Conventional radiation therapy generally referred to as whole breast radiation therapy (WBRT), is delivered using a linear accelerator. Patients are typically treated five days a week during a five or six week period. While WBRT has been shown to be highly successful in keeping the cancer from returning, the benefits can be associated with a range of potential side effects including radiation delivered to nearby healthy tissue and organs such as skin, heart and lungs.
An international randomised controlled trial to compare TARGeted Intraoperative radioTherapy (TARGIT) with conventional postoperative radiotherapy after breast-conserving surgery for women with early-stage breast cancer (the TARGIT-A trial).
Today there is a Single Fraction Radiotherapy Option
Some women now have an option to receive an important new radiation treatment option called INTRABEAM intraoperative radiation therapy or IORT.
This innovative therapy is administered at the time of lumpectomy, following cancer removal. INTRABEAM IORT is delivered using a miniaturized radiation device which is inserted into the lumpectomy incision. Therapeutic radiation is then directed immediately and precisely right where it is needed most – the location where the cancer was removed. Localising the radiation inside the breast is effective because studies show that this is where cancer is most likely to recur.
INTRABEAM IORT is delivered as a 20 to 30 minute treatment under anaesthetic during surgery. This single fraction also minimizes radiation exposure to healthy tissue and organs.
Which patients can receive Intrabeam?
- Women over 45 years of age.
- Grade 1-2 ductal cancers less than 3 cm in size
- Lymph node negative
- Clear surgical margins
- Oestrogen receptor positive
What clinical testing was performed on INTRABEAM IORT?
Since 1998, the international TARGIT research group has been investigating this new method of delivering radiotherapy for breast cancer. The TARGIT-A trial is currently the largest multicenter randomized clinical trial for intraoperative radiotherapy (IORT) in the field of partial breast irradiation with 3,451 patients in 33 international centers. The study tested the effectiveness of an intraoperative dose of radiation delivered using the INTRABEAM System compared with up to six weeks of postoperative radiotherapy using conventional external beam radiation for the treatment of early-stage breast cancer. The TARGIT-A trial randomised half of the study group to receive conventional external beam radiotherapy (EBRT) while the other half was treated intraoperatively. 15% of the IORT group had high risk features and received extra EBRT as well. This reduced their usual treatment by 5 days though as it replaced their ‘boost’ treatment.
What were the results of the clinical trial?
The results of the TARGIT-A breast cancer trial show the overall number of recurrences of the cancer was very low.
In the patients treated at the same time as their cancer surgery, the local recurrence rates were 1.1% vs 2.1% 5 year local recurrence rates which sits inside the non-inferiority margin.. The breast cancer survival was equivalent between both treatment arms, however the non-breast cancer survival favoured Intrabeam treatment with less deaths secondary cancers and cardiac deaths. This is statistically significant. Lancet Nov 2013 online Vaidya et al.