PURPOSE: To evaluate the local positioning uncertainties during fractionated radiotherapy of head-and-neck cancer patients immobilized using a custom-made fixation device and discuss the effect of possible patient correction strategies for these uncertainties. METHODS AND MATERIALS: A total of 45 head-and-neck patients underwent regular control computed tomography scanning using an in-room computed tomography scanner. The local and global positioning variations of all patients were evaluated by applying a rigid registration algorithm. One bounding box around the complete target volume and nine local registration boxes containing relevant anatomic structures were introduced. The resulting uncertainties for a stereotactic setup and the deformations referenced to one anatomic local registration box were determined. Local deformations of the patients immobilized using our custom-made device were compared with previously published results. Several patient positioning correction strategies were simulated, and the residual local uncertainties were calculated. RESULTS: The patient anatomy in the stereotactic setup showed local systematic positioning deviations of 1-4 mm. The deformations referenced to a particular anatomic local registration box were similar to the reported deformations assessed from patients immobilized with commercially available Aquaplast masks. A global correction, including the rotational error compensation, decreased the remaining local translational errors. Depending on the chosen patient positioning strategy, the remaining local uncertainties varied considerably. CONCLUSIONS: Local deformations in head-and-neck patients occur even if an elaborate, custom-made patient fixation method is used. A rotational error correction decreased the required margins considerably. None of the considered correction strategies achieved perfect alignment. Therefore, weighting of anatomic subregions to obtain the optimal correction vector should be investigated in the future.
PURPOSE: To evaluate the local positioning uncertainties during fractionated radiotherapy of head-and-neck cancerpatients immobilized using a custom-made fixation device and discuss the effect of possible patient correction strategies for these uncertainties. METHODS AND MATERIALS: A total of 45 head-and-neck patients underwent regular control computed tomography scanning using an in-room computed tomography scanner. The local and global positioning variations of all patients were evaluated by applying a rigid registration algorithm. One bounding box around the complete target volume and nine local registration boxes containing relevant anatomic structures were introduced. The resulting uncertainties for a stereotactic setup and the deformations referenced to one anatomic local registration box were determined. Local deformations of the patients immobilized using our custom-made device were compared with previously published results. Several patient positioning correction strategies were simulated, and the residual local uncertainties were calculated. RESULTS: The patient anatomy in the stereotactic setup showed local systematic positioning deviations of 1-4 mm. The deformations referenced to a particular anatomic local registration box were similar to the reported deformations assessed from patients immobilized with commercially available Aquaplast masks. A global correction, including the rotational error compensation, decreased the remaining local translational errors. Depending on the chosen patient positioning strategy, the remaining local uncertainties varied considerably. CONCLUSIONS: Local deformations in head-and-neck patients occur even if an elaborate, custom-made patient fixation method is used. A rotational error correction decreased the required margins considerably. None of the considered correction strategies achieved perfect alignment. Therefore, weighting of anatomic subregions to obtain the optimal correction vector should be investigated in the future.
Authors: Markus Stoll; Eva Maria Stoiber; Sarah Grimm; Jürgen Debus; Rolf Bendl; Kristina Giske Journal: PLoS One Date: 2016-12-29 Impact factor: 3.240
Authors: Shane Mesko; He Wang; Samuel Tung; Congjun Wang; Dario Pasalic; Bhavana V Chapman; Amy C Moreno; Jay P Reddy; Adam S Garden; David I Rosenthal; G Brandon Gunn; Steven J Frank; Clifton D Fuller; William Morrison; Jack Phan Journal: Int J Radiat Oncol Biol Phys Date: 2019-09-30 Impact factor: 7.038
Authors: Michael Schwarz; Kristina Giske; Armin Stoll; Simeon Nill; Peter E Huber; Jürgen Debus; Rolf Bendl; Eva M Stoiber Journal: Radiat Oncol Date: 2012-08-08 Impact factor: 3.481
Authors: Matthias Felix Haefner; Frederik Lars Giesel; Matthias Mattke; Daniel Rath; Moritz Wade; Jacob Kuypers; Alan Preuss; Hans-Ulrich Kauczor; Jens-Peter Schenk; Juergen Debus; Florian Sterzing; Roland Unterhinninghofen Journal: Oncotarget Date: 2018-01-08