Search

Objectives: To investigate the relationship between nutritional supplementation and radiation dose to the pharyngeal constrictor muscles and larynx for head and neck (HN) cancer patients undergoing radiotherapy. Methods: We retrospectively analyzed radiotherapy (RT) dose for 231 HN cancer patients, focusing on the pharyngeal constrictors and larynx. We defined nutritional supplementation as feeding tube utilization or >10% weight loss from baseline within 90 days after radiotherapy completion. Using deformable image registration (DIR), we mapped each patient's anatomical structures to a reference coordinate system, and corresponding deformations were applied to dose matrices. Voxel doses were utilized as features for ridge logistic regression models, optimized through 5-fold cross-validation. Model performance was assessed with area under the curve of a receiver operating curve (AUC) and F1 score. We built and compared models using 1) pharyngeal constrictor voxels, 2) larynx voxels, 3) clinical factors and mean regional dose metrics, and 4) clinical factors and dose-volume histogram metrics. Test set AUCs were compared among the models, and feature importance was evaluated. Results: DIR of the pharyngeal constrictors and larynx yielded mean Dice coefficients of 0.80 and 0.84, respectively. Pharyngeal constrictors voxels and larynx voxel models had AUC of 0.88 and 0.82, respectively. Voxel-based dose modeling identified the superior to middle regions of the pharyngeal constrictors and the superior region of larynx as most predictive of feeding tube use/weight loss. Univariate analysis found treatment setting, treatment laterality, chemotherapy, baseline dysphagia, weight, and socioeconomic status predictive of outcome. An aggregated model using mean doses of pharyngeal constrictors and larynx subregions had an AUC of 0.87 and the model using conventional DVH metrics had an AUC of 0.85 with p-value of 0.04. Feature importance calculations from the regional dose model indicated that mean doses to the superior-middle pharyngeal constrictormuscles followed by mean dose to the superior larynx were most predictive of nutritional supplementation. Conclusions: Machine learning modeling of voxel-level doses enables identification of subregions within organs that correlate with toxicity. For HN radiotherapy, doses to the superior-middle pharyngeal constrictors are most predictive of feeding tube use/weight loss followed by the doses to superior portion of the larynx. [ABSTRACT FROM AUTHOR]

Objective To determine both the rate of delayed cervical lymph node metastasis in patients with esthesioneuroblastoma (ENB) and a clinically N0 untreated neck and the effectiveness of salvage treatment. Design Retrospective review. Setting Tertiary academic medical center. Participants All patients from January 1, 1965, to December 31, 2010, who received definitive treatment for ENB. Main Outcome Measures The study involved 52 patients: 27 (52%) patients underwent surgery and adjuvant radiotherapy (SART) to the primary site only and 25 (48%) underwent surgery alone (SA) as treatment of the primary site, without elective neck dissection. Results Median follow-up for the SART group was 10 years versus 15.7 years for the SA group. The 10-year delayed cervical lymph node metastasis estimate is 41%. With median follow-up of 47 months after salvage treatment, the 4-year cervical lymph node recurrence-free survival estimate is 70%; the 5-year overall survival estimate is 39%. Conclusions Delayed cervical lymph node metastases are common, indolent, and salvaged effectively in most patients. We propose that patients with ENB and clinically N0 cervical lymph nodes may choose to forego elective neck dissection or elective neck radiotherapy in favor of neck observation within their initial treatment. [ABSTRACT FROM AUTHOR]