title: Lymphatic transit rate as a novel predictive parameter for nodal metastasis in primary truncal skin cancers.
abstract: Prediction of nodal metastasis in skin cancer before sentinel lymph node (SLN) biopsies is ideal to avoid unnecessary SLN biopsy performance. Primary truncal skin cancers are characterized by the lymphatic flow that drains from the primary lesion, occasionally to plural nodal basins. The scintigraphic appearance time (SAT), defined as the time between radionuclide injection and first SLN visualization, can potentially predict nodal metastasis, and a short SAT is a predictive parameter for metastasis. We recently introduced a novel method to measure the lymphatic flow rate using dynamic lymphoscintigraphy exhibiting a time-activity curve in the SLN. The time at which the count reaches a plateau in the SLN is termed the scintigraphic saturation time (SST) and can be a good alternative to the SAT. Moreover, the value obtained by division of the distance between the primary lesion and the SLN by the SST was termed the lymphatic transit rate (LTR), which represents the scintigraphic saturation velocity. In the present study, we evaluated LTR as a predictive parameter for nodal metastasis. Data for 22 lymph nodes from 18 patients with primary truncal skin cancers were used. Histopathologically, nodal metastasis was determined in nine nodes of eight patients. Because the mean LTR were 1.84 cm/min in non-metastatic SLN and 2.38 cm/min in metastatic SLN, the LTR was significantly higher in metastatic SLN than in non-metastatic SLN. All SLN with LTR of less than 1.8 cm/min were histopathologically evaluated as non-metastatic. The LTR may be a predictive indicator for nodal metastasis.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Fujiwara
authors.affiliation: Department of Dermatology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Plastic and Reconstructive Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takiguchi
authors.affiliation: Department of Plastic and Reconstructive Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Fukamizu
authors.affiliation: Department of Dermatology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Tokura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008196:Lymph / Q000000981:diagnostic imaging / Q000502:physiology; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D042601:Lymphatic Vessels / Q000000981:diagnostic imaging; D061305:Lymphoscintigraphy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000000981:diagnostic imaging
keywords: lymphatic flow rate; lymphoscintigraphy; metastasis; scintigraphic appearance time; skin cancer