Skull Base Regeneration During Treatment With Chemoradiation for Nasopharyngeal Carcinoma: A Case Report.

Background: Advanced cases of nasopharyngal carcinoma can present with skull base invasion. Treatment of these advanced cases with radiotherapy poses a challenge given proximity of tumor to critical neural structures as well as concern that a skull base defect and associated complications could develop with tumor regression. Case Presentation: A 34-year-old male patient presented with a 7-cm nasopharyngeal tumor invading the skull base with destruction of the clivus and intracranial extension. He underwent a course of definitive chemoradiation, requiring use of adaptive radiotherapy, that resulted in complete tumor regression and is free of disease 5 years posttreatment. Imaging done during treatment demonstrated that significant regeneration of bone occurred simultaneously with tumor regression. Conclusions: This case demonstrates that it is possible for bony regeneration to occur simultaneously with tumor regression in a patient with skull base invasion by tumor, precluding the need for neurosurgical intervention.