Prediction of phosphenes occurrence in patients undergoing photon irradiation to ocular structures due to brain tumor.

BACKGROUND AND OBJECTIVE: Phosphenes are visual light phenomena that are experienced when there is no apparent light that stimulates the eye. In oncology, phosphenes are also present during radiation therapy for patients with tumors of the central nervous system, eyes, head and neck. Due to the discomfort of patients treated with irradiation to the head regions, research is conducted to determine whether the dose to the ocular structures is predictive for the occurrence of phosphenes. The objective was to demonstrate the relationship between the doses of the retina and vitreous humour with the appearance of phosphenes. MATERIAL AND METHOD: A descriptive study was carried out in a prospective cohort in 25 patients older than 18 years, with malignant tumours located at the level of the brain, both of primary and secondary origin, subjected to irradiation in 6 MV linear accelerators, during February 2020 to January 2021. As independent variables: Retinal dose and vitreous humour dose, and as dependent variables: Light flashes and stable light. Logistic regression analysis was used for prediction, using the SPSS statistical program (version 26.0). RESULT: A final date of 380 external radiotherapy treatments. The presence of any of the events in a prevalence of 58.7% of the total of fractions. The distribution for the presence of both events, flash of light and stable light, was 69.1%, 20.6% and 10.3% respectively. In the logistic regression analysis, for the light flare, only the dose factor in vitreous was significant (OR: 1.74, IC [1.059-2.419] p: 0.001). For stable light, the dose in the retina (OR: 1.73, IC [1.121-2.341] p: 0.005), and dose in the vitreous humor (OR: 1.82, IC [1.335-2.315] p: 0.003). CONCLUSIONS: There is a predictive relationship between the doses of irradiation of the retina and vitreous humour, for the generation of phosphenes. These results help radiotherapy centres take these anatomical structures into account to reduce the presence of phosphenes in patients. Likewise, it would help to reduce phosphenes, keeping the bunker area illuminated during the treatment.

Predicción de ocurrencia de fosfenos en pacientes sometidos a irradiación con fotones a estructuras oculares por tumor cerebral / Prediction of phosphenes occurrence in patients undergoing photon irradiation to ocular structures due to brain tumor

Antecedentes y objetivo Los fosfenos son fenómenos de luz visual que se experimentan cuando no hay luz aparente que estimule el ojo. En oncología, los fosfenos también están presentes durante la radioterapia para pacientes con tumores del sistema nervioso central, ojos, cabeza y cuello. Debido a la incomodidad de los pacientes tratados con irradiación en las regiones de la cabeza, se realiza investigación para determinar si la dosis en las estructuras oculares son predicción para la ocurrencia de fosfenos. El objetivo fue demostrar la relación entre las dosis de retina y humor vítreo con la aparición de fosfenos. Material y método Se realizó un estudio descriptivo, en una cohorte prospectiva en 25 pacientes mayores de 18 años, con tumores malignos localizados a nivel de encéfalo, tanto de origen primario como secundario, sometidos a irradiación en aceleradores lineales de 6MV, durante febrero 2020 a enero del 2021. Como variables independientes: dosis a retina y dosis a humor vítreo, y como variables dependientes: destellos de luz y luz estable. Para la predicción se utilizó el análisis de regresión logística, mediante el programa estadístico SPSS® versión 26.0. Resultado Una data final de 380 tratamientos de radioterapia externa. La presencia de cualquiera de los eventos en un predominio del 58,7% del total de fracciones. La distribución por la presencia de ambos eventos, destello de luz y luz estable, fue del 69,1, 20,6 y 10,3%, respectivamente. En el análisis de regresión logística, para el destello de luz, solo fue significativo el factor de dosis en vítreo (OR: 1,74; IC 95%: 1,059-2,419; p: 0,001). Para la luz estable, fueron significativos la dosis en retina (OR: 1,73; IC 95%: 1,121-2,341; p: 0,005) y dosis en humor vítreo (OR: 1,82; IC 95%: 1,335-2,315; p: 0,003). Conclusiones Existe una relación predictiva entre las dosis de irradiación de la retina y del humor vítreo, para la generación de fosfenos (AU)

Background and objective Phosphenes are visual light phenomena that are experienced when there is no apparent light that stimulates the eye. In oncology, phosphenes are also present during radiation therapy for patients with tumors of the central nervous system, eyes, head and neck. Due to the discomfort of patients treated with irradiation to the head regions, research is conducted to determine whether the dose to the ocular structures is predictive for the occurrence of phosphenes. The objective was to demonstrate the relationship between the doses of the retina and vitreous humor with the appearance of phosphenes. Material and method A descriptive study was carried out in a prospective cohort in 25 patients older than 18 years, with malignant tumors located at the level of the brain, both of primary and secondary origin, subjected to irradiation in 6MV linear accelerators, during February 2020 to January 2021. As independent variables: Retinal dose and vitreous humor dose, and as dependent variables: Light flashes and stable light. Logistic regression analysis was used for prediction, using the SPSS statistical program (version 26.0). Result A final date of 380 external radiotherapy treatments. The presence of any of the events in a prevalence of 58.7% of the total of fractions. The distribution for the presence of both events, flash of light and stable light, was 69.1%, 20.6% and 10.3% respectively. In the logistic regression analysis, for the light flare, only the dose factor in vitreous was significant (OR: 1.74; 95% CI: 1.059-2.419; p: 0.001). For stable light, the dose in the retina (OR: 1.73; 95% CI: 1.121-2.341; p: 0.005), and dose in the vitreous humor (OR: 1.82; 95% CI: 1.335-2.315; p: 0.003). Conclusions There is a predictive relationship between the doses of irradiation of the retina and vitreous humor, for the generation of phosphenes (AU)

Carcinoma adenoide quístico de cuello uterino: una rara entidad / Adenoid cystic carcinoma of uterine cervix: A rare entity

El carcinoma adenoide quístico es una enfermedad muy rara, representando menos del 1% de todos los carcinomas, con alto riesgo de recurrencia local y a distancia. Aunque no disponemos de una conducta terapéutica estándar hasta la fecha, sin embargo, se cuenta con reportes de ser radiosensible. Se presenta el caso de una mujer peruana de 76 años portadora de carcinoma adenoide quístico de cérvix estadio clínico i, manejada inicialmente con histerectomía radical con resultado patológico de carcinoma adenoide quístico asociado a carcinoma adenoide basal, que presentó recurrencia a distancia tempranamente.(AU)

Adenoid cystic carcinoma is a very rare pathology, representing less than 1% of all carcinomas, and has a high risk of local and distant recurrence. Although there is currently no standard management, there are reports of them being radiosensitive. The case is presented of a 76-year-old Peruvian woman with a clinical stage i cervical adenoid cystic carcinoma, specifically managed with radical hysterectomy with a histological result of an adenoid cystic carcinoma associated with basal adenoid carcinoma, presenting with an early distant recurrence.(AU)