Clinical Acceptability of Automated Radiation Treatment Planning for Head and Neck Cancer Using the Radiation Planning Assistant.

PURPOSE: Radiation treatment planning for head and neck cancer is a complex process with much variability; automated treatment planning is a promising option to improve plan quality and efficiency. This study compared radiation plans generated from a fully automated radiation treatment planning system to plans generated manually that had been clinically approved and delivered. METHODS AND MATERIALS: The study cohort consisted of 50 patients treated by a specialized head and neck cancer team at a tertiary care center. An automated radiation treatment planning system, the Radiation Planning Assistant, was used to create autoplans for all patients using their original, approved contours. Common dose-volume histogram (DVH) criteria were used to compare the quality of autoplans to the clinical plans. Fourteen radiation oncologists, each from a different institution, then reviewed and compared the autoplans and clinical plans in a blinded fashion. RESULTS: Autoplans and clinical plans were very similar with regard to DVH metrics for coverage and critical structure constraints. Physician reviewers found both the clinical plans and autoplans acceptable for use; overall, 78% of the clinical plans and 88% of the autoplans were found to be usable as is (without any edits). When asked to choose which plan would be preferred for approval, 27% of physician reviewers selected the clinical plan, 47% selected the autoplan, 25% said both were equivalent, and 0% said neither. Hence, overall, 72% of physician reviewers believed the autoplan or either the clinical or autoplan was preferable. CONCLUSIONS: Automated radiation treatment planning creates consistent, clinically acceptable treatment plans that meet DVH criteria and are found to be appropriate on physician review.

Does Thyroid Gland Preserving Total Laryngectomy Affect Oncological Control in Laryngeal Carcinoma?

INTRODUCTION: Thyroid lobectomy is recommended with total laryngectomy in the National Comprehensive Cancer Network guidelines. However, it is associated with a 32% to 89% risk of hypothyroidism, which is a problem for patients without access to thyroid hormone monitoring and replacement. A number of studies have reported a low incidence of thyroid gland involvement and recommended preserving the thyroid gland in favorable cases. Yet there are no studies that report whether thyroid preserving laryngectomy for laryngeal cancer adversely affects oncologic outcomes compared to patients who have undergone thyroid lobectomy. OBJECTIVES: To determine whether patients who underwent thyroid gland preserving laryngectomy had higher local recurrence rates or poorer disease-free survival. METHOD: A retrospective folder review of patients who underwent a total laryngectomy over a 12-year period was conducted. Local recurrence and disease-free survival were determined for patients who had both their thyroid lobes preserved and compared with those who had a thyroid lobectomy. RESULTS: Sixty-nine patients had thyroid preserving laryngectomy and 73 patients had a thyroid lobectomy. The duration of follow-up was 18 to 132 months (median, 30; IQR, 30). There was no significant difference in local recurrence rates (P = .76) or survival curves between the two groups. CONCLUSION: Thyroid preserving laryngectomy in selected patients with advanced laryngeal carcinoma does not increase local recurrence rates, nor does it negatively affect disease-free survival. Thyroid preservation is appropriate when intraoperative inspection of the larynx shows no extralaryngeal extension or when paratracheal nodal metastases are not a concern. LEVEL OF EVIDENCE: Level 4 Laryngoscope, 130:1465-1469, 2020.

Retrospective Validation and Clinical Implementation of Automated Contouring of Organs at Risk in the Head and Neck: A Step Toward Automated Radiation Treatment Planning for Low- and Middle-Income Countries.

Purpose We assessed automated contouring of normal structures for patients with head-and-neck cancer (HNC) using a multiatlas deformable-image-registration algorithm to better provide a fully automated radiation treatment planning solution for low- and middle-income countries, provide quantitative analysis, and determine acceptability worldwide. Methods Autocontours of eight normal structures (brain, brainstem, cochleae, eyes, lungs, mandible, parotid glands, and spinal cord) from 128 patients with HNC were retrospectively scored by a dedicated HNC radiation oncologist. Contours from a 10-patient subset were evaluated by five additional radiation oncologists from international partner institutions, and interphysician variability was assessed. Quantitative agreement of autocontours with independently physician-drawn structures was assessed using the Dice similarity coefficient and mean surface and Hausdorff distances. Automated contouring was then implemented clinically and has been used for 166 patients, and contours were quantitatively compared with the physician-edited autocontours using the same metrics. Results Retrospectively, 87% of normal structure contours were rated as acceptable for use in dose-volume-histogram-based planning without edit. Upon clinical implementation, 50% of contours were not edited for use in treatment planning. The mean (± standard deviation) Dice similarity coefficient of autocontours compared with physician-edited autocontours for parotid glands (0.92 ± 0.10), brainstem (0.95 ± 0.09), and spinal cord (0.92 ± 0.12) indicate that only minor edits were performed. The average mean surface and Hausdorff distances for all structures were less than 0.15 mm and 1.8 mm, respectively. Conclusion Automated contouring of normal structures generates reliable contours that require only minimal editing, as judged by retrospective ratings from multiple international centers and clinical integration. Autocontours are acceptable for treatment planning with no or, at most, minor edits, suggesting that automated contouring is feasible for clinical use and in the ongoing development of automated radiation treatment planning algorithms.

Genetic variation in Otos is associated with cisplatin-induced ototoxicity.

BACKGROUND: Ototoxicity is an adverse drug reaction that may limit the effective use of cisplatin chemotherapy. Given the reported in vitro protective role of the gene Otos in response to cisplatin, this study aimed to explore the potential of Otos as a genetic modifier of ototoxicity. PATIENTS & METHODS: One hundred South African cisplatin-receiving cancer patients with baseline and follow-up audiometric data were screened for variation in exonic target regions of Otos using direct cycle sequencing. RESULTS: A total of 29 genetic variants were identified. The G alleles of Otos rs77124181 (c.-192-182C>G) and rs2291767 (c.-192-22A>G) were over-represented in ototoxicity-free patients (p = 0.022). Cumulative cisplatin dose and anatomical site of cancer were also associated with ototoxicity, while self-reported ethnicity associated with the ototoxic severity. CONCLUSION: This study indicates a potentially protective role for the variant G alleles of SNPs rs77124181 and rs2291767 in Otos against the development of cisplatin-induced ototoxicity.