Patient-specific nuclear medicine treatment planning with Monte Carlo techniques

P. PÉREZ; F. MALANO; M. VALENTE

Montevideo

Congreso; 2da Reunión Reunión Conjunta SUF-AFA 2011; 2011

Sociedad Uruguaya de Física - Asociación Física Argentina

Different radionuclides have proved to be appropieated for radioinmunotherapy. Dosimetric performance of each radionuclide has to be carefully studied and characterized before any treatment. These studies can help to optimize both the damage to the tumor to be irradiated and minimize the probability of complications in sensitiveorgans close to the tumor. It would be desirable to introduce patient specific images during the planning and calculations process inorder to improve and optimize dosimetric performance. In this sense, both the tumor activity and the patient anatomy should be incorporated. Metabolic imaging techniques have shown to be valuable non-invasive and reliable diagnostic methodologies. Besides, X-Ray computed tomography can be used to generate 3D-images with information about patient anatomical structures. Nowadays, dual imaging techniques like PET-CT or SPECTCT are capable to suitably combine both functional and anatomical imaging methods even assessing accurate matching between them. This work presents a method capable of performing dose distribution for nuclear medicine dosimetry by means of Monte Carlo methods using specific-patient images in order to assess 3D-dose calculation aimed to treatment planning. The developed calculation system allows to perform simulation concerning different types of radionuclides including  , + and − isotopes. The 3D-dose distribution is achieved by means of suitable voxelization methods. The feasibility, reliability and accuracy of the developed method has been carefully investigated by means of comparisons with alternative dosimetric systems. As example, scaled dose point kernels (sDPK) have been considered for preliminary validation. The obtained results suggests a promising performance.