[Distribution and depth of internal mammary lymph nodes in breast cancer].

Lymphoscintigraphy was performed in 50 cases of breast cancer using 99mTc-colloid as a tracer. The results indicated that 277 lymph nodes, 128 on the right side and 149 on the left, were imaged. Most of the lymph nodes were located in the second and third intercostal spaces. The mean distance between these lymph nodes and mid line was 1.93 +/- 1.05 cm-2.70 +/- 0.93 cm. The mean depth was 2.42 +/- 0.52 cm-3.07 +/- 0.72 cm. It was over 4.0 cm in isolated cases. The lymph nodes which were not showed after repeated examination could have been involved by the cancer. Radionuclide lymphoscintigraphy, being safe, easily repeated and having low radiation dose and good image, is very useful for radiotherapy.