Brachytherapy

Generality

Brachytherapy, or internal radiotherapy, consists in placing a radioactive source in direct contact with the tumor. This form of treatment has the advantage of exposing only the affected anatomical area to radiation, thus sparing the surrounding healthy tissues. Furthermore, it is carried out very quickly and with few therapeutic sessions.

Picture: an "interesting diagnostic image of the pelvic area, which shows the radioactive sources (in this case seeds similar to rice grains) inserted inside the body, to treat a tumor. From the site: abitarearoma.net

The procedure can be carried out in different ways, depending on how the tumor looks (location and size) and the patient's health condition.

What is brachytherapy?

Brachytherapy is a type of radiotherapy in which radioactive material is placed inside the body, near the tumor to be treated. This explains why brachytherapy is also defined as internal radiotherapy.
The radioactive material, composed of radioisotopes, can be applied to cylindrical supports, small spheres or seeds similar to rice grains (the choice depends on the needs), then implanted in the most appropriate place to act as an internal source of radiation. These radiations serve to destroy the cells that make up the growing tumor mass.

ADVANTAGES OF BRACHITHERAPY

There are three main strengths of brachytherapy.
The first advantage is to guarantee "limited exposure to radiation and less damage to healthy tissues: in fact, unlike what happens with external radiotherapy (which affects an extended area of ​​the body), internal radiotherapy" only works on " area occupied by the tumor.
The second advantage is connected to the first and consists in the possibility of increasing the dose of radioactivity emitted by the source, as this is directed exclusively against the tumor mass. In reality, as will be seen later, the quantities of radiation emitted are not always high: in some cases, in fact, a treatment at lower doses, but very prolonged, is opted for.
Finally, the third advantage concerns the speed of treatment. While external radiotherapy takes place in many sessions (the time that separates them, moreover, allows the residues of the tumor to resume growth), brachytherapy is immediate and rapid. As will be seen, it does not require special instruments and allows the patient, in some cases, to undergo the treatment and, at the same time, continue in their daily activities.

When you do

Brachytherapy is used for the treatment of various cancers, which affect:

• Biliary tract
• Otherwise
• Uterine cervix
• Endometrium
• Eyes
• Brain and, in general, the head and neck
• Lung and respiratory system in general
• Prostate and penis
• Urinary system
• Colorectal
• Skin
• Various soft tissues
• Vagina and vulva

Brachytherapy, like external radiotherapy, is a treatment that can be practiced alone or in combination with other anticancer treatments. For example, in cases of tumors accessible to the surgeon, brachytherapy can be used to complete a first surgical removal; in cases of inoperable neoplasms, on the other hand, internal radiotherapy can represent the only feasible solution.
Sometimes, it is possible that brachytherapy and external radiotherapy are used simultaneously to obtain a better therapeutic result.

The side effects

Since, albeit to a limited extent, brachytherapy exposes to radiation, it can also produce other side effects, of a general and specific type.
General side effects: they are swelling and pain in the area where the radioactive source is positioned.
Specific side effects: they depend on the tumor in question and on the area in which it arises. To know, in detail, the consequences of the treatment, it is advisable to consult your doctor.

Preparation

Before starting brachytherapy, the patient with cancer must undergo several diagnostic tests, such as computed tomography (CT) and nuclear magnetic resonance (MRI), to define the location and size of the tumor.
Once in possession of these data, an oncologist radiotherapist will plan the most appropriate therapeutic path.

Details of the procedure

As mentioned, brachytherapy involves placing a radioactive source close to the tumor. This procedure can be carried out in various ways, depending on the size of the tumor, its location and the patient's state of health.
The three parameters reported below serve to distinguish the various types of brachytherapy, however, as the reader will note at the end of the discussion, this distinction is only formal. The only factors that influence the procedure are the characteristics of the tumor and the condition of the patient.

• Location of the radioactive source
• Intensity of radioactivity
• Duration of treatment

PLACE OF PLACEMENT: INTERSTIZIAL OR CONTACT BRACHITHERAPY

Depending on where the radioactive material is placed, brachytherapy can be interstitial or contact.

• In interstitial brachytherapy, the radioactive sources are inserted directly into the tissue affected by the tumor. These sources are usually spheres or small seeds, similar to grains of rice; their precise placement is done through needles, catheters or special applicators, with the help of diagnostic imaging instruments (CT or ultrasound). The most suitable time to place the sources depends on the tumor and its severity: in severe neoplasms, in which the surgeon cannot completely eliminate the tumor mass, it is possible to apply seeds or spheres already at the end of the surgery.
  Examples of tumors for which the so-called interstitial brachytherapy is foreseen are breast and prostate neoplasms.
• In contact brachytherapy, the radioactive sources are inserted in the spaces close to the target tissues, usually body cavities but not only, since this method is also used for the treatment of skin cancers. Radioisotopes are released from cylindrical or tubular supports (cylinders or tubes), placed directly by the surgeon's hand or by computerized machinery. Also in this case, for the correct execution of the procedure, the guidance of diagnostic tools, such as CT scan and ultrasound, is required.
  Some examples of tumors treated with contact brachytherapy are those of the uterus, cervix, vagina, skin or digestive system (see table).

