LOGX

Low Energy Gamma and X-ray therapy

 Partecipanti

Mappa

 Word cloud

Esplora la "nuvola delle parole (Word Cloud) per avere un'idea di massima del progetto.

 Obiettivo del progetto (Objective)

'Cancer is a serious disease with high mortality and morbidity. Treatment is often performed with radiation therapy. To assure a good control of the tumour with limited side effect, a very high conformity of the radiation field is needed in the treatments. This led to the development of very complex treatments using external photon beam. There is however another, more cost-effective, way to achieve that very high conformity. For localized tumours, this can be done by inserting radioactive photon sources emitting x-rays or gamma rays, directly inside the tumour. This technique is called brachytherapy and is the focus of this proposal. Because of advantages for dosimetry and radioprotection, all the latest developments in brachytherapy source design are pointing in the direction of the reduction of the photon energy. This presents dosimetric difficulties caused for example by the increase of the importance of tissue composition. The present standard for brachytherapy considers the patient as a 30cm diameter water sphere. Another question concerns the radiobiological effectiveness (RBE) of low energy photons. Although low energy photons have been suspected to have a RBE different than the higher energy photons there are not many studies about the subject and it is not taken into account clinically. This project proposes to study the physics of low energy photons used in brachytherapy and to assess the influence of the patient geometry and composition on the dosimetry and to determine the radiation quality taking into account the non-water equivalence of tissue for low energy sources by performing physical measurements and Monte Carlo calculations. We will develop a fast and accurate way to individualize and optimize the treatment including the RBE effect. Drastically improving the dosimetry for those low energy sources is of utmost importance to bring brachytherapy at the same level of accuracy than what is currently achievable for external beam radiotherapy.'

Introduzione (Teaser)

Recent advances in radiation oncology place the radiation source inside the tissue to be treated. A new tool treating the human body as a complex geometry and not a ball of water will ensure accurate dosing and assessment of biological effectiveness.

Descrizione progetto (Article)

Radiation has been successfully used to treat cancerous tumours for over 100 years. Despite many advances and new therapies, it remains one of the three main pillars of oncology along with surgery and chemotherapy. Brachytherapy based on internally sourced radiation has become a promising alternative to more conventional external-beam forms of radiation in some cases. It is a more cost-effective and highly localised way of delivering radiation by inserting radioactive sources of gamma rays or X-rays directly into the tumour.

Advances in brachytherapy source design are moving toward reductions in photon energy. The EU-funded project 'Low energy gamma and X-ray therapy' (LOGX) was designed to update current human models used for dosimetric studies and investigate the effects of those changes on radiation quality. Previous studies modelled the human body as a sphere of 30-cm diameter filled with water and investigated high-energy photons. LOGX has contributed knowledge critically needed to bring the accuracy of brachytherapy up to speed with that achievable for external beam therapy through its evaluation of low-energy photons in full patient geometry.

Scientists began by filling in background knowledge, obtaining accurate dosimetry and microdosimetry in the area around low-energy photon sources in human tissue. Following simplifying approximations and optimisation of algorithms for speed, this data was used to create a tool for clinical application. It enables the user to modulate the photon energy. In the final phase, the fast algorithm was combined with data from the dosimetry studies. The end result is a tool for assessing the effects of the brachytherapy both from a dosimetric standpoint and that of its radiobiological effectiveness for full patient geometry.

LOGX outcomes were used to inform a recent report by the American Association of Physicists in Medicine (AAPM) regarding algorithms for dose calculation in brachytherapy. The high visibility worldwide supports a competitive position for the EU in radiation oncology. Further, and more importantly, results will improve dose calculation for brachytherapy and enable better quality of life for millions of EU citizens.