Lower and central tumor location correlates with lymphoscintigraphy drainage to the internal mammary lymph nodes in breast carcinoma.
BACKGROUND
Radiation to the internal mammary chain (IMC) may be indicated for breast carcinoma patients with positive axillary sentinel lymph nodes (SLNs) and lymphoscintigraphic evidence of drainage to the IMC. The purpose of this study was to identify predictors of IMC drainage in patients with positive axillary SLNs.


METHODS
The records of 297 breast carcinoma patients with positive axillary SLNs and preoperative lymphoscintigraphy were reviewed between 1995 and 2002. Radiolabeled colloid was injected peritumorally with lymphoscintigraphy performed 30-60 minutes later. Drainage to the regional nodes of 279 patients was seen on lymphoscintigraphy. Associations among patient and tumor-related factors and drainage to the IMC were examined.


RESULTS
Drainage to the IMC on lymphoscintigraphy was seen in 63 patients (21%). IMC drainage only occurred in 4 patients, and 59 patients had both axillary and IMC drainage. The only variable that correlated with IMC drainage was tumor location (P = 0.017). Rates of drainage to the IMC were 14.1% for upper outer quadrant (n = 128), 16.7% for upper inner quadrant (n = 30), 31.6% for lower outer quadrant (n = 19), 42.9% for lower inner quadrant (n = 14), and 28.4% for central tumors (n = 88). IMC drainage rates differed significantly between upper and lower tumors (lower 36.4% vs. central 28.4% vs. upper 14.6%, P = 0.003) but not between medial and lateral tumors (medial 25.0% vs. central 28.4% vs. lateral 16.3%, P = 0.077).


CONCLUSIONS
Patients with tumors in the lower or central breast and positive axillary SLNs have increased incidence of drainage to the IMC. Preoperative lymphoscintigraphy can help to define the nodal basins at risk for harboring disease.
Shahar
Karen H
KH
Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
Buchholz
Thomas A
TA
Delpassand
Ebrahim
E
Sahin
Aysegul A
AA
Ross
Merrick I
MI
Ames
Fredrick C
FC
Kuerer
Henry M
HM
Feig
Barry W
BW
Meric-Bernstam
Funda
F
Babiera
Gildy V
GV
Singletary
S Eva
SE
Akins
Jeri S
JS
Mirza
Nadeem Q
NQ
Hunt
Kelly K
KK
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008875:Middle Aged; D011877:Radionuclide Imaging / Q000379:methods*; D013671:Technetium Tc 99m Sulfur Colloid
D013671:Technetium Tc 99m Sulfur Colloid