Long-Term Results from the TARGIT-A Clinical Trial Show Significant Improvements for Breast Tumor Treatment with Use of Intraoperative Radiation Therapy

The latest results from the international TARGIT-A clinical trial have just been published in the International Journal of Radiation Oncology, Biology and Physics*. This is a study focused on long-term local control and survival rates for breast cancer patients treated with TARGIT (intraoperative radiation therapy using the INTRABEAM® system), compared to patients treated with external radiation therapy.

It has been demonstrated that the dispersed radiation that accompanies full breast irradiation during external radiation therapy can induce development of other types of tumors (lung, stomach, etc.), in addition to increasing the risk of heart attacks, especially in smokers. Through treatment with a single, more localized dose, such as by intraoperative radiation therapy using the INTRABEAM® system produced by Carl Zeiss Meditec, which incorporates the Radiance™ planning software from GMV, immediately following a lumpectomy (surgery that removes the cancer and other abnormal breast tissue, along with a small amount of normal tissue surrounding it, but not the breast itself) produces better tumor control efficacy and a lower mortality rate.

As explained by Carlos Illana, head of Secure e‑Solutions at GMV, «this clinical trial was conducted with 2,298 patients and up to 19 years of follow‑up, with an average of 8.6 years, so the results are considered to be very solid». It is worth emphasizing that when assessing the efficacy of any cancer therapy, it is of special interest to be aware of the progression-free survival rate as well as the overall survival rate. In relation to this, and as demonstrated by the graphs produced during the clinical trial, «with external radiation therapy, the probability of death in the case of local recurrence is a little over four times as high, and the probability of death from causes not due to the cancer is approximately double, compared to treatments performed using intraoperative radiation therapy».

In addition, the trial has concluded that for patients with early-stage breast cancer, targeted, single-dose intraoperative radiation therapy (IORT) applied during the tumorectomy surgery can avoid the toxicity and other undesirable effects that may be caused by radiation therapy applied to the entire breast after surgery (such as with external radiation therapy). Use of IORT also reduces pain, generates improved quality of life, and leads to better results cosmetically. Furthermore, the patient does not need to travel as with conventional treatment (such as when it involves six weeks of daily doses, Monday through Friday). This reduces the patient’s emotional stress, with the corresponding impact on quality of life while also reducing the associated carbon footprint in the patient’s country.

In a detailed analysis of subgroups, the 12-year survival rate was 4.4% higher with TARGIT‑IORT for patients with grade 1 and grade 2 cancer, which includes the majority of patients. For the rest, the survival rate results were comparable in the two groups (but still with the advantages of intraoperative radiation therapy described above).

Multiple initial, non-randomized trials have been published regarding the use of TARGIT‑IORT, with similar results seen in more than 3,000 patients treated using that approach in France, Germany, Denmark, Switzerland, and other countries. In 2019, approximately 260 healthcare centers in 38 countries had treated over 45,000 patients using TARGIT‑IORT.

The basics of TARGIT

Targeted single-dose intraoperative radiation therapy (TARGIT‑IORT) is a treatment applied just after tumor removal, focused on the tissues surrounding the tumor area.

Even after the tumor has been surgically removed from the breast, it is been observed that when surgery is used as the only treatment, there is a higher risk of local recurrence in the tumor location (relapse). It has been demonstrated that applying a high dose of radiation in the area surrounding the tumor using IORT, correctly planned using the Radiance™ software, is not only an effective treatment, but in many ways it is better than other therapeutic alternatives for breast cancer during its initial stage. The results show that for selected cases, this should be considered as the new standard treatment for early-stage breast cancer.

Radiance™, the market’s only radiation-surgery planning system

The Radiance™ radiation-surgery planning system, developed by GMV, allows estimation of the dose to be given in relation to effects on at‑risk organs, and it therefore provides control over the treatment’s side effects, potentially reducing the risk of induced tumors and heart attacks. In this way, use of Radiance™ provides increased safety for intraoperative radiation therapy, giving the specialists a full analysis of the patient, and assisting with the ability to make decisions prior to surgery by identifying the optimal treatment and adapting it to each specific case.

The algorithms used by the Radiance™ software provide all of the information necessary to document the surgery in advance, with calculation prior to the surgical procedure of the radiation therapy parameters that the specialist should apply in the operating room. It also provides high-quality multiplanar reconstructed (MPR) images and a three-dimensional (3D) view of the patient, allowing for simulated visualization of the treatment outcome.

The benefits provided by Radiance™ help reduce the risk of recurrence in a wide range of tumor types, including among others those seen in breast cancer, and its palliative value is also significant in cancers that are difficult to cure such as pancreatic cancer, and for situations of cancer relapse.

Cancer Radiation Therapy Day

Currently, 3 out of every 10 patients who need radiation therapy do not receive it, either because of a lack of equipment or because of its geographical distance from them. There are cases of patients who must travel up to 200 kilometers each day to receive radiation therapy. This situation could be mitigated by applying intraoperative radiation therapy during surgery.

As another anniversary approaches of the first documented cure using radiation therapy, which occurred on December 19, 1899, GMV is joining the Spanish Cancer Radiation Therapy Society (SEOR) in recognizing Cancer Radiation Therapy Day in Spain.

For this purpose, SEOR has launched a campaign known as «Yo sé decirlo» («I know how to say it»), which pursues the goal of raising awareness in the community regarding the importance of radiation therapy in cancer treatment. For more information: www.seor.es/yosedecirlo

*International Journal of Radiaton Oncology, Biology and Physics. Volume 115, number 1, pages 77‑82, January 2023. The TARGIT-A Randomized Trial: TARGIT-IORT Versus Whole Breast Radiation Therapy: Long-Term Local Control and Survival - International Journal of Radiation Oncology, Biology, Physics (redjournal.org)