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IMAGING IN MELANOMA – local guidelines. Dr Andrea J Howes Consultant Radiologist St Helens and Knowsley NHS Trust. Local Imaging Guidelines – how to image?. Options include CXR, ultrasound, CT, MR, and PET CT, as well as sentinel node mapping and biopsy
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IMAGING IN MELANOMA –local guidelines Dr Andrea J Howes Consultant Radiologist St Helens and Knowsley NHS Trust
Local Imaging Guidelines – how to image? • Options include CXR, ultrasound, CT, MR, and PET CT, as well as sentinel node mapping and biopsy • There are advantages and disadvantages for each
Local Imaging Guidelines – how to image? • Imaging should be performed after histological examination of primary and clinical assessment • This avoids unnecessary imaging of stage 1 patients • Within any clinical stage, specific symptoms or signs suggestive of metastases should be imaged accordingly
Stage 1 • There is no evidence for any benefit of imaging in stage 1 disease
Stage 2 • SLNB is performed locally for further staging • This is expensive and time consuming so CXR and US should be performed prior to this (although no evidence for imaging in stage 2A) • CT results in large numbers of false positives with resulting anxiety, re-scan and high radiation burden
Stage 3 • Positive SLNB or clinical adenopathy • CT of chest / abdomen for nodes in neck or axilla and abdomen / pelvis for groin nodes • Yield low if nodes not palpable (0.5 – 3.7%) • Yield higher if palpable nodes (4 – 16%) • MR of neck nodes may be helpful • False positives are still a significant problem
Stage 4 • CT of chest, abdomen and pelvis • Further investigations as clinically indicated • No evidence for imaging the brain unless symptomatic
PET CT • Indications for PET CT are very specific nationally • Locally, the only melanoma indication is where metastectomy is being considered eg: in a patient with a pulmonary nodule, to establish whether it is a metastasis and to look for evidence of other disease not seen at CT
REFERENCE “Role of Imaging Investigations in the Staging of Primary Cutaneous Melanoma – Recommended Guidelines for MCCN with Summary of Available Evidence.” Dr J C Herbert October 2009
SENTINEL LYMPH NODE BIOPSY IN MELANOMA – THE WHISTON EXPERIENCE Dr Andrea J Howes Consultant Radiologist St Helens and Knowsley NHS Trust
CONSULTANT RADIOLOGIST EXPERIENCE • Whiston was one of the first centres in the country to perform SLNB • Dr J Herbert started SLN imaging in November 1999 • Dr A Howesstarted SLN imaging in 2004 • From commencing in November 1999 to end of April 2010 we had performed 564 procedures
NUCLEAR MEDICINE DEPARTMENT REQUIREMENTS • Large amount of legislation! • The Radiologist has to have a licence issued by the Health Minister (ARSAC licence) to use radioactive isotopes – there are specific training requirements • The licence is site specific • Another doctor may work under a colleagues certificate if it is only a short-term temporary absence, provided you are working under the certificate holder's written directions. • The licence holder is responsible for the operating surgeons involvement with the isotope
NUCLEAR MEDICINE DEPARTMENT REQUIREMENTS • The department also has to be appropriately licensed (including the HSE) and needs access to a radiopharmacy (with appropriate transport licensing if required) • Single or dual headed gamma camera • SPECT CT capability may be of benefit • Appropriately trained radiographers / nuclear medicine technicians
WHAT DOES IT INVOLVE? • Time consuming! • Technitium 99m (Tc99m) labelled colloid • Injected intradermally around primary excision site • Dynamic images obtained allow visualisation of channels and can be useful to resolve problems such as kinks in channels (20 minutes, 60 images each – AP and lateral)
WHAT DOES IT INVOLVE? • Static images are obtained – usually AP and lateral (5 minutes each) • These images are used for marking with a Cobalt-57 tipped “pen” • Static oblique images (further 5 minutes) obtained to confirm position and depth • Position checked with gamma probe
Melanoma site SN 2nd
SN Melanoma site SN SN
SN Melanoma site SN
SPECT CT • A new dual headed camera with SPECT CT (Single Photon Emission Computed Tomography CT) was installed in 2005 • SPECT CT provides SPECT images, low dose CT for anatomical localisation and fused images • This adds considerably to the time taken and the radiation dose, but has apparently proven invaluable in terms of surgery
OUR USE OF SPECT CT • Initially for localisation in head and neck melanomas to give additional information • Localisation where node is obscured by injection site in one plane • Localisation where 2 nodes are apparently close together • Position in large patients (eg: above or below inguinal ligament) • Localisation where position seems abnormal (eg: nodes found close to scapula rather than in axilla)
PROGRESS • Increasing numbers mean a Consultant may not always be immediately available in the department • Consequently 3 radionuclide radiographers (M. Caffrey, J. Winfield, J. Kerr) have trained to mark straightforward nodes • Consultant always involved for head and neck and other nodes needing SPECT CT as well as any others which seem technically difficult