Superior constrictor muscle12/19/2023 Heterogeneity in PCM definition among clinicians within the study may lead to erroneous interpretation of RT-related morbidity, and consequently affect the assessment and interpretation of the primary endpoint of the study. DARS (CRUK/14/014) is a phase III randomized controlled trial in the UK that is currently investigating the functional benefits of reducing dose to the constrictors with dysphagia-optimized intensity-modulated RT (Do-IMRT), relative to standard IMRT, in cancers of the oropharynx and hypopharynx ( 3). The successful implementation of swallow-sparing RT techniques in HNC is therefore reliant on contouring accuracy of this critical swallowing organ at risk (SW-OAR) to facilitate optimal avoidance during RT planning. Sparing RT dose to this critical dysphagia/aspiration at risk structure (DARS) is paramount to improve long-term swallowing function. Irradiation of the pharyngeal constrictor muscle (PCM) is implicated with post-radiotherapy (RT) dysphagia in head and neck cancer (HNC), resulting in increased risks of aspiration, prolonged feeding tube dependency, and worsened health-related quality of life ( 1, 2). This did not impact on delivered dose to this structure with Do-IMRT, or on estimated swallowing toxicity, in this single benchmark case. Mean clinician NTCP was 24.6% (SD 0.6), compared to the GS-NTCP of 24.7%.Ĭonclusions: Results from this benchmark case demonstrate that inaccurate PCM delineation existed, even with protocol guidelines. Delineation variability did not significantly affect the mean dose delivered to the constrictors, relative to the GS plan. High IOV in SMPCM and IPCM delineation was observed by the low DICE similarity coefficient value, along with high geographical miss index and discordance index values. Results: For GS, SMPCM, and IPCM volumes were 13.51 and 1.67 cm 3 corresponding clinician mean volumes were 12.18 cm 3 (SD 3.0) and 2.40 cm 3 (SD 0.9) respectively. The influence of delineation variability on dose delivered to the constrictor muscles with Do-IMRT and resultant normal tissue complication probability (NTCP) for physician-scored radiation-associated dysphagia at 6 months was evaluated. Methods and Materials: Outlining accuracy of 15 clinicians’ superior and middle PCM (SMPCM) and inferior PCM (IPCM) were retrospectively assessed against gold standards (GS) using volume, location, and conformity indices (CIs) on a pre-trial benchmark case of oropharyngeal cancer. 5Clinical Trials and Statistics Unit, Institute of Cancer Research, London, United Kingdomīackground and Purpose: To evaluate the inter-observer variation (IOV) in pharyngeal constrictor muscle (PCM) contouring, and resultant impact on dosimetry and estimated toxicity, as part of the pre-trial radiotherapy trial quality assurance (RTQA) within DARS, a multicenter phase III randomized controlled trial investigating the functional benefits of dysphagia-optimized intensity-modulated radiotherapy (Do-IMRT) in pharyngeal cancers.4Department of Physics, Royal Marsden NHS Foundation Trust, London, United Kingdom.3Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, United Kingdom.2Division of Radiotherapy and Imaging, Institute of Cancer Research, London, United Kingdom.1Head and Neck Unit, Royal Marsden NHS Foundation Trust, London, United Kingdom. 03, respectively).Imran Petkar 1,2*†, Dualta McQuaid 3, Alex Dunlop 3, Justine Tyler 4, Emma Hall 5 and Chris Nutting 1,2 This remained significant on multivariate analysis for both penetration-aspirationĪnd activity limitation (95% CI, 2.05-58.2, P =. Worse for patients who received a biologically equivalent mean dose of > 60 Gy to the PCMs. On univariate analysis, all 3 swallowing measures were statistically significantly 02, respectively) and the mean dose to the total PCM (95% CI, 1.02-1.23 P =. Activity limitation was also associated with the mean dose to the superior, 003, respectively) and the mean dose to the total PCM (95% CI, 1.05-1.31 P =. Penetration-aspiration was associated with the mean dose to the superior, On multivariate analysis, the percentage of pharyngeal residue was statistically significantlyĪssociated with the mean dose to the superior PCM (95% confidence interval, 0.15-1.66
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |