2022-07-01 16:35


Conference: Bucharest University Faculty of Physics 2019 Meeting

Section: Biophysics; Medical Physics

The role of imaging based on positron emission tomography (PET) and classical computed tomography (CT) in delineation of target volumes in radiotherapy

Tia POPESCU (1), Cristina PETROIU (2)

1) Faculty of Physics, University of Bucharest, Măgurele, Romania

2) MNT Healthcare Europe SRL


PET/CT, radiotherapy, DVH, volume delineation

In the modern era the increase number of some severe diseases (e.g., cancer) has observed. High rates of cancer diagnosis are observed, as well as appearance of aggressive and inoperable forms of cancer. An essential step in treating this disease is the development of individualized treatments, which are based on combination of high precision imagistic methods (e.g., PET/CT) with the radiotherapy methodes. Likewise, the discoveries made in the field of radiotherapy have led to the necessity of developing the basis of treatment plan and made it possible to move from classical methods of treating cancer, like surgery, to noninvasive ones, like radiotherapy in which the destruction of cancer cells is more accurate. The radiotherapy involves treatment plans in which the target volumes (e.g., GTV, CTV, PTV, OARs) must be precisely outlined, in order to ensure the healthy tissue from being unnecessarily irradiated and to minimize the side effects. The frequent use of the PET/CT method is due to its capacity to provide anatomical and functional data, that can be simultaneously evaluated. The anatomical details provided by Computed Tomography and the functional ones from Positron Emission Tomography, ensure both visualization of cancer cell distribution and the tumor shape and size, and also the metabolic activity levels of tissues. Because of the so-called ‘hot spots’, where the radiotracer accumulates, PET increases the chances of healing and helps the planning of future treatments plans. The PET/CT, which involves the use of fludeoxyglucose as a radiopharmaceutical, turned out to be very efficient in diagnosing many types of cancerous tumors, like pulmonary, head and neck cancers, even from incipient stages when no morphological changes could be detected. The analysis of the radiotherapy plan is based on volume delineation in analysis of dose, by dose-volume histogram, that are supposed to be delivered to the patient.

I would like to thank all those who have provided me with the equipment necessary and with their knowledge in analysing of theoretical and experimental data: Jipa Alexandru and Cristina Petroiu