High dosage brachytherapy obtains excellent results in head and neck tumors

These are the conclusions of research undertaken jointly by three Departments at the University of Navarra Hospital and which was published in the latest issue of Brachytherapy, official journal of the American Society of Brachytherapy.

The work describes the application of this new radiotherapy technique to 40 patients between 2000 and 2006. Given the size of the sample, the article is a description of the greatest number of patients treated with high-dosage brachytherapy for head and neck tumours in world medical literature. According to results, after a seven-year follow-up, the illness was controlled in 86% of the cases and the percentage of survival was 52%.

In concrete, the research focused on the treatment of tumours in the oral cavity, those affecting the tongue and the floor of the mouth, and those in the oropharyngeal region, such as tumours of the tonsils.

Involved in the study was a multidisciplinary team of seven specialists from three departments at the University of Navarra Hospital: the Radiotherapy Department, the Department of Oral and Maxillofacial Surgery and the Ear, Nose and Throat Department.

Intensifying radiation dosage

As is known, brachytherapy is a radiotherapy treatment involving the placing of radioactive sources within the tumour or nearby.

In the case in hand, the work analysed the application of brachytherapy as complementary post-surgery treatment, explained Doctor Rafael Martínez-Monge, Director of the Radiotherapy Department. Some cases of head and neck tumours require the application of radiotherapy after the surgical operation. Using this technique, they have managed to intensify the radiation dosage with the goal of reducing relapse rates.

In certain treatments, brachytherapy provides better end-result possibilities than conventional radiotherapy. The procedure enables the administration of doses that would not be easily achieved using other techniques, due to toxic effects, explained the specialist from the University of Navarra Hospital.

Two weeks of treatment less

Moreover, the use in brachytherapy of high dosages involves a series of benefits for the patient as regards the overall treatment. The great advantage, points out Doctor Martínez-Monge, is the reduction of total time. While conventional radiotherapy treatment lasted seven weeks, administering part of the radiation through brachytherapy can take two weeks less.

This technique also manages to reduce the time of radiation compared to treatment with low dosage brachytherapy. Thanks to the existence of new sources of radiation, the treatment is released in a matter of minutes. Before the patient under brachytherapy treatment carried the radioactive source for several days and, thus, had to be isolated in a lead-lined room, with limitations on visits and nursing care. With high-dosage brachytherapy, however, the patient is only radioactive during the actual administration of the treatment; as such, the rest of the time can be spent in a conventional room.

For the administration of this technique it is necessary to prepare the affected region during the surgical operation. On extirpating the tumour, the surgeon covers the surgery zone — the area with greatest possibilities for relapse — with a series of plastic tubes which are subsequently filled with radioactive material, the aim being to effect a highly selective and precise radiation. Brachytherapy is introduced through these tubes, one end of which appears at the surface of the skin, like a drainpipe, explained Doctor Rafael Martínez-Monge. These tubes are connected to a machine that administers the treatment according to a computer programme personalised for each patient, he added.

Application to other types of tumour

Apart from perioperative high-dosage brachytherapy treatment for head and neck tumours, the University of Navarra Hospital has been working on the application of this procedure to other oncological processes for a number of years. There are a number of studies under way on its use in gynaecological tumours and sarcomas, amongst others. Since 2000 about 400 patients, with different types of tumours, have been treated with this technique.