Intracavitary site

Intraluminal site

Superficial seat

Vascular site

Uterus
Uterine cervix
Vagina

Trachea
Esophagus

Skin

Blood vessels

Figure: the seeds with which brachytherapy is performed. Similar to rice grains, they are "loaded" with radioactive material and then inserted into the tissue affected by the tumor. From the site: http://en.wikipedia.org/

Table: the various forms of contact brachytherapy are reported (intracavitary, intraluminal, superficial and vascular) and at least one example of tumor site for each of them.

THE DOSE OF RADIOACTIVITY €: HIGH OR LOW DOSE BRACHITHERAPY

Based on the dose of radioisotopes released from the sources, brachytherapy can be distinguished into high-dose radioactivity brachytherapy and low-dose radioactivity brachytherapy. Here are the implications of each procedure:

• High-dose radioactivity brachytherapy. In these cases, the placement of very powerful radioactive sources is envisaged, so much so that the treatment lasts a few minutes (no more than 20) and is repeated no more than twice a day, for a few days or weeks. There is no real hospitalization of the patient, but his isolation (in a special room in the treatment center) as long as the exposure to the radioactive material. At the end of the treatment, the radioactive source is removed and the patient can leave the hospital. hospital and go back to your daily activities.
  Precautions, during the treatment period: it is important that the patient does not come into contact with anyone (except adequately protected medical personnel), due to the risk of radiation contamination.
  Pain or discomfort during the treatment period: high-dose brachytherapy does not usually cause pain; in addition, the isolation room is equipped with all comforts. Any inconvenience may arise when the sources are inserted.
• Low-dose radioactivity brachytherapy. We have recourse to the insertion of little powerful sources and a long exposure is foreseen for many hours, if not even days. Obviously, the patient must be hospitalized and kept as isolated as possible, despite the low radioactivity. There are rooms equipped with all comforts, in which the patient can feel at ease.
  Once the therapy is complete, the radioactive material is removed and the patient can return to his daily activities.
  Precautions, during the treatment period: visits to the patient by family members must be reduced to essentials. Furthermore, it is good that children and pregnant women avoid making contact with individuals under treatment.
  Pain or discomfort during the treatment period: in general, low-dose brachytherapy does not cause pain, and if these should arise, the medical staff is still ready to intervene. Some discomfort may appear due to forced isolation or at the time of insertion of the radioactive material.

DURATION OF TREATMENT: PERMANENT OR TEMPORARY

Premise: the radioactive materials, used for brachytherapy, are not eternal, but undergo the so-called phenomenon of radioactive decay, or the progressive loss of radioactive capacity. This process lasts a few weeks and, once finished, the supports (seeds, cylinders, etc.) are "empty" and devoid of any effect.

Radioactive sources can be left in place permanently or removed and replaced at regular intervals. In the first case, we speak of permanent brachytherapy, while, in the second, of temporary brachytherapy. In detail:

• Permanent brachytherapy. This method involves the insertion of seeds with very low radioactivity, which, once properly arranged, are left in place even after their decay. These sources, in fact, are in no way harmful to the patient. The dose of material radioactive is so low that the treated individual poses no danger to the people around him on a daily basis.
  Precautions, during the treatment period: although the risk of spreading harmful radiation is very low, the patient is advised to have close contact with children and pregnant women. This restriction lasts a few weeks or a few months, depending on when the radioactive charge of the source ends.
  Pain or discomfort during the treatment period: In some areas of the body, the insertion of the seeds can be painful. However, once placed in place, the pain ceases and the patient usually does not feel any particular ailment.
• Temporary brachytherapy. This therapeutic protocol provides for the placement, replacement (once decay has taken place) and definitive removal of the radioactive sources. The dose of radioactivity can be low or high, depending on the tumor being treated. The duration of the treatment ranges from a few hours to a maximum of 24 hours, depending on the radioactive power of the sources. Patient isolation is required at the time of treatment.
  Precautions, during the treatment period: are the same as those described for high-dose and low-dose radioactivity brachytherapies.
  Pain or discomfort during the treatment period: insertion could be painful.

The results

The results and efficacy of brachytherapy, as is the case with many other anticancer therapies, represent an unknown factor. Each patient, in fact, responds to treatments in a different way and this depends exclusively on the characteristics of the tumor, that is, if it is severe, infiltrated, benign, malignant, slow-growing, etc.
In any case, to understand if there have been any benefits after brachytherapy, it is necessary to perform diagnostic tests, such as CT and MRI.