RESUMEN
Objetivos: se evaluó si la técnica de prescripción de dosis puntual, punto "A", es adecuada para la estimación de dosis en el volumen de tratamiento clínico por alta tasa de dosis (CTV-HR), usando la braquiterapia ginecológica 3D. Métodos: se recopiló planes de tratamiento para 35 pacientes con cáncer cervicouterino estadio IB2-IVA (140 fracciones o planes de tratamiento) tratados entre los años 2019 al 2021, cuya dosis prescrita fue de 28 Gy en 4 fracciones. Se reconstruyeron los puntos "A", se normalizó la dosis prescrita a la isodosis del 100% para comparar con las dosis en CTV-HR (D90%). Resultados: el promedio de la dosis absorbida al CTV- HR (D90%) fue de 88,82 ± 2,53 Gy y al normalizar la isodosis del 100% al punto "A", se obtuvo dosis promedio en CTV-HR (D90%) de 99,3±5,85Gy. Esta variación de dosis promedio al CTV-HR (D90%) representó un incremento del 18%, dando como resultado que un 80% de los tratamientos correspondiente a 28 pacientes queden fuera de la variación aceptable del protocolo EMBRACE II y solo un 20% de los tratamientos correspondientes a 7 pacientes se encuentren dentro del rango de la variación aceptable del protocolo en mención. Conclusiones: la técnica de prescripción de dosis al punto "A", se traduce clínicamente en una sobredosis del tejido tumoral y sano (recto, sigmoide, vejiga e intestino).
Objective: to assess whether the punctual dose prescription technique, point A, is adequate for dose estimation in CTV-HR using 3D gynecological brachytherapy. Methods: treatment plans were collected for 35 patients with stage IB2-IVA (140 fractions or treatment plans) cervical cancer treated between 2019 and 2021, whose prescribed dose was 28Gy in 4 fractions. Points A were reconstructed, the prescribed dose was normalized to 100% isodose to compare with the doses in CTV- HR(D90%). Results: the average dose absorbed at CTV-HR(D90%) was 88.82 ±2.53 Gy and when normalizing the isodose of 100% at point A, average dose at CTV-HR(D90%) was obtained. of 99.3±5.85Gy. This average dose variation to the CTV-HR(D90%) represented an increase of 18%, resulting in 80% of the treatments corresponding to 28 patients falling outside the acceptable variation of the EMBRACE II protocol and only 20% of the treatments corresponding to 7 patients are within the range of the acceptable variation of the protocol in question. Conclusions: the dose prescription technique at point A clinically translates into an overdose of tumor and healthy tissue (rectum, sigmoid, bladder and intestine).
RESUMEN
The sustainable use of marine resources is a competitive advantage of the most developed countries, which has a positiveimpact on the economic and social development of their populations. Currently, marine organisms such as macroalgaeare an important source of functional compounds such as polysaccharides, proteins, unsaturated and polyunsaturatedfatty acids, among others, with nutritional value and pharmacological properties. Gracilariopsis tenuifrons is amacroalga found in the Colombian Caribbean Sea, which has been neither chemically nor physicochemically studied;therefore, the aim of this study was to evaluate the polysaccharides composition and nutrients contents of crudeextract and its UV radiation absorption capacity. The purification was carried out by ultrafiltration using membranesof molecular size exclusion 100, 50, 10, and 3 kDa. The chemical characterization was done by gel electrophoresis,Nuclear Magnetic Resonance, Fourier Transform Infrared Spectroscopy, and the particle size and potential zeta byDynamic Light Scattering. The absorption coefficient (absorbance/g dry sample) was measured at 290, 310, 340, and380 nm. Sulfated and non-sulfated polysaccharides were detected in the fractions and identified as polysaccharidestype k, and β-carrageenan and alginate. The proximate analysis showed that the total content of protein, carbohydrates,fat, and calories is 15.58%, 69.81%, 0.15%, and 342.94% Kcal, respectively. The crude extracts showed an importantabsorption coefficient in UVB-UVA range. The findings suggest that G. tenuifrons seaweed propagated in vitro is aviable candidate of natural additives, such as phycocolloids and bioactive compounds, for designing new functionalproducts in the pharmaceutical and cosmetic industry, in addition to its nutritional properties to be used in foods.