Incidence of and Risk Factors for Mastoiditis after Intensity Modulated Radiotherapy in Nasopharyngeal Carcinoma.

Abstract

PURPOSE:

To report the incidence of and risk factors for mastoiditis after intensity-modulated radiotherapy (IMRT) in nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS:

Retrospective analysis of pretreatment and follow-up magnetic resonance imaging (MRI) data for 451 patients with NPC treated with IMRT at a single institution. The diagnosis of mastoiditis was based on MRI; otomastoid opacification was rated as Grade 0 (none), 1 (mild), 2 (moderate) or 3 (severe) by radiologists blinded to clinical outcome. This study mainly focused on severe mastoiditis; patients were divided into three groups: the G0M (Grade 0 mastoiditis before treatment) group, G1-2M (Grade 1 to 2 mastoiditis before treatment) group and G3M (Grade 3 mastoiditis before treatment) group. The software SAS9.3 program was used to analyze the data.

RESULTS:

For the entire cohort, the incidence of Grade 3 mastoiditis was 20% before treatment and 31%, 19% and 17% at 3, 12 and 24 months after radiotherapy, respectively. In the G0M group, the incidence of severe mastoiditis was 0% before treatment and 23%, 15% and 13% at 3, 12 and 24 months after radiotherapy, respectively. Multivariate analysis revealed T category (OR=0.68, 95% CI = 0.469 to 0.984), time (OR=0.668, 95% CI = 0.59 to 0.757) and chemotherapy (OR=0.598, 95% CI = 0.343 to 0.934) were independent factors associated with severe mastoiditis in the G0M group after treatment.

CONCLUSIONS:

Mastoiditis, as diagnosed by MRI, occurs as a progressive process that regresses and resolves over time in patients with NPC treated using IMRT.

• Authors: Ji-Jin Yao, Guan-Qun Zhou, Xiao-Li Yu, Ling-Long Tang, Lei Chen, Yan-Ping Mao, Li Lin, Lu-Lu Zhang, Jian-Yong Shao, Ying Guo, Jun Ma, Ying Sun
• Journal: PloS one (PLoS One) Vol. 10 Issue 6 Pg. e0131284 ( 2015) ISSN: 1932-6203 [Electronic] United States
• PMID: 26114761 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Aged
• Carcinoma
• Female
• Humans
• Incidence
• Male
• Mastoiditis (epidemiology, etiology)
• Middle Aged
• Nasopharyngeal Carcinoma
• Nasopharyngeal Neoplasms (epidemiology, radiotherapy)
• Radiation Injuries (epidemiology)
• Radiotherapy, Intensity-Modulated (adverse effects)
• Risk Factors