(A1114) Early Detection of Osteoradionecrosis in Nasopharyngeal Carcinoma: The Role of Computed Tomography in Routine Surveillance

Introduction: Osteoradionecrosis (ORN) is a late complication of radiotherapy for nasopharyngeal carcinoma (NPC) often diagnosed an average of 3.8 years post-treatment. Routine imaging surveillance may miss early osseous changes, thus delaying diagnosis. We hypothesize that CT scans, which are more sensitive for detecting bone abnormalities, could reduce time to diagnosis (TTD).

Methods: We conducted a retrospective chart review of patients diagnosed with ORN following radiotherapy for NPC. We collected patient demographics, symptoms, treatment history, and imaging. TTD was compared between patients whose ORN was first detected by CT versus routine imaging (MRI or PET). Statistical analysis assessed imaging performance and clinical factors influencing diagnostic timelines.

Results: Eighteen patients (72.2%, mean age = 58.03) were included in this study. The mean time from radiotherapy completion to ORN diagnosis was 5.5 years. ORN was first detected by CT in 50% of patients, with a shorter TTD compared to routine imaging (425.11 vs 32.00 days, p = 0.01) and fewer days between images (22.11 vs 232.20 days, p = 0.019). Patients with CT scans after initial imaging had a shorter TTD than those who only underwent routine surveillance, though this was not significant (135.82 days vs 375.29 days, p = 0.221). CT detected ORN earlier than MRI (p = 0.036) though not earlier than PET (p = 0.498). TTD was unaffected by the presence of symptoms or lesion location (p = 0.14, p = 0.13). Most patients (61.1%) underwent surgical debridement while 33.3% underwent hyperbaric therapy or observation.

Conclusions: CT imaging may reduce diagnostic delays for ORN compared to routine MRI or PET. Its adjunctive use in routine surveillance may facilitate timely intervention and mitigate the severity of ORN, thus improving patient outcomes.