A new clinical trial for breast cancer, recently published in The Lancelot, demonstrates that a single fraction of targeted intraoperative radiotherapy (TARGIT) administered with the ZEISS INTRABEAM® at the time of lumpectomy is in no way inferior to standard external beam radiation (EBRT) delivered over three to six weeks following breast conserving surgery, for a select group of patients.
“The most important benefit of TARGIT for a woman with breast cancer is that it allows her to complete her entire local treatment at the time of her operation, with lower toxicity to the breast, the heart and other organs. Our research supports the use of TARGIT concurrent with lumpectomy, provided patients are selected carefully, and should allow patients and their clinicians to make a more informed choice about individualizing their treatment, saving time, money, breasts, and lives," said Professor Jayant S. Vaidya, FRCS MD, PhD from the international TARGIT investigators group.
Since 1998, the international TARGIT research group has explored whether radiotherapy targeted to the tumor site at the time of surgery can reduce the risk of recurrence in early breast cancer as efficiently as the standard three to six week EBRT.
Customarily, whole-breast EBRT is given following lumpectomy (breast conserving surgery) to reduce the risk of recurrence of cancer in the breast and of breast cancer mortality. EBRT usually is administered over a course of three to six weeks requiring patients to receive treatment at radiotherapy centers for 20-30 days. In some cases, women eligible for breast conserving surgery, but residing quite a distance from a radiotherapy center and unable to attend daily post-surgical treatments may even undergo mastectomy as a second option.
In the TARGIT technique, during surgery following excision of the tumor, the affected tissue in the tumor site is irradiated from within the breast using the ZEISS INTRABEAM. The TARGIT study results reveal that targeted intraoperative radiotherapy delivered with ZEISS INTRABEAM can significantly reduce the risk of recurrence of the cancer as successfully as a standard three to six week course of whole breast irradiation in selected women with invasive ductal carcinoma.
The TARGIT-A trial has been noted to be 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 across Europe, the United States, and Australia. The TARGIT-A trial followed an individualized risk-adapted approach, meaning, that patients who had undergone TARGIT at the time of surgery showed in the final pathology additional unexpected risk factors, were given supplemental EBRT, which was the case for around15% of the patient population.
The 5-year results for local recurrence and the first analysis of overall survival of the TARGIT-A trial have now been reported. When comparing TARGIT with EBRT the difference in 5-year local recurrence between the two treatments was less than 2.5% and consequently considered "non-inferior" to standard EBRT (daily doses for 3-6 weeks) in treating the cancer. Overall mortality was 3.9% with TARGIT and 5.3% with EBRT, due to fewer deaths from cardiovascular causes and other cancers.
"TARGIT concurrent with lumpectomy within a risk-adapted approach should be considered as an option for eligible patients with breast cancer carefully selected as per the TARGIT-A trial protocol,” the study authors eventually concluded based on the statistical information of breast cancer recurrence, number of deaths, and side effects of TARGIT vs. EBRT.
"We commend the international TARGIT group pioneered by Professor Jayant Vaidya and Professor Michael Baum for this outstanding research on this new treatment option that can benefit many breast cancer patients. The TARGIT group's research will further enhance adoption by radiation oncologists and breast surgeons worldwide and will broaden the application of our ZEISS INTRABEAM for this new option in the fight against cancer," said President and CEO of Carl Zeiss Meditec AG, Dr. Ludwin Monz .
