Radical surgery, also called radical dissection, refers to the removal of blood supply, lymph node

Lymph node

A lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...

s and sometimes adjacent structures of a diseased organ

Organ (anatomy)

In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...

 or tumor

Tumor

A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

 during surgery

Surgery

Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...

. In surgical oncology

Oncology

Oncology is a branch of medicine that deals with cancer...

, radical surgery typically describes the removal of a tumor or mass and ancillary lymph nodes that may drain the mass for diagnostic and/or treatment purposes, as in radical mastectomy

Radical mastectomy

Radical mastectomy is a surgical procedure in which the breast, underlying chest muscle , and lymph nodes of the axilla are removed as a treatment for breast cancer....

. http://medical-dictionary.thefreedictionary.com/radical+dissection