Internal Radiotherapy or Brachytherapy

"The great advantage of brachytherapy is the reduction of the total treatment time. With conventional radiotherapy it lasts about seven weeks. With brachytherapy, five days."


What is brachytherapy?

Internal radiation therapy or brachytherapy represents a special radiation technique that is based on the introduction of a radioactive source (radioisotope) into the tumor or tumor bed (healthy tissue next to the tumor that remains after removal of the tumor and has a high risk of containing residual microscopic disease).

It provides the precision of carrying a source that administers very intense radiation but with a gradient, that is, it intensely irradiates the closest tissue and with less intensity as the tissue is further away from this radiation source. This means that healthy tissues will not have radiation doses.

This technique is applied especially for genitourinary and gynecological tumors and for sarcomas.

The Clinica Universidad de Navarra is one of the international reference centers in the performance of intraoperative implants and radiation treatment with the high-dose rate brachytherapy technique during the post-operative period of different types of tumors.


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Types of internal radiotherapy or brachytherapy

Interstitial brachytherapy introduces the radioactive source into the tumor or tumor bed.

Temporary interstitial implants introduce the radioactive source into the tumor or tumor bed removed by means of special delivery devices, applicators.

There are many types of applicators (catheters, needles, cylinders, tubes, balloon systems, etc.), several of which are specific to each treatment. Their common characteristic is that they are hollow and allow a remotely controlled radioactive source, which releases the radiation, to move inside them.

Temporary interstitial brachytherapy treats various tumors: prostate, gynecological, breast. It is generally used as a complementary technique to external radiation to deliver an extra dose of radiation (overlay or boost) to the tumor or tumor bed.

Temporary interstitial brachytherapy procedures can be performed during tumor removal (open cavity). The same surgery is used to directly recognize the tumor bed (which is a high-risk area for microscopic residual disease) and to cover it with a series of thin plastic tubes (catheters) that are used to apply the radiation treatment during the perioperative period.

The advantages of performing the implant in an open cavity are: minimizing the error of recognition of the risk area and administering in advance a radiation treatment that adjusts the radiation dose according to the distance of the tumor from the resection margins.

The permanent interstitial brachytherapy, known as stereotactic brachytherapy, low rate brachytherapy or more popularly called seed implant, introduces (implants) closed or sealed sources of radioactive material (seeds) of small size (4.5 mm long by 0.8 mm in diameter, in the case of which, lodged in the target volume (tumor or diseased organ), will remain anchored in it indefinitely releasing the radiation in an uninterrupted way until the complete disintegration of the radioactive material takes place.

The permanent implant most frequently performed in the clinical setting is the low rate implant with 125Yodo seeds for prostate tumors.

The Clinic was the first Spanish center to perform intraoperative brachytherapy, which significantly reduces the time of radiotherapy administration.

It consists of the partial irradiation of the tumor thanks to the implantation of catheters in a minimally invasive way, in the same surgical act in which the tumor is removed.

During surgery, 5-10 plastic tubes are placed in the surgical cavity left after the tumor is removed, where there is a risk of remaining microscopic residual tumor disease or where there is a risk of containing microscopic tumor disease not removed by the surgeon. These tubes are attached to the surgical cavity and are removed to the surface just like a surgical drain.

Subsequently, the catheters allow the total necessary radiation to be applied on an outpatient basis over a period of 5 days (2 sessions per day), as opposed to the 6 weeks required in conventional radiotherapy.

Radiation treatment is planned using a three-dimensional navigator that makes it possible to very precisely assign the high dose of radiation to the area that most requires it, thus reducing the radiation to healthy organs such as skin, heart and lungs.

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How is internal radiotherapy performed?

A specially trained team of professionals led by a radiation oncologist participates in the radiotherapy treatment.

The radiation oncologist is a physician specializing in radiation oncology who develops, prescribes and supervises the radiation treatment plan. He can modify the treatment depending on the patient's evolution, identifies and treats the adverse effects of irradiation and collaborates with other specialists involved in the multidisciplinary treatment of cancer such as medical oncologists and surgeons.

Medical physicists work closely with the radiation oncologist in planning and administering treatment. They supervise the work of the dosimetrist and are directly involved in planning complex treatments. In addition, they develop and manage treatment unit quality programs and perform tests to establish the proper functioning of the units and the quality of the radiation beam.

The dosimetrists work together with the radiation oncologist and the medical physicist to select the radiation technique capable of generating the best distribution of the radiation dose over the tumor and the greatest exclusion of radiation doses to healthy tissues. The work is done on computers that use complex calculation algorithms capable of processing different types of images.

The radiotherapy technician is the person in charge of performing the daily radiation treatment supervised by the physician. He or she must be meticulous in the daily immobilization and positioning of the patient, ensure that the proper treatment has been done, and make a daily record of the treatment.

The radiation oncology nurse works with the entire treatment team to address the needs of the patient and family before, during and after treatment. They explain the care to be taken during and after irradiation and possible adverse effects and how to treat them.

Other health professionals involved in the care of these patients include medical nutritionists, physical therapists, dentists, and social workers.

Prior to treatment with radiation therapy, the medical radiation oncologist talks with the patient and explains the benefits and risks of treatment as well as other existing therapeutic possibilities.

Afterwards, the simulation is performed, which consists of taking measurements and drawing references on the skin to facilitate the entry of external radiation beams through the skin in a precise and reproducible way in each of the treatment sessions. The patient is immobilized in a comfortable and reproducible position that will be used daily during the irradiation.

For the immobilization of the patient, different devices are used such as thermoplastic masks, vacuum or catalytic resin mattresses, inclined planes, etc., selecting a certain method of immobilization depending on the tumor location and the required precision of the case.

Under these conditions of immobilization and fixation of the patient, a planning CT scan is performed and the corresponding axial images are acquired. These CT images are sent to a computer for virtual planning of the radiation treatment. In the planning computer, a certain photon energy, the number of radiation fields (usually two to four) and the rotation angles of the accelerator head are chosen.

Several treatment plans are generated and the radiation oncologist selects the plan that presents an optimal radiation dose distribution capable of maximizing the radiation dose to the tumor while minimizing the dose to adjacent normal structures.

Finally, the patient starts the treatment in the same position in which the simulation and planning procedures have been performed, after verifying the radiotherapy fields, which is done by comparing images reconstructed in the virtual planning with real images of the patient himself generated by means of a radiographic plate or digital portal images.

Where do we do it?


The Department of Radiation Oncology of the Clínica
of the Clínica Universidad de Navarra

The Clínica Universidad de Navarra's Department of Radiation Oncology has extensive experience in external and intensity-modulated radiotherapy. In addition, we apply various state-of-the-art medical-surgical techniques available in a few Spanish centers. 

We are one of the international reference centers in the performance of intraoperative implants and radiation treatment with high rate brachytherapy technique during the postoperative period.

We have one of the most extensive experiences worldwide in the treatment of intraoperative brachytherapy of head and neck tumors, soft tissue sarcomas and gynecological tumors.

Treatments we perform

Why at the Clinica?

  • Expert professionals of reference at international level.
  • Greater accessibility for national and international patients.
  • State-of-the-art technology, the most advanced in Spain.
  • The most advanced proton therapy unit in Europe at the Madrid headquarters for the treatment of cancer with protons.

Our team of professionals