CEREBRAL RADIONECROSIS IN PATIENTS IRRADIATED FOR CAVUM CANCER: RETROSPECTIVE STUDY OF 15 CASES

Introduction: Cerebral radionecrosis is a rare but a serious complication induced by radiotherapy of the nasopharyngeal cancer. Since nasopharyngeal cancer is common to have skull base infiltration, radiation fields cover inevitably the temporal lobes despite the use of the more advanced intensity-modulated radiotherapy (IMRT). Even though the development of imaging means and the systematic practice of CT and MRI in post-therapeutic monitoring, the diagnosis and treatment of cerebral remain challenging. Materiel and Method:A retrospective study including fifteen cases of cerebral radionecrosis occurring after radiotherapy of cavum cancer, based on data from 382 irradiated for cavum cancer during the period from January 2017 to January 2022 and who were regularly followed in post-therapeutic monitoring. Results: The incidence of cerebral radionecrosis in our patients was 3,9%. The average age of patients was 47.5 years (range 28 - 62 years), with a female predominance (sex ratio: 4M/11F = 0.36). All our patients were followed for locally advanced UCNT of the cavum (73% stage IVA and 27 % stage III). 80% of cases have benefited from conformal radiotherapy technique by intensity modulation (VMAT archtherapy). And all cases have had concomitant chemotherapy. Cerebral radionecrosis occurred after an average delay of 31.6 months (11-77 months) from the end of irradiation. The location of the cerebral radionecrosis lesions was temporal in all our patients. Exploring dosimetric data of our patients, we noted that in 58% of cases the dose constraint at the level of the temporal lobe affected by radionecrosis was not respected. Cerebral radionecrosis was initially discovered on MRI of the cavum, a brain MRI was subsequently requested to show areas of cerebral radionecrosis. Spectroscopy was carried out in 33% of patients. Cerebral radionecrosis was treated with corticosteroid therapy in 53% of cases. After a mean follow-up of 19.8 months (2-63 months) the evolution of cerebral radionecrosis in patients irradiated fornasopharyngeal cancer, was marked by radiological stability without the appearance of clinical symptoms in 53% of cases. Conclusion: Cerebral radionecrosis of radiation-treated cavum patients could be a devastating complication. Furthermore, the differential diagnosis remains challenging and may require the use of advanced imaging modalities. The intricate relationship between dose parameters and radionecrosis incidence requires large-scale longitudinal studies. Despite the fact that there is no definitive treatment for cerebral radionecrosis, bevacizumab has proven to be an encouraging treatment option.