REF008 - Malignant Otitis Externa Imaging (Gallium Scan) Referral Criteria

See REF000 - Referring to Nuclear Medicine (NLAG) for details on how to refer.

A standard three phase bone scan is usually the first nuclear medicine investigation in suspected bone infection. This bone scan is typically abnormal within 48 hours of the onset of symptoms in contrast to the 10 to 12 days taken for radiographic changes to become apparent. In some cases, the bone infection diagnosis may still be in doubt and further investigation may be necessary.

Labelled white cell studies are indicated in a wide variety of suspected infective or inflammatory orthopaedic conditions. These studies are not available within North Lincolnshire and Goole NHS Trust but can be performed at Hull University Teaching Hospitals NHS Trust.

For the investigation of malignant otitis externa, a Gallium (Ga-67) scan may be performed at North Lincolnshire and Goole NHS Trust.

Ga-67 citrate is a bone seeking radiopharmaceutical showing increased uptake at sites of increased metabolic activity. Focally increased accumulation of radiopharmaceutical greater than that seen on the corresponding three phase bone scan, or in areas that do not correspond precisely to discrete lesions on the bone scan are strongly suggestive of infection.

• The referrer may be any UK registered medical practitioner currently employed in Secondary Care.
• Referrals from Primary Care will be accepted if the investigation has been suggested by a Secondary Care Specialist or a Consultant Radiologist in a report from a previous investigation; or following discussion with a Consultant Radiologist. Details of such suggestions or discussions should be included on the request form.

• Sodium chloride for parenteral use (0.9% w/v)

• Note that this study is often combined with a standard three phase bone scan immediately before the administration of the Ga-67.
• For follow-up studies, a bone scan is not usually required - but the ARSAC licence holder may specifically request it if required.
• Avoid Gadolinium enhanced MRI imaging in the 24 hours prior to the administration of Ga67^[1]