Latest generation lineal accelerator for radiotherapy

The Cancer Department at the la University of Navarra University Hospital has acquired a Siemens, latest-generation lineal accelerator. This is the first centre in Spain to install this advanced radiotherapy apparatus which is equipped with multilaminas, minimultilaminas and portal vision.

The new radiotherapy equipment has the Moduleaf system as an extra feature minilaminas of 2.5 mm – the thinnest that currently exists in this technology – that can shape irregular parts of tumours with much greater precision. To date laminas of 1 cm have been used, in which the dosimetric yield is less precise in the case of small lesions. The new system enables the application of very exact and precisely-adapted treatment such as radiosurgery, radiotherapy stereotactics or radiotherapy with modulated intensity.

Modulated intensity

A lineal accelerator is a device that enables the treatment of malignant tumours by means of the emission of radiations. At present, the equipment shapes or moulds the radiation field through a system of multilaminas that are indispensable in order to carry out this shaping of the radiation beam. This beam modulation enables the adaptation of the radiation dose to the anatomy of the desired volumes of tissue, whereby the radiation of healthy organs is diminished at the same time as that of affected tissue increased. With the minimultilaminas we can modulate the beam intensity at smaller volumes of tissue, thus enabling a greater number of appplications.

Uses

The latest-generation lineal accelerator installed at the University Hospital, apart from treating any kind of tumorous zone, is especially useful for the treatment of brain tumours that are small and of irregular shape, both benign and malignant, as well as cerebral functional pathology. This is why they are studying putting into operation a protocol for the treatment of certain cerebral functional lesions, such as certain cases of epilepsy. Moreover, it is seen as a therapeutic alternative to selected lung cancers, spinal tumours close to spinal cord, tumours at the base of the cranium and as consolidation of oligometastasis at the level of the liver, retroperitoneum, lung, etc.

Moreover, the new accelerator is capable, by means of its portal vision, of comparing with precision the radiation field in real time with the computer-designed one and, in this way, in situ corrections for deviations in the positioning of the patient can be carried out or, as the case may be, for the movements in the organ itself where the tumour, which can vary from day to day and, finally, for changes in the size of the tumour as a response to the treatment.

This is what is known as image-guided radiotherapy (IGRT) or adapted radiotherapy.

Finally, it enables the carrying out of conventional treatment – tridimensional and modulated radiotherapy with conventional laminas, thus being complementary to the rest of the cutting edge technology equipment in the cancer department.