Radiation therapy is a method of treatment of many neoplastic and some non-neoplastic diseases with ionizing radiation. Malignant cells’ DNA is injured affected by radiation therapy which causes a lot of mutations and leads to their death. Normal cells of the body do not undergo these changes because they are more resistant to radiation.
Radiation in breast cancer treatment is usually prescribed after surgery (adjuvant) to prevent a relapse of the disease.
Radiation therapy should be initiated after the post-operative sutures have healed. The optimal time is in 3 to 8 weeks. If chemotherapy was prescribed in the post-operative period, then the irradiation starts 3-4 weeks after chemotherapy is over.
Radiation therapy following breast-conserving surgeries is now the standard of breast cancer treatment and the chance of relapse has significantly decreased thanks to this approach. After the whole breast is removed (mastectomy) radiation therapy is only prescribed in cases of large tumors, if the tumor has been partially removed or when more than three lymphatic nodes are involved.
The duration and the dose of the radiation is calculated individually for each clinical case. On average, radiation therapy lasts around six-seven weeks and is prescribed in the dose of 50 Gy over the period of 25 sessions for the whole breast and (when necessary) for the lymphatic drainage pathways + Boost (additional irradiation of the tumor bed) in the dose of 16 Gy in 8 fractions. Overall, the patient receives 66 Gy of radiation over 33 sessions (visits) in the five days per week format.
At LISOD radiation therapy is performed with the modern VARIAN linear accelerators that provide doctors with extremely clear and detailed three-dimensional images and allow to adjust the exposure dose during the treatment.
On the whole it is an opportunity to deliver high doses of radiation directly in the breast and the tumor bed safely. Thanks to new techniques of 3D-conformal radiation therapy (IMRT, VMAT etc.) treatment has become even more effective. This also allowed to reduce the number of required radiation sessions, the duration of treatment and the likelihood of side effects – which is an additional benefit.
Another significant advantage for the LISOD patients is that radiation therapy is prescribed and performed by a team of professional, among them are radiation therapists, medical physicists, technologists, nurses with extensive experience. The Department of Radiation therapy is headed by an Israeli clinical oncologist, radiotherapist, world-renown doctor with more than 40 years of practice Zvi Bernstein. This powerful team guarantees efficacy and quality.
Hypofractionated radiation therapy
If lymphatic nodes are not affected, we usually recommend accelerated hypofractionated radiation therapy with high local doses following breast-conserving surgeries.
In such cases the whole breast irradiation lasts around 3 weeks (15 sessions up to 40 Gy).
Depending on the tumor’s biology, doctors at the multidisciplinary breast concilium can take a decision to increase the dose in the area of removed neoplasm (so-called Boost for 5 fractions of 2 Gy). In this case the course of radiation therapy lasts 4 weeks.
Accelerated partial breast irradiation (APBI)
The accelerated partial breast irradiation technique has shown to be an effective and safe radiation therapy method. The idea is to irradiate a limited amount of breast tissue which includes the removed tumor bed +2-2.5 cm.
The benefits of this technique are:
- it allows to increase the single dose of radiation;
- it shortens the duration of radiation therapy (full course of treatment lasts 2 weeks instead of 6-7 weeks);
- the risk of early and late radiation injuries decreases thus improving the quality of life.
Breast and lymph drainage pathways irradiation without Boost
In some cases when a high dose of radiation has to be applied to the tumor bed, but it cannot be identified during simulation (no radiopaque marks in the area of a removed neoplasm), or it is very large, and also when regional lymph nodes are irradiated, a decision may be taken to perform whole-breast radiation therapy with a dose of 50.4 Gy over 28 sessions (5.5 weeks).
Additional irradiation techniques
Intraoperative radiation therapy
Some oncological clinics perform intraoperative irradiation that complements postoperative external beam radiation therapy and shortens its duration but does not replace it.
During the intraoperative irradiation right after the tumor has been removed (before the wound is closed) the source of radiation is directed at the tumor bed with special devices and high-dose irradiation is performed (Boost). In many cases after the wound is healed, whole breast irradiation is needed.
Brachytherapy (contact irradiation) is an alternative to external beam Boost-irradiation of the breast. In this case a radioactive substance is delivered directly in the area of the removed tumor via a little plastic catheter under short general anesthesia.
Brachytherapy and intraoperative radiation therapy are not used at the LISOD Hospital, because they require general anesthesia and are invasive. According to data of many years of international research brachytherapy and intraoperative radiation therapy are not superior to modern techniques of external beam radiation therapy using VMAT, IMRT.