit to the relation between dose and complication observed after C-ion RT. RESULTS: The resulting NTCP parameters were the volume effect parameter; n=0.035 (95% CI: 0.024-0.047), the steepness of the NTCP curve; m=0.10 (0.084-0.13), the tolerance dose associated with 50% probability of complication; TD50=63.6 Gy (RBE) (61.8-65.4 Gy (RBE)) for Grade⩾1, n=0.012 (0.0050-0.023), m=0.046 (0.033-0.062), TD50=69.1 Gy (RBE) (67.6-70.9 Gy (RBE)) for Grade⩾2. CONCLUSION: A new set of rectal NTCP parameters in C-ion RT was determined. The rather small n values suggest that the rectum was consistent with being strictly serial organ. The new derived parameter values facilitate estimation of rectal NTCP in C-ion RT.
Authors: K E Applegate; W Rühm; A Wojcik; M Bourguignon; A Brenner; K Hamasaki; T Imai; M Imaizumi; T Imaoka; S Kakinuma; T Kamada; N Nishimura; N Okonogi; K Ozasa; C E Rübe; A Sadakane; R Sakata; Y Shimada; K Yoshida; S Bouffler Journal: Radiat Environ Biophys Date: 2020-03-07 Impact factor: 1.925
Authors: Paulo Magalhaes Martins; Hugo Freitas; Thomas Tessonnier; Benjamin Ackermann; Stephan Brons; Joao Seco Journal: Sci Rep Date: 2021-07-28 Impact factor: 4.379