Radiotherapy

If you have had your tumour removed surgically as a lump but not the whole breast (mastectomy), then adjuvant radiotherapy will treat with radiation the rest of that whole breast. 
 
If you have a lower risk of recurrence, it is possible to consider radiation to just part of the breast in the area where the tumour was removed.  For partial breast treatment you need to be low risk and meet certain criteria: 
 
– over 50 years old 
– tumour no bigger than 3cm 
– no lymph nodes containing tumour 
– tumour sensitive to hormone treatment  
– no evidence of tumour left at the edges of the surgical excision  
– just one single focus of tumour  
– not lobular pathology   
 
Your team will discuss with you whether you fit these criteria if partial breast treatment is an option. 
 
Leaving out radiotherapy completely may also be an option but this is usually considered only if you are at very low risk of recurrence.  Factors here include: 
 
– patients over the age of 70 years  
– tumour size less than 2cm  
– no lymph nodes involved  
– tumour sensitive to hormone treatment  
 
 If radiotherapy is to be omitted you would usually have 5 years of hormone therapy recommended.

Although the whole breast is removed at mastectomy, adjuvant radiotherapy may be recommended for the chest wall (or over the reconstructed breast if an immediate reconstruction operation was performed at time of mastectomy).  

This is usually considered if: 
– the primary tumour was larger than 5cm;  
– or extended into skin or muscle;  
– or if in surgically removing the lymph nodes in the armpit four or more were found to contain tumour;  
– or if the edge of the surgical specimen removed was less than 1mm from the edge of tumour as this may mean higher risk of tumour cells left behind. 
 
With between one and three lymph nodes containing tumour but in combination with other high risk factors such as lack of hormone receptors or high ‘grade’ disease, adjuvant radiotherapy after mastectomy may be discussed as an option. 

Adjuvant radiotherapy to the axilla may be considered even after all the axillary lymph nodes have been removed surgically (axillary node clearance). This is done if four or more lymph nodes contained tumour or if one to three nodes contained tumour, but you have other risk factors such as having had neoadjuvant chemotherapy or if you have a high-grade tumour.

Following breast conservation surgery as well as treating the whole remaining breast with adjuvant radiation, there may be benefit to considering an additional ‘boost’ to increase the dose given to the immediate resection site if there is a higher risk of local recurrence in that area.  This will be considered if you are under the age of 50 or  over 50 but with high grade disease or if you had tumour infiltrating skin at diagnosis. 
 
The boost dose may be given at the same time as the whole breast dose or can be added on as extra treatments to that smaller area after completion of the main breast dose. 

The total radiation dose delivered is divided into ‘fractions’ which are smaller doses usually given each day Monday to Friday. 
 
Standard breast radiotherapy is most commonly given as 5 fractions over a one-week period. 

Following breast reconstruction or if nodal areas require radiotherapy the treatment schedule is usually 15 fractions over a three-week period.