Intraoperative Radiation Therapy (IORT)

Intraoperative radiation therapy is a new form of radiotherapy (radiation therapy) used mostly in the treatment of breast cancer. Radiation therapy has been used for many years to treat various cancers, which is performed based on the type of tumor and its stage of development. The therapeutic procedure consists of using X-rays to reach the cancer and destroy the cancerous cells. The rays can be photons or electrons, depending on the condition being treated. These various types of rays are sometimes associated. This is why for the same treatment a patient can be placed under different devices: cobalt therapy devices or linear accelerators.

Radiation therapy is usually recommended in the treatment of breast cancer after surgery, preoperative radiotherapy; or before the surgical procedure to make possible the operation, postoperative radiotherapy. Regular radiotherapy usually takes weeks to complete. Finally, a new form of cancer treatment that allows a patient to undergo surgery and radiation simultaneously: Intraoperative radiotherapy or Intraoperative radiation therapy.

Thanks to intraoperative radiation therapy, a health care professional can irradiate a target tumor during a surgery, either directly or the site where the cancer was before its removal in order to kill remaining cancer cells. RTPO applies to breast, colorectal, colon, pancreas and brain cancer. Often given as a single dose, intraoperative radiation therapy can also be preceded or followed by several weeks (usually three to seven) of external radiation therapy. Treatment protocols vary by practice guidelines.

Advantages and Disadvantages

Intraoperative radiation therapy causes fewer side effects than standard radiotherapy. It is one of accelerated partial breast irradiation techniques (APBI), which also includes short concentrated doses of brachytherapy and radiotherapy, recommended mostly in cases where the oncologist does not want to irradiate the entire mammary gland to treat a breast cancer of good prognosis. Another advantage of Intraoperative radiation is the ability to substitute one session for the usual 33.  An additional benefit is the fact the therapy is more economical in terms of time and money.

Although RTPO offers many advantages, its effectiveness on avoidance of local recurrence remains unproven. In addition, it can be used in limited types of patients, aged 50 to 70 years, diagnosed with small tumors less than 1 cm, hormone-dependent, lymph nodes not affected. On a practical level, Intraoperative radiation therapy lengthens the time of surgery, affects aesthetic sequelae, and others.

All results of recent intraoperative radiotherapy remain positive, which give some scientists no reason to doubt that the technique will benefit patient. But they remain assertive. In addition, validate a new therapeutic approach requires time and large studies.

The results of two clinical trials involving large random samples using two different radiation sources provide new data on the clinical efficacy of intraoperative radiotherapy and its safety as adjuvant therapy after lumpectomy (tylectomy) for early-stage breast cancers. However, extensive criticism on the protocols of the trials and the results achieved underline the need for longer-term follow-up, and more precision on the criteria for selection of patients who are qualified for the therapy.

As regards the use of Intraoperative radiation therapy for the treatment of colorectal cancer, there are few high quality studies, which makes it difficult for health care professionals to apply the therapy on their patients. Some scientists conclude that so far the effectiveness of intraoperative radiotherapy to rectal cancer and colon cancer has not been demonstrated convincingly. As brain and pancreatic cancers, recent explorations confirm the need to conduct more studies and phase III trials, some of which are planned or underway.

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