4.4.3　Main Points of Surgery

（1）Tracer injection site blue dye and radionuclide tracers injected in the original swelling around the breast essence，tumor surface inside or subcutaneous，mastumpal area inside or under the skin have similar success rate and false negative rate，but each has its own characteristics.The intracutaneous injection of tracer dispersion is dispersed more rapidly，which can shorten the time between the start of the operation.Under-mast injections can be used for clinically untouchable tumors.When the tumor is located on the phenoty outside the breast，the injection point is kept away from the armpit，reducing the interference of blue dye dispersion and radionuclide scattering.Injection of the breast essence around the tumor can be used for the study of SLN in the breast region of breast cancer.In clinical practice，the injection site of SLNB tracer can be designed individually.(https://www.daowen.com)

（2）Whether it is mastectomy or breast preservation surgery，SLNB should precede breast surgery.The determination of SLN in surgery varies depending on the tracer.The dye method requires the detection of the first blue-dyed lymph nodes entered by all blue-dyed lymphatic tubes，and careful detection of all blue-dyed lymphatic tubes is the key to avoiding SLN slout and reducing false negative rates.The threshold forradionuclide SLN is more than 10%of the maximum count of lymph nodes alllymph nodes，and the inoperative gamma detector probe should move slowly，detect in an orderly manner，and be close to the count.With the deepening of SLNB research，the value of tracing as a tracing agent to detect SLN effective supplement has been affirmed，the application of blue dye and/or radionuclide detection SLN detection of SLN should be carried out in the armpit area of the touch diagnosis，touch diagnosis found that the swelling，hard lymph nodes should also be sent as SLN alone.The principle is that when SLN and its input lymphatic tube are completely occupied by the tumor，the tracer cannot reach the SLN，and the use of tracing method can avoid the omission of the positive SLN and effectively reduce the false negative rate.