PO106

Ways of the treatment of non-melanomas skin cancer are still under discussion. Recurrences after different modalities usage are still high. It applies to surgery, external irradiation and brachytherapy. Using brachytherapy, we can achieve very high local doses. Moreover, they can be higher, the lower the volume of irradiation. In this sense, brachytherapy has its own characteristics that greatly distinguish it from other approaches, but there are still many unresolved questions in brachytherapy itself. For example, irradiating the tumor with an application method or with injection applicators into the tumor, how to normalize the dose, adhering to the prescribed restrictions. Purpose The aim of the work was to compare the results of three brachytherapy methods in non melanoma skin cancer. Patients and Methods We work at Microselectron, 30 channels. Planning of the isodose distribution is based on CT scans. 370 patients have been treated since 2012. Essential is the question of how many applicators to use and how to distribute them spatially. We use all available methods - iron needles and flexible applicators for interstitial brachytherapy, as well as application methods with individual masks and individual applicator placement. We use boluses to equalize the dose and the arrangement of applicators in several rows. A change in the location of the applicators changes something in the dose distribution that can be used to improve the distribution. That is, for example, to increase the dose value at the center of the tumor and increase the dose-fall gradient at the edges. When we use the applicator method with an individual mask our doses amounted to 36 Gy, 6 Gy, 6 fractions 5 times per week. The normalization of the dose depends on the tumor size, location and some other parameters. In the case of rigid needles insertion we prescribe 8 Gy twice per week, 4 fractions, total dose is equal to 32 Gy. In the case of intratissue irradiation with flexible applicators the total dose is equal to 42.5 Gy, 5.2 Gy, 8 fractions 5 times per week. Interstitial method is used as a rule in the case of volumetric tumors. Results Using iron needles has several advantages - extraction of needles takes place immediately after the delivery of dose in every fraction. The swelling disappears during one hour after extraction, and wound healing after irradiation happens faster. It is especially significant in treating eyelids. However, all three methods are comparable in results when the dose is properly normalized. Conclusion We came to the conclusion that the choice of the method of irradiation, as well as the normalization of the dose in brachytherapy for non-melanoma skin cancer, depends mainly on the characteristics of the tumor and its location. Ways of the treatment of non-melanomas skin cancer are still under discussion. Recurrences after different modalities usage are still high. It applies to surgery, external irradiation and brachytherapy. Using brachytherapy, we can achieve very high local doses. Moreover, they can be higher, the lower the volume of irradiation. In this sense, brachytherapy has its own characteristics that greatly distinguish it from other approaches, but there are still many unresolved questions in brachytherapy itself. For example, irradiating the tumor with an application method or with injection applicators into the tumor, how to normalize the dose, adhering to the prescribed restrictions. The aim of the work was to compare the results of three brachytherapy methods in non melanoma skin cancer. We work at Microselectron, 30 channels. Planning of the isodose distribution is based on CT scans. 370 patients have been treated since 2012. Essential is the question of how many applicators to use and how to distribute them spatially. We use all available methods - iron needles and flexible applicators for interstitial brachytherapy, as well as application methods with individual masks and individual applicator placement. We use boluses to equalize the dose and the arrangement of applicators in several rows. A change in the location of the applicators changes something in the dose distribution that can be used to improve the distribution. That is, for example, to increase the dose value at the center of the tumor and increase the dose-fall gradient at the edges. When we use the applicator method with an individual mask our doses amounted to 36 Gy, 6 Gy, 6 fractions 5 times per week. The normalization of the dose depends on the tumor size, location and some other parameters. In the case of rigid needles insertion we prescribe 8 Gy twice per week, 4 fractions, total dose is equal to 32 Gy. In the case of intratissue irradiation with flexible applicators the total dose is equal to 42.5 Gy, 5.2 Gy, 8 fractions 5 times per week. Interstitial method is used as a rule in the case of volumetric tumors. Using iron needles has several advantages - extraction of needles takes place immediately after the delivery of dose in every fraction. The swelling disappears during one hour after extraction, and wound healing after irradiation happens faster. It is especially significant in treating eyelids. However, all three methods are comparable in results when the dose is properly normalized. We came to the conclusion that the choice of the method of irradiation, as well as the normalization of the dose in brachytherapy for non-melanoma skin cancer, depends mainly on the characteristics of the tumor and its location.