RESUMEN
PURPOSE: To assess the possibility of delivering a homogeneous irradiation with respect to maximal tolerated dose to the optic pathway for paranasal sinus (PNS) tumors. METHODS: Treatment planning with conformal three-dimensional (3D) and conventional two-dimensional (2D) was done on CT scans of 20 patients who had early or advanced PNS tumors. Four cases had been previously irradiated. Dose-volume histograms (DVH) for the planning target volume (PTV) and the visual pathway including globes, chiasma and optic nerves were compared between the 2 treatment plannings. RESULTS: The area under curve (AUC) in the DVH of the globes on the same side and contralateral side of tumor involvement was significantly higher in 2D planning (p <0.05), which caused higher integral dose to both globes. Also, the AUC in the DVH of chiasma was higher in 2D treatment planning (p=0.002). The integral dose to the contralateral optic nerve was significantly lower with 3D planning (p=0.007), but there was no significant difference for the optic nerve which was on the same side of tumor involvement (p >0.05). The AUC in the DVH of PTV was not significant (201.1 + or - 16.23 mm(3) in 2D planning vs. 201.15 + or - 15.09 mm(3) in 3D planning). The volume of PTV which received 90% of the prescribed dose was 96.9 + or - 4.41 cm(3) in 2D planning and 97.2 + or - 2.61 cm(3) in 3D planning (p >0.05). CONCLUSION: 3D conformal radiotherapy (RT) for PNS tumors enables the delivery of radiation to the tumor with respect to critical organs with a lower toxicity to the optic pathway.
Asunto(s)
Neoplasias de los Senos Paranasales/radioterapia , Radioterapia Conformacional , Adolescente , Adulto , Anciano , Área Bajo la Curva , Femenino , Humanos , Masculino , Persona de Mediana Edad , Quiasma Óptico/efectos de la radiación , Nervio Óptico/efectos de la radiación , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Conformacional/efectos adversos , Estudios RetrospectivosRESUMEN
We evaluated the efficacy of benzydamine oral rinse for prevention of radiation-induced mucositis. Patients with head and neck cancers, who were referred in 2004-2005, received an oral rinse of either benzydamine or placebo. One hundred patients were randomized in this trial. At the end of the study, 19 patients were excluded from the analysis because they did not use the medication for the assigned period. In the benzydamine group, the frequency of mucositis grade > or =3 was 43.6% in contrast to 78.6% in other group (P = 0.001). Grade > or =3 mucositis was 2.6 times more frequent in the placebo group. Intensity of mucositis increased up to fourth week of treatment in both groups to grade 2. In the treated group the grade of mucositis was approximately constant to the end of therapy; but in the control group it raised to grade 3 (P < 0.001). The highest grade of mucositis during the treatment time was significantly different between two groups (P = 0.049). The median interval to observation of grade > or =2 mucositis was 24 days in the placebo group and 28 days in the benzydamine group (P = 0.12). Benzydamine oral rinse seems to be effective, safe, and well tolerated for prophylactic treatment of radiation-induced oral mucositis in head and neck tumours.