Nuclear Medicine

Nuclear Medic​​ine has been around since the beginning of the 1900s and is a branch of medicine that uses radioactivity for diagnosis or therapy.

Unlike x-rays, CT and MRI scans that give structural information, Nuclear Medicine imaging demonstrates the function of an organ or organ system by monitoring the passage, accumulation or excretion of a radiopharmaceutical (a radioactive pharmaceutical).

To perform a Nuclear Medicine scan, the radiopharmaceutical is first administered to the patient, usually intravenously. Depen​​ding on the type of scan, the pictures may be taken immediately and/or after a period of time during which the pharmaceutical localises in the target organ or system.

Many injuries or disease processes tend to effect the function of an organ before the structure is altered. Nuclear Medicine plays an essential role in helping with the early diagnosis of a wide variety of diseases and conditions, which in turn can make treatment more timely and effective.

Specialist services provided by the Christchurch Hospital Nuclear Medicine Department include; Diagnostic Imaging, Radiopharmacy and Radionuclide Therapies.

How are the Images taken?

The patient is asked to lie still on an imaging bed. The gamma camera or SPECT/CT camera is positioned above and below the area/s of interest. The camera detects the signals​ (gamma rays) from the radiation that is emitted from the patient’s body. Images are obtained of the distribution within the body over a period of time. The scan may take between 10 and 120 minutes, depending on the type of study. The patient is required to lie still for the duration of the scan.

  • ​A Static image is one picture​ taken over a set time period.
  • Dynamic images are lots​ of continuous pictures which can be played back like a movie and used to measure t​​he clearance of a radiopharmaceutical from the organ of interest. The camera remains set in one position for these scans.
  • For whole body scans, the imaging bed moves the patient past the detectors, imaging from head to toe.
  • For tomography (SPECT) the detectors move round the patient to form a 3D image. Sometimes SPECT i​s followed by a low dose CT scan (SPECT/CT); the two sets of images are then fused to enhance anatomical localisation.

The mai​n advantages of SPECT/CT are represented by:

  • Bett​er attenuation correction ie. correcting for patient size and contour.
  • Increased speci​ficity
  • Accurate localisation of abnormal uptake/disease and possible involvement of adjacent str​uctures eg. bone scans.
  • Aiding the ​planning of minimally invasive surgery as it assists in pre-surgical localisation eg. parathyroid imaging.

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​​​Hospital Referrals

 Private Specialist Referrals

  • Nuclear Medicine Requisition form QF00287. 

  • Post or fax (03 3640 869) the form to the Nuclear Medicine Department.

GP Referrals

  • Nuclear Medicine Request Form – available on the CDHB HealthPathways website http://cdhb.healthpathways.org.nz/referral/Nuclear-Medicine-Request-Form.pdf. Post or fax the request to the Nuclear Medicine Department or send via GP Referrals.

  • ERMS referral. Healthpathways – Investigations – Nuclear Medicine –            Request. Select: Bone Isotope ScanRadionuclide Thyroid Scanor Nuclear Medicine Referral for other scan types. 

  • For clinical criteria, refer to Bone Pain Pathway or Thyroid Pathway.

  • ACC funded Bone Scans must be referred by a Specialist. ​

Referral Guidelines

Clerical

  • Full name of patient ie. legal name including all middle names with correct spelling

  • Date of birth and NHI number

  • Mailing address including postcode

  • Contact telephone numbers (include cell for txt reminder).

  • Name of Referrer and Practice

  • Service Requested

  • ACC number if applicable, include date and details of accident

Clinical

  • Provisional diagnosis and /or presenting problem

  • Severity and duration

  • Current medications/ known allergies

  • Relevant patient history

WEIGHT

  • Any disabilities, mobility or cognitive problems, special needs eg. interpreter, hoist etc.

  • ​​​

Availability of Imaging Procedures

  • For URGENT scans during working hours (0800 – 1630), phone the Scanning room (03 3640 867, ext. 80867) after faxing or sending an electronic referral. Urgent requests are performed as soon as possible.

  • All efforts are made to scan patients within the requested time frames indicated on the referrals.

  • Routine appointments are generally booked and sent out within a week.

  • Some types of scans are grouped together and others are only available on certain days.

  • Some specialised scans are not routinely available, contact Nuclear Medicine for advice before ordering.  

pet.jpgPositron Emission Tomography (PET) is used to demonstrate the metabolic activity of organs and other tissues such as tumours. A radioactive compound called 18FDG (fluorodeoxyglucose) is injected into the patient and the radioactive emissions are measured by a PET/CT scanner. PET is considered particularly effective in identifying whether certain types of cancers are present, if they have spread and if the patient is responding to treatment.

At this time, the Christchurch Hospital Nuclear Medicine Department does not have a PET facility. All patient referrals through the public hospital system are sent to Christchurch Radiology Group’s PET/CT scanning facility, located at:

Southern Cross Radiology

129 Bealey Ave

Christchurch

www.christchurchradiology.co.nz/pet-scans  

PET/CT scan reports and images are available on the CRG & CDHB PACS; reports are also available on éclair & CIS.

What are Radiopharmaceuticals?

The Radiopharmacy is an integral part of the Nuclear Medicine Department that deals largely with the preparation, dispensing and quality control of radio-pharmaceuticals.

