FDG‐PET/CT for diagnosis and follow‐up of necrotizing (malignant) external otitis

Abstract

Objective Imaging is important for the diagnosis and follow‐up of necrotizing external otitis (NEO). The best imaging modality is controversy. To suggest 2‐deoxy‐2‐[fluorine‐18] fluoro‐D‐glucose‐positron emission tomography/computed tomography (18F‐FDG‐PET/CT) as an alternative to technetium‐99m and gallium‐67 scans for diagnosis and assessment of response to treatment for patients with NEO. Study Design Case series. Methods Tertiary referral center. From 2013 through 2017, 12 patients were diagnosed with NEO based on clinical features and positive FDG uptake within the temporal bone on PET/CT. Mean age was 74 ± 11.5; 83% of the patients were male; and 83% had diabetes. Results PET/CT scans were reviewed independently by two nuclear medicine specialists. Imaging located osteomyelitis in external ear canal, mastoid, temporomandibular joint, and nasopharyngeal region (100%, 50%, 16%, 8%, respectively). Mean follow‐up was 16 months. Eight patients (67%) underwent a second PET/CT scan after active otitis resolved and after at least 6 weeks of antibiotic treatment. The scan demonstrated no or substantially reduced FDG uptake and treatment was stopped. The patients had no NEO symptoms at the end of follow‐up. One patient had significant uptake, and antibiotic treatment was continued until a third scan demonstrated no FDG uptake. Two patients died before the second PET/CT, and two were lost to follow‐up. Conclusion 18F‐FDG‐PET/CT is a reliable imaging modality for diagnosis, disease localization, and decision making regarding treatment cessation. 18F‐FDG‐PET/CT should be considered as the imaging modality of choice for initial diagnosis and follow‐up in NEO patients. Larger, controlled studies are warranted. Level of Evidence 4 Laryngoscope, 129:961–966, 2019

The challenging diagnosis and follow-up of skull base osteomyelitis in clinical practice

“…Beta-emitting tracers like FDG enable the detection of ongoing neutrophil activity in metabolically active tissue and therefore, can detect inflammation. FDG has been recommended as first choice in diagnosis and for decision-making when to stop treatment [ 9 , 30 ]. In the present study, FDG was used in PET-CT or PET-MRI in only three cases.…”

“…MRI1 corresponds to the initial MRI performed, MRI2 to the second, MRI3 to the third and so forth. The CT and MRI scans of nuclear medicine functional imaging methods are not included CT1 (30) CT2 ( 21) CT3 ( 10 patients (two PET-CT scans and one PET-MRI), which revealed increased F18-FDG tracer uptake. A scintigraphy was performed 11 times; in eight of these in combination with single-photon emission computed tomography (SPECT), whereof four were performed in combination with a CT (SPECT-CT).…”

Necrotising Otitis Externa: A Review of Imaging Modalities

“…Whilst CT and MRI are used for anatomical imaging, nuclear techniques are useful in understanding the functional process [ 13 ], depending on the availability of resources, Technetium-99 Methylene Diphosphonate (Tc-99m MDP) bone scanning, Gallium-67-citrate (Ga-67) bone scanning and Indium 111 labelled leukocyte scanning were also widely used according to some studies [ 8 ]. However, the review notes their current usage as newer and more effective imaging modalities have become available, such as 2-deoxy-2-(18F) Fluoro-D-Glucose Positron Emission Tomography/CT (18F-FDG-PET/CT) [ 29 ].…”

“…It is also worth noting that 18F-FDG-PET/CT is described as a reliable imaging modality for diagnosis, disease localization, and decision-making regarding treatment cessation of NOE [ 29 ] and considers this as the imaging modality of choice for initial diagnosis and follow-up in NOE patients. Some earlier, studies also showed that CT and/or MRI can be supplemented by single-photon emission computed tomography (SPECT) bone imaging for the initial diagnosis of NOE routinely as well as for follow-up of NOE cases.…”

What is the Best Test for Diagnosis and Monitoring Treatment Response in Malignant Otitis Externa?

“…Stern Shavit et al recently described the utility of 18 F‐FDG‐PET/CT specifically in the diagnosis and monitoring of MOE. In this case‐series of 12 patients with physical evidence of MOE, 100% of patients showed abnormal FDG uptake.…”