REF008 - Bone Infection Imaging (Gallium Scan)

The purpose of this document is to assist clinicians in deciding on the appropriateness of the nuclear medicine procedure and to give guidance on the mechanism of referral.

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 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 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.

Referring clinicians are reminded of the requirement to avoid unnecessary exposure to ionising radiation. The investigation may already have been requested at this hospital or elsewhere and clinicians are asked to be particularly vigilant to ensure that their request is not a double request.

Requests will only be accepted if the diagnostic question fulfills one of the referral criteria below. Appropriate clinical information must be supplied to allow the investigation to be justified. It is not acceptable to simply request the investigation without appropriate clinical information.

Requests will be returned to the referrer if:

• The diagnostic question is unclear.
• The diagnostic question cannot be answered by the investigation.
• Insufficient clinical information is supplied to justify the investigation.

Requests should be submitted on the orange stripe NUCLEAR MEDICINE (ISOTOPE SCAN) request form. Patient details, Investigation required and Reason for Test/Diagnostic Question should be fully and appropriately completed and the form signed.

Note the requirement for patient preparation below

Sufficient clinical information must be provided to justify the investigation proceeding.

• Avoid Gadolinium enhanced MRI imaging in the 24 hours prior to the administration of Ga67^[1]