Most of the doses used in diagnostic imaging Generator.JPGuse the radioactive element Technetium-99m which is obtained from a small Molybdenum-99 Generator, delivered to the department at the start of each week. Technetium is often mixed with a non-radioactive compound in order to localise the radiopharmaceutical in a specific area in the body.

Other types of radioactive compounds may be used for specialised scans or therapies. They must be used within a set period of time, which is dependant on the radioactive half-life or decay time (the time it takes for a radioactive substance to loose half its radioactivity).

Each type of Nuclear Medicine procedure will have a prescribed radiopharmaceutical and radioactive dose, measured in MBq. The amount of radioactivity is kept as low as possible and is individually calculated for children based on weight. Injection.jpgThe dose is usually administered by IV injection into a vein in the arm (pictured) but can also be given subcutanously (Sentinal Lymph Node), orally (Gastric Emptying)  or breathed in as a gas (Lung Ventilation Scan).     

The short 6-hour half-life of Technetium means that the radiopharmaceutical will clear rapidly from the body. Some radiopharmacuticals may also be cleared through the urine or excreted in breast milk.

For some scans, adults are advised to avoid close, continuous, contact with children for the rest of the day (refer to appointment letter). 

It is important for us to know if you are Pregnant or Breastfeeding.    

What about Safety?

In Nuclear Medicine every precaution is taken. 

 Exposure to radiation is:

Low: 
 
Only small quantities are used for diagnosis.
Short: 
 
The radioactive compounds used in diagnostic tests are quickly eliminated from the body.
Carefully Controlled:

Imaging services are IANZ Accredited which means that high standards for quality and safety are set and maintained.
The department is also accredited with theANZSNM.
The Office of Radiation Safety is a Specialist Unit within the  NZ Ministry of Health  responsible for regulating the use of ionising radiation.

Radioiodine (Iodine-131) Therapy

radionuclide.gifIndications

  • Thyrotoxicosis (Thyroid overactivity)

  • Multinodular goitre

  • Thyroid cancer

Healthinfo.org.nz Radioiodine for Thyroid Cancer

Healthinfo.org.nz Radioiodine Treatment for Thyrotoxicosis

How the Radioiodine works

Radioiodine works by destroying a large number of thyroid cells. The treatment is given in a drink of water or as a capsule – like an antibiotic capsule, the radioiodine has no taste. Occasionally more than one treatment is required.

How safe is Radioiodine?

Radioiodine is a very safe and effective treatment that has been used since the 1940’s. Patients will be radioactive for a short period following therapy and will need to observe some simple measures to reduce radiation exposure to other people during this time. Most patients develop hypothyroidism (thyroid underactivity) following treatment. Close follow-up with blood tests is necessary to detect this so that replacement thyroid hormone (thyroxine) can be started early.

Referral process

Patients are referred to the Thyroid Endocrine Physicians for treatment. The Physicians will discuss the indications and outcome fully and give radiation protection instructions. For Canterbury patients, follow-up will be arranged at the Thyroid Clinic.

Strontium-89 Therapy

Indications

  • Metastatic prostatic carcinoma

How the Strontium-89 works

Strontium-89 behaves like calcium in the body, when injected it will collect in the bone metastases (secondaries). These are areas of bone which are absorbing extra calcium and are often painful. It will then deliver radiation directly to the affected area, giving relief from pain.

How safe is Strontium-89?

The effects of Strontium-89 within the body are limited to the small area where it concentrates. It cannot cause any harm to any other people by bodily contact. However during the first few days after injection, some strontium-89 will be present in the blood and urine so the patient will be instructed to observe rigorous hygiene during this time.

Referral process

Patients are referred by an Oncologist licensed to give this therapy. They will discuss the indications and outcome fully and give radiation protection instructions. Nuclear Medicine Department staff will arrange the Strontium-89 delivery, dispense the dose and organise the patient appointment.

Phosphorus-32 Therapy

Indications  

  • Polycythaemia vera

  • Essential thrombocythaemia

How the Phosphorus-32 works

Following intravenous injection, the radionuclide Phosphorus-32 selectively concentrates in the rapidly dividing cells of the bone marrow and in cortical bone. The radiation delivered suppresses the growth of these cells which are dividing more rapidly than normal.

How safe is Phosphorus-32?

The effects of Phosphorus-32 within the body are limited to the areas where it concentrates. It cannot cause any harm to any other people by bodily contact. However during the first few days after injection, some phosphorus-32 will be present in the blood and urine so the patient will be instructed to observe rigorous hygiene during this time.

Referral process

Patients are referred by a Haematologist licensed to give this therapy. They will discuss the indications and outcome fully and give radiation protection instructions. Nuclear Medicine Department staff will arrange the Phosphorus-32 delivery, dispense the dose and organise the patient appointment.

Service Hours:​

8am – 5pm, Monday to Friday (closed Public Holidays)

Physical Address:

Nuclear Medicine Department
2nd Floor, Riverside Block
Christchurch Hospital

Postal Address:

Nuclear Medicine Department
Christchurch Hospital
Private Bag 4710
Christchurch 8140

Phone:

03 364 0890 (Reception)
03 364 0867 (Scanning Room)

Fax:

03 364 0869

Page last updated: 28 November 2018

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