Radiotherapy has entered the standard treatment of breast cancer. Dr. William Casagrande, specialist in Radiotherapy in Milan, talks about it
What is Radiotherapy?
Radiotherapy is a medical therapy that uses ionizing radiation for the treatment of tumors. The radiations are produced by a machine (linear accelerator) and interact with the tumor cells, leading to cell death through alterations of chemical bonds, molecular bonds and DNA (direct action), as well as by the creation of free radicals (indirect action) ).
Radiotherapy and breast cancer
In breast cancer, Radiotherapy can be used as an adjuvant therapy, ie after surgery to remove the tumor with breast conservation (conservative surgery or quadrantectomy). Radiotherapy has become part of the therapeutic process as it reduces the occurrence of local recurrences, with a percentage that can reach 60% and with relative increase in survival.
Another indication to Radiotherapy is after a surgical procedure to remove the entire breast (total mastectomy), in the presence of large tumors that could also affect the pectoral muscle or the dermis. In this case, Radiotherapy is performed on the chest wall and often also on the lymph nodes contiguous with the disease (axillary and clavicle).
Radiotherapy can also be used as an exclusive therapy when there are contraindications to subject the patient to surgery.
Are all patients eligible for Radiotherapy?
In the past, no indication was given to radiation therapy after quadrantectomy for small tumors (carcinoma in situ). On the other hand, recent studies have shown that patients who were not also subjected to radiotherapy developed a local recurrence in 35% of cases, a percentage that is halved by the use of postoperative radiation therapy.
A contraindication related to radiation therapy occurs in the presence of collagen diseases (eg scleroderma) or autoimmune diseases with cutaneous manifestations (eg Lupus) in the acute phase.
In the past, even older patients tended to be excluded, unlike today where age is no longer a contraindication since the life expectancy is longer.
What is Radiotherapy?
First of all, we clarify that we are talking about external beam radiotherapy.
After the first visit, if there is an indication to Radiotherapy, the patient will have to perform a center CT scan, which is not a diagnostic procedure and does not require contrast liquid. The patient's treatment plan is personalized and is elaborated on the basis of the three-dimensional anatomical information provided by this TAC. Then, small tattoos will be made on the patient's skin, so that it is always placed in the same position on the treatment machine every day.
The standard protocol includes a cycle of Radiotherapy on the entire breast possibly followed by a further dose of radiation (boost) where the tumor was located: it is at the site of the tumor removed, in fact, which often shows the local recurrence (80% -90 %). Usually, we talk about 25 sessions per day plus 5 sessions of boost on the operating bed.
Based on the patient's characteristics and clinical history, the Radiotherapist can choose whether to use a so-called hypofrazionato protocol, which has the peculiarity of delivering a dose of greater daily radiation, but in a reduced number of sessions (usually 15).
Radiation therapy for breast cancer: side effects
The possible acute side effects produced by Radiotherapy are mainly related to a toxicity that concerns the skin (erythema). There are some ointments to be applied locally to reduce erythema. In 20-30% of cases you can have a mastitis, that is the inflammation of the mammary gland. In this case, anti-inflammatory drugs are used.
Another possible side effect, much rarer, is that of radiation pneumonitis (5% risk), a non-symptomatic pathology, which can have sequelae only in the case of bacterial superinfection.
If the irradiated breast is the left one, there is a low risk (less than 3%) related to cardiac toxicity. However, this risk may increase in those patients who have previously had cardiotoxic adjuvant chemotherapy.
Eventual late effects, finally, are related to cosmetics. Radiotherapy can lead to fibrosis of the irradiated breast which results in a decrease in breast volume and a reduction in its elasticity.
It should be noted that any side effects listed can still be resolved with the appropriate medical treatment. In addition, modern accelerators are equipped with image acquisition systems aimed at checking the correct positioning of the patient before the therapy session, allowing a more precise irradiation and thus minimizing any side effects, especially the most harmful ones.
Among the late effects in the case of irradiation of the lymph node regions at risk (axillary and clavical region), an increase in the probability of developing swelling (lymphedema) of the arm should be reported, especially after surgical dissection of the axillary lymph nodes. Also for this eventuality the use of preventive and rehabilitative therapies (lymphatic drainage) is foreseen that limit both the appearance and the persistence.
Radiation therapy for breast cancer: the advantages
As for the advantages, the most important is the reduction of the probability of local recurrence (variable in relation to the histological characteristics of the tumor).
Many studies, over the years, have shown that improving the local control of the disease is equivalent to increasing the survival of patients but also to improve their quality of life.
During breast radiotherapy, patients at the end of the session:
- They can immediately return home;
- They can perform normal daily and work activities;
- They can be in contact with people of any age
- They do not lose their hair;
- They do not need to be accompanied;
- They can drive
- They do not have a particular diet to follow.
Editor Karin Mosca