Image screening for maxillo-mandibular actinomycosis with CT, 18F-FDG-PET/CT, and 18F-α-methyl tyrosine PET/CT.

Clinical features and imaging findings of maxillo-mandibular actinomycosis are similar to those of intraosseous carcinoma. The purpose of this study is to clarify the characteristics of the imaging findings for screening of maxillo-mandibular actinomycosis using CT and PET.

Reports on maxillo-mandibular actinomycosis published between 1997 and 2016 were searched in PubMed using "actinomycosis," "maxilla," and "mandibular" as keywords. Ten cases suspected to have malignant tumors on diagnostic imaging findings were selected. In addition, three patients who visited Gunma University Hospital were also included. The 13 total cases were subjected to a pooled analysis of diagnostic screening of maxillo-mandibular actinomycosis using CT, ¹⁸F-FDG-PET/CT (FDG-PET/CT) and ¹⁸F-α-methyl tyrosine PET/CT (FAMT-PET/CT). Additionally, cases of intraosseous carcinoma were analyzed as comparative controls to investigate the difference between maxillo-mandibular actinomycosis and intraosseous carcinoma on CT imaging.

CT images of the 13 cases with maxillo-mandibular actinomycosis were investigated; spotty-type bone resorption was observed in 66.7% (8/12). Moreover, FDG-PET/CT showed abnormal accumulation, but FAMT-PET/CT showed no apparent abnormal accumulation.Clinical and imaging findings of maxillo-mandibular actinomycosis are similar to those of intraosseous carcinoma. Differential diagnostic screening can confirm spotty-type bone resorption in cortical bone with CT and specific accumulation in malignant tumors with FAMT-PET/CT. This screening facilitates the rapid implementation of therapeutic interventions.