Systemic Inflammation Score for Predicting Radiation-Induced Trismus and Osteoradionecrosis of the Jaw Rates in Locally Advanced Nasopharyngeal Carcinoma Patients

We sought to determine the predictive value of the systemic inflammation score (SIS) for radiation-induced trismus (RIT) and osteora-dionecrosis of the jaw (ORNJ) in locally advanced nasopharyngeal carcinoma (LA-NPC) patients treated with concurrent chemoradio-therapy (C-CRT). LA-NPC patients (n= 188) who underwent C-CRT and pre-and post-C-CRT oral examinations from August 2010 to January 2022 were included. The three-tiered SIS groups were created using the serum albumin and lymphocyte-to-monocyte ratio (LMR) measures obtained on the first day of C-CRT: SIS-0: Albumin ≥ 40 g/dL and LMR ≥ 4.44); SIS-1: Albumin < 40 g/dL and LMR < 4.44 or albumin ≥ 0 g/dL and LMR ≥ 4.44; and SIS-2: Albumin < 40 g/dL and LMR <4.44. The primary objective was to ascertain whether there were irrefutable associations between pretreatment SIS groups and the respective post-C-CRT RIT and ORNJ rates. RIT and ORNJ were diagnosed in 33 (17.6%) and 21 (11.1%) patients, respectively. There were 12 (32.4%), 13 (12.7%), and 18 (45.0%) cases diagnosed with RIT in the respective SIS-0, SIS-1, and SIS-2 groups (p< 0.001). Similarly, there were 1 (2.7%), 11 (9.9%), and 9 (22.5%) cases with ORNJ diagnoses in the corresponding SIS groups (p< 0.001). The multivariate analysis’s findings revealed that the SIS grouping was an independent predictor of RIT (p< 0.001) and ORNJ incidence rates (p< 0.001). Our study’s findings indicate that the novel pretreatment SIS grouping is a dependable biomarker-based system, which can accurately predict the rates of RIT and ORNJ in LA-NPC patients who receive definitive C-CRT.