Thompson Jf

Lymphoscintigraphy to identify sentinel lymph nodes in patients with melanoma.

Lymphoscintigraphy (LS) has been performed for 8 years in patients of the Sydney Melanoma Unit, to define lymphatic drainage patterns. Over the past 2 years, LS has also been used to locate the sentinel lymph node prior to surgery. Our technique for LS and subsequent sentinel node biopsy has an accuracy of 97%. All sentinel nodes must be marked to ensure the successful application of the sentinel biopsy technique. We have found that the axilla and groin average just over one sentinel node per draining node group for lesions on the trunk and upper limb, but have noted that drainage to the groin differed when lower limb lesions were studied. Because of the anastomosis of lymph vessels in the upper thigh, multiple sentinel nodes are identified in the groin in some patients. We have found an average of three sentinel nodes in the groin when lymph drainage from lower limb lesions was studied with LS. This difference demands a modification of the LS technique, with early imaging of the groin nodes to identify all sentinel nodes in each patient. The depth of the sentinel nodes can also be measured and the location of all interval nodes marked on the skin. This ensures that all sentinel nodes and interval nodes can be removed at the time of surgery.

Variability of cutaneous lymphatic flow rates in melanoma patients.

Preoperative lymphoscintigraphy was performed in 198 consecutive patients with cutaneous melanoma prior to their definitive surgical treatment. After intradermal injection of antimony sulphide colloid labelled with technetium- 99m, lymphatic flow rates were measured in each patient and found to vary according to the location of the primary tumour. The fastest flow rates occurred from melanoma sites on the distal limbs, particularly the lower limbs. The slowest flow rates were from the head and neck region and the proximal limbs, especially the upper arms and shoulders. Lack of flow in the early dynamic images occurred most commonly for tumours on the upper arms and shoulders. These results can be used to optimize the timing of blue dye injection prior to surgery and may influence the sentinel node biopsy method to be used in individuals who show no early drainage.

Determinants of acute regional toxicity following isolated limb perfusion for melanoma.

Hyperthermic isolated limb perfusion (ILP) with melphalan is well established as an effective form of treatment for recurrent melanoma confined to an extremity. High drug concentrations in the limb are readily achieved, without systemic side-effects. However, regional toxicity can lead to considerable morbidity and functional disturbance. This study was undertaken to evaluate factors which might contribute to acute regional toxicity following ILP. Melphalan concentrations in limb blood samples taken at regular intervals during 135 ILPs were measured by HPLC, allowing peak melphalan concentration and area under the curve (AUC) for each procedure to be determined. Acute regional toxicity associated with ILP was found to be significantly correlated with limb tissue temperatures >40ºC, peak melphalan concentration and melphalan AUC, in decreasing order, but was not correlated with tourniquet time. Further studies are required to directly assess melphalan uptake by tumour tissue, and to relate this to both limb toxicity and tumour response.