New dose assessment research for image-guided radiotherapy funded by French National Research Agency (ANR)

Posted on 27 July 2015

The AID-IGRT (Additional Imaging Doses and associated risks in Image-Guided RadioTherapy – Toward an optimized therapeutic approach) project, coordinated by the systems modeling and simulation lab at CEA LIST, has been selected for funding by the French National Research Agency (ANR) under the most recent call for projects.

Image-guided radiotherapy is a crucial weapon in the cancer treatment arsenal. To be effective, image-guided radiotherapy treatments rely on very precise positioning of the tumor targeted and, therefore, of the patient’s body. Patients must undergo multiple X-ray imaging sessions to help achieve the necessary degree of precision. However, the sometimes-daily use of these imaging techniques can lead to additional doses of around 1 Gy or 2 Gy. Currently, these additional doses delivered to patients and the potential medium- to long-term impacts on patient health are poorly estimated and, therefore, not sufficiently addressed. Several learned societies have pointed out the problematic issue of controlling doses in X-ray imaging, recommending extreme caution for patients in at-risk groups such as children and young adults. In radiation oncology there is currently no tool clinicians can use to monitor doses during treatment, mainly because such monitoring is not required by law.

This 36-month project will develop an integrated dose-management approach for X-ray imaging in image-guided radiotherapy, with the ultimate goal of making these treatments safer and more effective. The project will address dose management at all stages. First, dosimetric protocols will be established to obtain accurate measurements of doses absorbed by the organs; dosimeters calibrated on anthropomorphic phantoms representing standard patient morphology will be used for these measurements. Software built on Monte Carlo code Penelope will then be developed and validated by comparison with measurements. The software will be used to obtain an accurate estimate of the doses delivered by the main X-ray imaging systems currently used in image-guided radiology treatments, for each organ, for each patient, and for each imaging protocol the patient undergoes. Finally, in image-guided radiology, dose management also involves developing dose optimization strategies, which include incorporating X-ray imaging doses in the treatment protocol. These strategies will be investigated during the research project.

The software—the first ever for this generation of treatments—will be developed by LM2S in conjunction with Dosisoft, a small company that develops software for radiotherapy. Next, the software will be implemented and tested by healthcare professionals like medical physicists and physicians at the four treatment centers in France engaged in this project: CLCC (Centre de lutte contre le cancer) René Gauducheau in Nantes; CLCC Jean Perrin in Clermont-Ferrand; CLCC Eugène Marquis in Rennes; and Assistance Publique des Hôpitaux de Marseille in Marseille.