Having the lymph nodes removed isn’t just for treatment, it is also for diagnosis. If they find a positive lymph node, they will keep removing until there is no cancer. I was having reconstruction at the same time,, my surgeon went through my breast incisions to get to my axilla. I am told the arm pit can be tender. Putting a small pillow under your arm can help.
Wishing you well!

Lymph Nodes/ Removal and Radiation are Separate issues. Effectiveness?
Lymph Nodes are evaluated with a process of uptake of dye in "Sentinel Node" dye uptake which are the first nodes to take up the dye are positive for cancer (none, one, or multiple nodes)
Radiation (Source-Mayo Clinic)
Radiation therapy for breast cancer uses high-energy X-rays, protons or other particles to kill cancer cells. Rapidly growing cells, such as cancer cells, are more susceptible to the effects of radiation therapy than are normal cells.

The X-rays or particles are painless and invisible. You are not radioactive after treatment, so it is safe to be around other people, including children.
Radiation therapy for breast cancer may be delivered through:
External radiation. A machine delivers radiation from outside your body to the breast. This is the most common type of radiation therapy used for breast cancer.
Internal radiation (brachytherapy). After you have surgery to remove the cancer, your doctor temporarily places a radiation-delivery device in your breast in the area where the cancer once was. A radioactive source is placed into the device for short periods of time over the course of your treatment.
Radiation therapy may be used to treat breast cancer at almost every stage. Radiation therapy is an effective way to reduce your risk of breast cancer recurring after surgery. In addition, it is commonly used to ease the symptoms caused by cancer that has spread to other parts of the body (metastatic breast cancer).

Sending Positive Vibes your way!

I had 3 removed, it healed without issues, and I have had no lymphedema in the 6 years since. It was really sore at first, the center had given me a u-shaped pillow to go under my arm. It helped keep pressure and friction on the site down, so it was more comfortable. A small folded towel will do the same. Hugs!

i had 5 nodes removed to check for cancer spread. All were negative. ive had no pain, only sore...so hopefully on the way to recovery!!!