Low hemoglobin levels predict increased radiation‐induced trismus rates in nasopharyngeal cancer

Abstract

AbstractPurposeTo investigate the predictive significance of hemoglobin (Hb) values in the incidence of radiation‐induced trismus (RIT) in locally advanced nasopharyngeal carcinoma (LA‐NPC) patients who received concurrent chemoradiotherapy (C‐CRT).MethodsData of LA‐NPC patients were examined before and after C‐CRT and to confirm the presence of RIT, maximum mouth openings (MMO) were measured; RIT is defined as an MMO of ≤35 mm. All Hb values were derived from complete blood count tests obtained on the first day of C‐CRT. The receiver operating characteristic (ROC) curve analysis was used to scrutinize a possible connection between pre‐treatment Hb values and RIT status.ResultsTwo hundred and twenty three patients were included in the study and RIT was diagnosed in 46 (20.6%) patients. The Hb cutoff in ROC curve analysis that separated the patients into two groups was 12.05 g/dL [Area under the curve (AUC): 82.7%; sensitivity: 72.9%; and specificity: 71.3%]. RIT was significantly more prevalent in the Hb ≤ 12 g/dL group than in its counterpart (41.9% vs. 7.3%; p < 0.001). In multivariate analysis, Hb ≤ 12, anemia, pre‐C‐CRT MMO < 41.4 mm, and masticatory apparatus doseV58 Gy < 32% groups were found to be independently associated with significantly increased rates of RIT.ConclusionLow pre‐C‐CRT Hb and anemia status are novel biological markers that independently predict higher RIT rates in LA‐NPC undergoing C‐CRT.