PURPOSE: To quantify the intrafraction motions of the larynx during radiotherapy of laryngeal cancer. Depending on the magnitude, duration, and incidence, these motions may have clinical consequences for the choice of margins around the clinical target volume. METHODS AND MATERIALS: The intrafraction motions were analyzed for 10 patients, treated in 33 or 35 fractions. The intrafraction motions of the larynx were visualized using an a-Si flat panel imager. Images were obtained every 200 ms, resulting in a movie of images for each beam. In addition to visual analysis of all movies, the tip of the epiglottis was delineated and used as a landmark, the coordinates of which were followed in time. RESULTS: Movies were obtained during 79% of the total number of radiotherapy fractions. The total duration of swallowing was on average 0.45% (range 0.0-1.5) of the total irradiation time. Deviations of motions other than swallowing ranged between 0.3 and 11.5 mm. Some of these motions were more sudden, and others were probably related to breathing, because the frequency of these motions was 8-20/min. CONCLUSION: The incidence and total duration of swallowing is low. Therefore, it is not necessary to apply an internal margin to take into account these displacements. Other motions, however, occur more often. In 95% of the irradiation time, the tip of the epiglottis moves within a range of 7.1 mm. A margin should be applied to the clinical target volume to take into account these motions.
PURPOSE: To quantify the intrafraction motions of the larynx during radiotherapy of laryngeal cancer. Depending on the magnitude, duration, and incidence, these motions may have clinical consequences for the choice of margins around the clinical target volume. METHODS AND MATERIALS: The intrafraction motions were analyzed for 10 patients, treated in 33 or 35 fractions. The intrafraction motions of the larynx were visualized using an a-Si flat panel imager. Images were obtained every 200 ms, resulting in a movie of images for each beam. In addition to visual analysis of all movies, the tip of the epiglottis was delineated and used as a landmark, the coordinates of which were followed in time. RESULTS: Movies were obtained during 79% of the total number of radiotherapy fractions. The total duration of swallowing was on average 0.45% (range 0.0-1.5) of the total irradiation time. Deviations of motions other than swallowing ranged between 0.3 and 11.5 mm. Some of these motions were more sudden, and others were probably related to breathing, because the frequency of these motions was 8-20/min. CONCLUSION: The incidence and total duration of swallowing is low. Therefore, it is not necessary to apply an internal margin to take into account these displacements. Other motions, however, occur more often. In 95% of the irradiation time, the tip of the epiglottis moves within a range of 7.1 mm. A margin should be applied to the clinical target volume to take into account these motions.
Authors: Mohamed Shelan; Lukas Anschuetz; Adrian D Schubert; Beat Bojaxhiu; Alan Dal Pra; Frank Behrensmeier; Daniel M Aebersold; Roland Giger; Olgun Elicin Journal: Strahlenther Onkol Date: 2017-05-04 Impact factor: 3.621
Authors: Mischa de Ridder; Cornelis P J Raaijmakers; Frank A Pameijer; Remco de Bree; Floris C J Reinders; Patricia A H Doornaert; Chris H J Terhaard; Marielle E P Philippens Journal: Cancers (Basel) Date: 2022-06-20 Impact factor: 6.575
Authors: J Cacicedo; J F Perez; R Ortiz de Zarate; O del Hoyo; F Casquero; A Gómez-Iturriaga; A Lasso; E Boveda; P Bilbao Journal: Clin Transl Oncol Date: 2014-07-19 Impact factor: 3.405
Authors: Hoon Sik Choi; Bae Kwon Jeong; Hojin Jeong; Jin Ho Song; Jin Pyeong Kim; Jung Je Park; Seung Hoon Woo; Ki Mun Kang Journal: Radiat Oncol J Date: 2016-03-30
Authors: Cornelia A J M Vugts; Chris H J Terhaard; Marielle E P Philippens; Frank A Pameijer; Nicolien Kasperts; Cornelis P J Raaijmakers Journal: Radiat Oncol Date: 2014-09-04 Impact factor: 3.481