New technique in permanent bradytherapy for the treatment of lung cancer

The University Hospital at Navarre University has developed a system for the percutaneous implantation of palladium 103 seeds, a new technique in permanent bradytherapy for the treatment of lung cancer. Recently, the fourth experiment was carried out and the results remitted to the scientific magazine, “Bradytherapy”, for its publication. To date there has been no description in world scientific literature of any case using this therapeutic procedure.

The Clínica Universitaria has hosted the only cases of bradytherapy using palladium implantation although, in the literature, there exist two articles on the treatment of 8 patients with iodine 125, a radioisotope especially suited to treatment of prostate cancer. In this case it was decided to opt for palladium 103 given that theoretically it adapts better to rapid and aggressive growth lesions such as the majority of primary lung tumours – although this affirmation is not backed up by clinical data. Apart from this, the isotope having a shorter half-life, the radiological protection measures are reduced.

Bradytherapy is a radical radiation technique which is undertaken jointly by the Radiology and Oncology Departments at the University Hospital. It involves the percutaneous implantation of radioactive seeds by means of vectors that are placed inside the tumour. The procedure is carried out under a general anaesthetic with the patient lying on their back. First, the radiologist selects the target area and then the vectors are introduced with the point guided by CAT (computer-controlled axial tomography); in this way the structures through which they pass can be seen in practically real time. Once it is confirmed that the vectors are correctly placed into position, the radioactive load is impanted.

Suitability

Bradytherapy with palladium 103 is suitable for those persons with small lesions which, because they are deemed medically unsuitable (because of age, accompanying illnesses, limited pulmonary capacity, etc.), cannot be subjected to open surgery involving the resection of lung tissue. They are very select, high-risk patients who have tumours accessible at the point of puncture by an external route. Until now, the only alternative therapy available to these patients has been external radiation. Nevertheless, this treatment has the drawback of lasting possibly weeks, whereas Bradytherapy is carried out in just one day.

The results obtained with this technique are very satisfactory although not definitive, given the short period of monitoring. Apart from these data, in the opinion of Dr. Martínez-Monge, Bradytherapy has demonstrated its success as a therapeutic option for this group of patients who cannot undergo surgery.

Given that the implantation of palladium 103 is carried out in a percutaneous manner, this technique provides the advantage of a rapid recovery without pain. Moreover, the only two possible complications (pneumothorax, i.e. entry of air into the thoracic cavity and the risk of bleeding) are verified in situ, which allows a rapid response. In any case, none of the patients treated with this procedure has shown these complications nor have others been observed.