[Diagnosis of sentinel lymph node in malignant melanoma: preoperative lymphoscintigraphy and intraoperative gamma probe guidance].
OBJECTIVE
The sentinel lymph node (SLN) has shown to reflect the histologic features of the remainder of the lymphatic basin in patients with melanoma and is of considerable prognostic relevance. Aim of the study was to localize the SLN pre and intraoperatively by means of lymphoscintigraphy and gamma probe guidance.


METHODS
38 patients with histologically proven malignant melanoma (tumor thickness > 0.75 mm) were preoperatively examined by injecting 40 MBq 99mTc-Nanocoll intradermally around the lesion. The first lymph node identified was marked on the skin. Immediately after scintigraphy patients were referred to the operation room and intraoperatively mapped using a handheld gamma probe. Activity of the SLN and of the adjacent nodes was measured ex vivo. After excision of the SLN, the lymphatic basin was re-checked for radioactivity and activity of the SLN and of the adjacent nodes was re-measured after removal.


RESULTS
The hottest reading was found in all patients in vivo and ex vivo in the preoperatively marked lymph node. Morphologically (macroscopically, ultrasound, CT) all nodes were unsuspicious. Histologically, in 8 patients metastatic involvement of the lymph node was found which led to a wide exploration of the lymphatic basin with consecutive lymph node excision in 7 patients.


CONCLUSIONS
The findings suggest that combined preoperative lymphoscintigraphy and intraoperative mapping with a gamma probe is a powerful approach for exact localization of the SLN. Diagnostic detection of the SLN may have considerable impact for patient management, since extended lymph node dissection may be confined to patients presenting with positive SLN.
Dresel
S
S
Klinik und Poliklinik für Nuklearmedizin, Ludwig-Maximilians-Universität München, Deutschland.
Weiss
M
M
Heckmann
M
M
Rossmüller
B
B
Konz
B
B
Tatsch
K
K
Hahn
K
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D015902:Gamma Cameras; D006801:Humans; D007271:Injections, Intradermal; D008197:Lymph Node Excision / Q000379:methods*; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D011859:Radiography; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D013668:Technetium Tc 99m Aggregated Albumin / Q000008:administration & dosage
D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid