Dosimetría tridimensional por Monte Carlo del tratamiento tópico con 188Re de carcinoma de células escamosas y células básales

Dosimetría del tratamiento tópico de cancer con Re-188

Abstract

Basal and squamous cell carcinoma is currently treated mainly by surgery. In search of non-invasive treatments, the topical treatment with ¹⁸⁸Re was developed, which has shown satisfactory therapeutic results. However, there are currently only two-dimensional descriptions of the absorbed dose distribution in the target region, which limits the information regarding to the absorbed dose (D) imparted to surrounding healthy tissue. Methodology. The simulation scenario was a cream containing a uniformly distributed 188Re, a mylar plastic sheet, and a voxel type phantom representing the skin with a volume of ​​2X2X0.1 cm3 and a voxel size of 100 µm per side. The isodose surfaces, as well as the curves in the sagittal and transverse sections, were analyzed to describe the dose distribution. Results and Conclusion. The Homogeneity Index reveals how homogeneity decreases as depth increases. Tables are reported with the irradiation time necessary to deliver a 50 Gy radiation dose in a 250-750 µm depth range. With the therapeutic configuration described in this work, which is the one used in clinical practice, it was found that it is possible to give a treatment to a depth of 250-650 µm without exceeding the limit of absorbed dose recommended for the epidermis, which is exceeded if the prescribed radiation dose is reached at a depth of 750 µm.