Lymphatic diameters and radionuclide clearance in a murine melanoma model
S. D. Nathanson, M. Avery, P. Anaya, T. Sarantou and F. W. Hetzel
Department of Surgery, Case Western Reserve University, Henry Ford Health System, Detroit, Mich., USA.
OBJECTIVES: To determine the clearance of a radionuclide from various sizes
of footpad melanomas via lymphatics and to measure the diameters of these
vessels. DESIGN: Nonrandomized animal study. SETTING: A hospital research
laboratory. SUBJECTS: C57BL/6 mice. INTERVENTIONS: Female mice were
injected in the right rear footpad with B16 F10 cells that were allowed to
grow to either 1, 2, 3, 4, or 5 mm in anteroposterior diameter. Clearance
from feet with or without tumors of injected technetium Tc 99m human serum
albumin (99mTcHSA) was assessed for 200 minutes. Calf lymphatic diameters
were measured using aniline blue dye. RESULTS: The clearance of the
injected 99mTcHSA from mouse footpads without tumors was 1.26 +/- 0.18 x
10(-4) mL/min x cm3 of tissue. Clearance increased 2.24-fold to 2.82 +/-
0.12 x 10(-4) mL/min x cm3 of tissue from 1-mm tumors and to 6.20 +/- 0.08,
6.11 +/- 0.13, 6.91 +/- 0.58, and 7.23 +/- 0.48 x 10(-4) mL/min x cm3 of
tissue from 2-, 3-, 4-, and 5-mm tumors, respectively (P < .05). Calf
lymphatic diameters increased from 75.41 +/- 9.72 microns in naive
nontumor-bearing mice to 93.51 +/- 7.12, 111.61 +/- 27.07, 126.69 +/-
25.20, 124.43 +/- 24.75, and 127.44 +/- 25.35 microns in mice bearing 1-,
2-, 3-, 4-, and 5-mm tumors, respectively (P < .01). CONCLUSIONS: There
was a size-dependent, direct correlation between increasing tumor size in
the footpad and increasing diameter of lymphatics draining the footpad.
Clearance of injected 99mTcHSA from these tumors also exhibited a similar
positive correlation with tumor size.