Comparing partial breast irradiation and whole breast irradiation in patients with breast cancer

This article looked at the use of partial breast irradiation (PBI) versus whole-breast irradiation (WBI) as a treatment for breast cancer (BC). The authors found that PBI offered similar results when compared to WBI. 

BC remains one of the most common forms of cancer found in women. Standard care for BC remains chemotherapy, surgical removal of tumors, and radiation therapy. WBI has previously been used as a conventional radiation therapy. This involves delivering 25 sessions of radiation over the whole breast.

Recently, PBI has been suggested as an alternative treatment approach for patients with early BC. This involves delivering a lower dose of radiation in 5 sessions over 5 consecutive days only in the area where the tumor was. This is thought to shorten treatment times and reduce the rates of side effects. There are several different techniques used for PBI such as using an external source of radiation (external beam; EB) or the insertion of radioactive material into the breast tissue (brachytherapy; BT). 

There have been trials that evaluated the effectiveness and safety of WBI and PBI in patients with BC having breast-conserving surgery (BCS). However, the long-term effectiveness and safety of PBI versus WBI remain controversial and the different PBI techniques used have not previously been examined.

This article analyzed the results of 7 different studies including a total of 9758 patients. Half of these patients received WBI and half PBI after BCS. Patients in the PBI group had either EB or BT. The minimum follow-up was 5 years. 

There were no significant differences between WBI (1.7%) and PBI (1.8%) in the rate of recurrence at 5 years. In the PBI group, the 5-year recurrence rate was 1.7% for EB versus 2.2% for BT. 

Short-term skin toxicity was experienced by 7.1% in the PBI group compared to 40% in the WBI group. Long-term skin toxicity was 0% in the PBI group compared to 1% in the WBI group. 

The authors found that PBI and WBI have similar recurrence rates, while PBI reduced the risk of short-term side effects.