Abstract
<h3>Purpose/Objective(s)</h3> Judicious reduction in elective nodal volumes for patients with oropharyngeal squamous cell carcinoma (OPSCC) has the potential to reduce acute and long term toxicity while maintaining high rates of regional control. We postulated that the contralateral N0 neck region at highest risk for containing occult microscopic lymph node (LN) metastases in patients with OPSCC could be best defined by the location of the initial positive ipsilateral LN. We sought to identify and target this N0 elective neck region and assess impact on dose to organs at risk compared to using a consensus-defined contralateral elective nodal volume. <h3>Materials/Methods</h3> We performed a retrospective review to identify patients with OPSCC and N2c disease as defined by a single radiographically positive LN. LN centroids were used to define the anatomic boundaries of the novel contralateral elective clinical target volume (ceCTV). Factors associated with LN centroid locations were assessed by the Fisher exact test. We used an external testing cohort to evaluate the robustness of ceCTV. The dosimetric impact of ceCTV compared to consensus elective nodal clinical target volumes (conCTV) was assessed with the t-test. <h3>Results</h3> We identified 25 patients that fit the selection criteria of which 84% had a single contralateral LN in level II and 16% in level III. We did not identify factors associated with LN centroid location. In the external data set, 97% (33/34) of the LN centroids were located within the novel elective contralateral target volume. Mean radiation dose to the contralateral parotid gland was 15.1 Gy (range 13.0-17.0 Gy) versus 21.0 Gy (range 18.0-24.0 Gy), <i>P</i> < 0.001 using the novel versus consensus elective contralateral nodal clinical target volumes, respectively. <h3>Conclusion</h3> We present a systematic approach for considering the contralateral nodal regions at highest risk of harboring subclinical disease in patients with oropharyngeal squamous cell carcinoma. These data support clinical study to evaluate this novel contralateral elective clinical target volume in patients with oropharyngeal squamous cell carcinoma who warrant elective contralateral neck radiotherapy.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: International Journal of Radiation Oncology*Biology*Physics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.