Efficacy and safety of (32)P-nanocolloid for treatment of distant lymph node metastasis in VX2 tumor-bearing rabbits.
BACKGROUND
Eradication of micrometastases present in lymph nodes of cancer patients improves their prognosis significantly. Radionuclide therapy possesses the potential to eliminate such metastases.


OBJECTIVE
This study was performed to evaluate the efficacy and safety of (32)P-nanocolloid therapy in the treatment of distant carcinoma cell metastases in lymph nodes of VX2 tumor-bearing rabbits.


METHODS
To obtain VX2 tumor micrometastases in right armpit lymph nodes of 12 male New Zealand white rabbits, VX2 tumors were implanted by hypodermal inoculation into the right anterior limb. Animals were randomly divided into therapy (n = 6) and control (n = 6) groups. (32)P-nanocolloid (0.5 mCi), 95% of which was >50 nm in diameter, was administered to the therapy group, and saline was administered to the control group. Injections were given once weekly for 4 weeks.


RESULTS
2-Deoxy-2[(18)F]-fluoro-D -glucose positron emission tomography revealed that the number of involved lymph nodes and the maximum standardized uptake value decreased in the (32)P-nanocolloid therapy group as compared with the baseline or saline control group (P < 0.05). The expression of the lymphangiogenesis factors vascular endothelial growth factors (VEGF)-C and VEGF-D by VX2 tumor cells present in lymph nodes was significantly lower in the therapy group as compared with the control group. Additionally, apoptotic VX2 tumor cell death was significantly greater in lymph nodes of the therapy as compared with the control group (P < 0.01). With the exception of a decrease in white blood cells of peripheral blood (P < 0.05), standard laboratory values were unaffected throughout the course of therapy with (32)P-nanocolloid.


CONCLUSIONS
These findings support treatment with (32)P-nanocolloid as a safe and effective approach for eradication of lymph node micrometastases.
Dong
Shengxiang
S
Department of Nuclear Medicine, Renji Hospital, Medical School of Shanghi Jiaotong University, No. 1630, Rd Dong Fang, 200127 Pudong New District, Shanghai, China.
Huang
Gang
G
Liu
Penan
P
Ma
Yubo
Y
Yan
Weili
W
Wan
Liangrong
L
Zhu
Changqing
C
D000818:Animals; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary*; D045744:Cell Line, Tumor; D003102:Colloids / Q000627:therapeutic use; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D008297:Male; D053758:Nanoparticles / Q000627:therapeutic use*; D010761:Phosphorus Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000627:therapeutic use; D016896:Treatment Outcome
D003102:Colloids; D010761:Phosphorus Radioisotopes; D019275:Radiopharmaceuticals