Accelerated partial breast irradiation treatment: Who needs it?
Simona Shaitelman, M.D.
Women with early stage breast cancer have so many different treatment options that the choices can be overwhelming. For almost all women who choose to keep their breast (and avoid mastectomy), radiation therapy is almost always a part of the treatment plan.
The radiation regimen for which we have the longest follow-up data involves treating the whole breast, every day for five weeks, typically with an additional one-week "boost" to the area where the tumor used to be.
For women who want the most conservative modality of radiation treatment, I recommend this longer course of treatment.
The question has become, as technology has improved, can we be more focal and efficient in how we deliver radiation therapy. Accelerated partial breast irradiation (APBI) lets me deliver relatively higher doses of radiation to the area where the tumor used to be, twice a day for five days.
This technique is still actively being compared to the traditional longer course of whole breast radiation. What we do have is follow-up data from multiple institutions in the United States and Europe that have shown very high rates of tumor control in appropriately selected patients, with 5-12 years of follow-up.
I use very strict criteria before offering APBI to patients and encourage all of my patients to be treated on protocol. The patients I treat with APBI have very early stage, small breast cancer that has been completely removed by their surgeon. I also evaluate each of my patients with a CT scan after surgery.
This lets me measure the exact dimensions of the area removed by the breast surgeon and to calculate if the patient can be suitably treated by one of the modalities we have available to deliver APBI.
How to receive APBI
At MD Anderson, we offer two main ways to deliver APBI to patients, one that's internal and one that's external.
Brachytherapy is a way to deliver very focused radiation inside the body in exactly the area where the tumor used to be. This technique takes advantage of the joint expertise of the breast surgeon and the radiation oncologist, and I enjoy being able to collaborate closely with my colleagues in breast surgery on these cases.
The surgeon places a catheter into the breast using local anesthesia in an outpatient setting. I then work with a medical physicist to design a treatment that is uniquely tailored to the anatomy of the patient. I'm present at each treatment my patients receive using a high-dose radioactive source that sits temporarily in the catheters.
Some patients tell me they prefer to not have a catheter placed inside the breast, in which case I offer APBI using external techniques including either protons or photons. These techniques use more than one beam of radiation to deliver focused treatment to the area surrounding where the tumor used to be.
My patients with early stage breast cancer have a lot of treatment options. I hope that in the conversations we have together that my patients can choose the treatment that fits them best.