OBJECTIVETo investigate the value of the additional skull lateral static imaging in whole-body bone imaging (WBI) vs CT for evaluation of skull base invasion in patients with nasopharyngeal carcinoma.

METHODSA total of 405 patients with pathologically confirmed NPC underwent WBI with additional static imaging of the left and right skull as well as CT examination of the nasopharynx and skull base within one week before the radiotherapy.

RESULTSThe concordance rates between WBI and CT for positive and negative diagnosis were 29.48% and 76.05% in these cases, respectively, with the total concordance rate of 81.23%. The concordance rates between skull lateral static imaging with visual judgment and CT examination for positive and negative diagnosis were 67.95% and 74.07%, respectively, showing a total concordance rate of 87.16%. Skull lateral static imaging with semi-quantitative analysis and CT examination showed concordance rates for positive and negative diagnosis of 75.64% and 74.07%, respectively, with a total rate of 88.64%. In 27 patients with negative diagnosis by CT but a positive one in skull lateral static imaging with semi-quantitative analysis, 9 had a positive diagnosis by magnetic resonance imaging.

CONCLUSIONSSkull lateral static imaging can be of value in the diagnosis of skull base invasion in NPC patients and may serve as an effective means for screening skull base invasion in NPC.