Intraoperative radiotherapy and early breast cancer

Dr Yastira Ramdas, a radiation oncologist, educates us on how intraoperative radiotherapy is performed.

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Traditionally when a patient presents with early stage breast cancer whilst simultaneously meeting certain criteria, it may allow treatment by surgical removal of only the lump, and lymph nodes located under the armpits. Thereafter it’s daily radiation treatments, for multiple weeks.

This method of treatment avoids a mastectomy but is equally effective and has the added benefit of breast conservation. Radiotherapy is given to the whole breast for four to six weeks. 

Over the last few years, a novel device has been developed which delivers radiotherapy, accurately targeted to the tumour bed, in the operating theatre. This technique is referred to as Targeted Intraoperative Radiotherapy (TARGIT).

The history of intraoperative therapy

Intraoperative radiotherapy (IORT) dates to the 1980s. It’s primarily aimed as a treatment modality for early stage breast cancers and is administered as a single high-dose fraction of radiation directly to the tumour bed post-surgery.

Reported benefits include fewer side effects by reducing radiation exposure to surrounding healthy tissue, more convenient as it can replace the traditional six-week external radiation beam regiment and is less expensive³.  

Numerous studies detail the benefits of IORT, with the landmark study by the College of London: involving 33 centres in 11 countries, accruing 1721 patients, proving the non-inferiority of IORT as compared to traditional radiotherapy treatments⁶.  

Who can have IORT?

When selecting patients for IORT modalities, guidelines include: 

• Age greater than 50 years of age (potential for 40-49 years)
• Tumour size less than 3cm 
• Negative nodal status and other factors⁵

Procedurally before considering IORT treatment regimes, a patient will present with early stage breast cancer (Luminal A type), detected by imaging or examination, a confirmation sentinel lymph node biopsy is performed to confirm negative lymph nodes along with other applicable factors. 

The patient is assessed by specialist surgeons and a radiation oncologist. They discuss applicable treatments, advantages, disadvantages, and funding. If IORT is selected, informed consent is garnered.  

The surgery date is booked, the multi-disciplinary team further assess the patient’s IORT regiment prior to treatment and finally the IORT is performed in theatre. Post-treatment follow-up is then conducted.  

How is intraoperative therapy performed?

IORT is a form of accelerated partial breast irradiation (APBI) that involves a team of specialists delivering radiation at the same time of surgery, while the patient is still under anaesthesia. 

Once a tumour is removed during surgery, a round applicator is fitted and carefully positioned in the tumour cavity, where low-energy X-rays are applied to the breast tissue closest to the tumour. This eliminates lingering cancer cells, reduces side effects, spares remaining breast tissue and nearby organs from radiation exposure. The process takes less than an hour and allows patients to have fewer radiation treatments and potentially fewer treatment-related side effects.

Advantages

• The entire course of radiation can be delivered at one time. The “traditional” radiation schedule for breast cancer is five days a week for up to six weeks. IORT saves time and is more convenient for the patient. 
• The radiation dose applied during IORT is much smaller as compared to external beam radiotherapy. 
• Nearby normal organs and tissues receive less radiation from the IORT device.
• If necessary, the patient can have another lumpectomy if another tumour is found in the breast in the future. 
• IORT costs significantly less than external beam radiotherapy.

Disadvantages

• Fluid accumulation in the lumpectomy cavity (seroma) – very rare as the surgeon leaves chest drains in.
• Reddening of the skin (erythema) only if the applicator is too close to the skin.
• Rib fracture (extremely rare).

IORT in SA 

In SA, acceptance rates of IORT among clinicians is low due to lack of awareness, reduced IORT expertise and lack of facilities in Africa. This is a contrast to developed countries where adoption rates are increasing and is increasingly bolstered by the growing body of peer-reviewed research, detailing efficacy as compared to traditional radiation treatments. 

These low adoption rates are mirrored by local medical aids which has resulted in patients funding IORT treatment modalities out of pocket.  

The Breast Care Centre at Netcare Milpark is the only certified IORT treatment Centre in Africa and has to date performed over 150 successful procedures.