Slow dynamics of lymphoscintigraphic mapping is associated to the negativity of the sentinel node in melanoma patients.
OBJECTIVE
To confirm an association between a slow kinetics in the lymphoscintigraphic mapping of the sentinel node (SN), and SN negativity (SN-) in melanoma (MM) patients, and to test whether a long scintigraphic appearance time (SAT) could be a noninvasive surrogate marker of SN-.


METHODS
A retrospective cohort of 194 successive MMs with Breslow >/=1.5 mm with follow-up >18 months after SN procedure were retrospectively randomized into two groups: a test sample (T) (two-thirds) to assess the relationship between SN status and lymphoscintigraphy dynamics, and to identify a potential scintigraphic marker of SN-, which was confirmed in the validation sample (V) (one-third). A prospective cohort of 150 consecutive new patients was then used to test the negative predictive value (NPV) of this marker.


RESULTS
In sample T, SAT was significantly lower in SN+ than SN- patients (p = 0.04). In a multivariate model, SAT was predictive of SN status, before tumor thickness. SAT was also predictive of disease of disease-free survival (DFS) and overall survival (OS). None of the patients with SAT >30 min (24.8%) were SN+. SAT >30 min was validated as a potential marker for SN- in sample V with NPV = 100% (confidence interval [CI] 84.6-100). In the prospective cohort, the NPV of this marker was however only 84.6% (CI 65.1-95.6).


CONCLUSIONS
Slow SAT is associated with SN- and better survival, which opens interesting hypotheses as to the process of the first nodal metastasis. However, the best possible lymphoscintigraphic marker was not consistent enough to recognize patients in whom the invasive phase of SN biopsy could be avoided.
Mahieu-Renard
Laurence
L
Department of Dermatology, Sainte-Marguerite Hospital, 270 boulevard de Sainte-Marguerite, 13009, Marseille, France.
Cammilleri
Serge
S
Giorgi
Roch
R
Gaudy-Marqueste
Caroline
C
Mundler
Olivier
O
Richard
Marie-Aleth
MA
Grob
Jean-Jacques
JJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D015996:Survival Rate; D013671:Technetium Tc 99m Sulfur Colloid
D019275:Radiopharmaceuticals; D013671:Technetium Tc 99m Sulfur Colloid