Experimental and clinical studies on regional lymph drainage of the skin using sup(99m)Tc-labelled antimony trisulphide colloid

124 male and female patients aged 18 to 83 were examined pre-operatively with the newly developed and standardized lymphoscintigraphic method for establishing the regional lymph drainage pattern of a circumscribed skin tumour. Each patient received peritumoral interstitial injections of 1.5-2.0 mCi of sup(99m)Tc-Sb2S3 colloid, both intracutaneously and subcutaneously. Lymphoscintigrams were made by means of a gamma camera 3 to 6 h p.i. and the regional lymph node group(s) of the primary tumour was (were) identified. No principal difference in regional lymph drainage pattern between malignant melanomas and benign pigmented naevi was objectivized. Based on the regional lymph drainage pattern identified by lymphoscintigraphy, it was possible to purposefully perform preventive lymph adenectomy on 42 high-risk melanomas and, while doing so, to detect histologically 31% of clinically obscure lymph node metastases. The lymphoscintigraphic method, however, turned out to be inappropriate for scintigraphic verification of metastases, espec. micrometastases, already existing in the regional lymph node group established. Results showed that lymphoscintigraphy, in the form practised, constitutes an appropriate reproduceable method for non-invasive identification of the regional lymph node group(s) with malignant skin melanoma. The method is indicated in cases of primary tumour localization on the skin of the trunk, proximal upper arm, shoulder, neck/throat and head. (orig./MG)