Single Dose Therapy

Single-dose radiation therapy during operations

Intraoperative radiation therapy (IORT) permits the delivery of a single dose of radiation during surgery for breast cancer. This eliminates the need for postoperative radiation therapy. If required by physicians, additional doses of radiotherapy can be applied.

Following the surgical extraction of a breast tumor, a high dose of radiation is delivered to the precise area that needs treatment, and the surrounding healthy tissues are protected. This eliminates the need to return to the hospital for daily treatment and offers patients psychological comfort.

What is single-dose radiation therapy?

In patients with breast cancer, radiation therapy can be completed with a single-dose application using the IORT method during surgery. Once the tumor in the breast is removed, the special applicator in the tool is placed in the tumor area. Based on calculations, a high dose of radiation is given only to this area. This completes all local treatments and protects the healthy tissue.

How is traditional radiotherapy applied?

Radiation therapy is carried out in specially protected rooms in hospitals in the Radiation Oncology department using linear accelerators that produce photons and electrons. In almost all breast cancer cases that have been treated with protective surgery (in which the portion of the breast with the tumor is removed and the rest of the breast is left intact), radiotherapy is needed following the operation.

Radiotherapy begins preferably after chemotherapy for patients who require it or at least three weeks after surgery for patients who are only treated with hormone therapy. Before receiving radiotherapy, tomography cross-sections in 2 mm increments are taken using a computer for planning purposes. Later, arrangements are made to apply the necessary dose of radiation to the at-risk areas in the breast while protecting the healthy organs, including the heart, main arteries of the heart, lungs, and the other breast, where the illness has not spread. Once the plan is approved, the patient receives radiation treatment for 5–7 weeks, depending on the condition of the illness, as determined by the radiation oncology doctor. However, some patients receive a short-term treatment called hypofraction, which lasts three weeks.

Advantages of single-dose application

Single-dose application with the IORT tool utilizes a linear accelerator, in much the same way as traditional radiotherapy. It is used in an operating room using a safe and portable tool that operates in a linear and accelerated manner, which produces electron energy without requiring as much protection for the personnel as traditional linear accelerators. In addition to the surgical team carrying out the operation, a radiation oncology specialist and a medical physicist are present in the operating room. In this way, radiotherapy is completed at the same time as the surgery. A significant advantage for the patient is that there is no need to wait for the wound to heal following surgery or to plan radiotherapy and visit the hospital each day for treatment. The total duration of the treatment is greatly reduced.

During the operation, once the tumor in the breast is removed, the special applicator within the tool is placed in the area where the tumor was. A high dose of radiation is given only in this area, completely protecting the healthy tissue. Although the single-dose application and other methods that apply radiation only to the tumor area, as opposed to the entire breast, have become more widely accepted in recent years, the single-dose application is not for every patient. The decision on whether this treatment is suitable for the patient must be made by the radiation oncologist, the surgeon, and the pathologist dealing directly with the patient. The patient’s age, the size of the tumor, and other pathological qualities of the tumor play an important role in this decision.

Who should receive a radiation boost?

Patients under the age of 50–60 years are not considered ideal candidates for a single-dose application. For these patients, it is necessary to apply radiation to the tumor area following the application of radiation to the entire breast using the traditional method. Once the treatment of the entire breast area is completed (25–28 working days), the area from which the tumor was removed is treated with radiation for an additional 5–8 working days, depending on the patient. Applying radiation to the area from which the tumor was removed is called a radiation boost.

Applying radiotherapy to the nipple complex

Breast-protective surgical treatment may not be suitable for some patients. If the entire breast needs to be removed, the nipple and its surrounding area are left intact for a satisfactory cosmetic result. This is called a nipple-sparing mastectomy. A single dose of radiation is applied to the nipple and the tissue underneath using the IORT method to decrease the risk of recurrence. The radiation boost has been offered in Turkey for the first time at the Acıbadem Maslak Hospital Senology Center.