Sentinel Node Biopsy
Ultrasound is the alternative to Sentinel Node Biopsy
Four reasons to choose ultrasound surveillance over sentinel node biopsy
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Ultrasound is a simple investigation which, in experienced hands, takes minutes to perform and can be repeated as often as necessary. Sentinel node biopsy is a minor operation requiring a short hospital stay with a 10% risk of complications.
- About 20% of patients will have melanoma in the sentinel node at the time of diagnosis. The amount of tumour in the sentinel node will vary from tiny clumps of cells to complete replacement of one or more sentinel node(s). In about 25-50% of patients, the melanoma deposits can be identified by ultrasound making sentinel node biopsy unnecessary. Therefore, all patients should first have an ultrasound examination of the lymph nodes.
- Evidence is accumulating that some tiny deposits of melanoma in the sentinel node are “false-positive” meaning that they are not destined to progress and harm the patient. Instead, they are destined either for dormancy or destruction. This is a new concept in melanoma for which there is good evidence.
- Patients whose sentinel node is “false-positive” may be wrongly up-staged following sentinel node biopsy and may be advised to have unnecessary lymphadenectomy. This cannot happen in patients having ultrasound surveillance because false-positive deposits of melanoma will not grow to a size (3-4 mm) when they can be identified by ultrasound.
