¿Dosis menores de Radioterapia generan mayor riesgo de Fístulas Vaginales en pacientes con Cáncer de Cuello Uterino?

The treatment of cervical cancer with ionizing radiation and radiosensitizing chemotherapy can have as a complication the generation of vaginal fistulas. The aim of the present study was to establish the prevalence of vaginal fistulas in a group of patients who received conventional radiotherapy versus 3D radiotherapy. Methods: The present retrospective study was carried out at the Solon Espinosa Ayala Hospital, SOLCA-Quito. The patients who received external radiotherapy either in 2D or 3D modality plus brachytherapy or external dose reinforcement, with concurrent chemotherapy or without the latter in the study period January 2008 to December 2012, were registered. For the analysis, radiotherapy types were compared and Odds Ratio is reported. Results: 315 cases were registered in the 2D Conventional Radiotherapy group (R2D) and 299 cases in the Conformacional 3D radiotherapy group (R3D). The prevalence of fistulas in the R2D group was 10 cases (1.62 %) and in the R3D group it was 8 cases (1.31%), Odds ratio 1.19 (95 % CI 0.46 to 3.06) P = 0.71. Of the 18 cases of fistulas, 9 cases (50 %) were externally reinforced, 6 cases (33 %) by brachytherapy and 3 cases (17%) without reinforcement. The external reinforcement vs. brachytherapy showed an OR = 4.77 IC 95 % (1.66 - 13.65) P = 0.04. The dose of radiotherapy used in the Brachytherapy treatment was 87.5 ± 2.5 Gy vs Reinforcement 68 ± 2.5 Gy, P <0.001. Conclusion: There is no difference between the prevalence in the groups of conventional radiotherapy versus 3D radiotherapy. Booster radiotherapy is a risk factor for vaginal fistulas compared to brachytherapy, even when the dose of radiotherapy was lower in this group.