RADT-24. SYNTHETIC TREATMENT OF CENTRAL NERVOUS SYSTEM EWING/PRIMITIVE NEUROECTODERMAL TUMOR (EWING/PNET): A CASE REPORT

Ewing/PNET is a rare tumor of the central nervous system. After the standard treatment, there’re still 86.7% of patients had recurrence and no standard treatment after recurrence. Here we report a case of Ewing/PNET with a good survival after synthetic treatment to provide evidence for future clinical strategies. A 23-year-old male underwent resection of the left frontal tumor on April 28, 2017, the pathological diagnosis was Ewing/PNET. He received whole brain radiotherapy 36Gy in 18 fractions, and tumor bed boost to 56Gy in 28 fractions, with 3 courses of Nedaplatin adjuvant chemotherapy. The tumor recured 23 months after the surgery. The patient underwent the second resection, followed by 4 courses of ADM+VCR+CTX/IE chemotherapy. However, 27 months after the first surgery, the tumor evaluation progressive resection of recurrent tumors in the anterior cranial base-ethmoid sinus. During the chemotherapy, MRI showed that tumor still increased. There was a mass in the root of the forehead and nose. After the third recurrence, the patient received re-radiotherapy (50Gy in 25 fractions) 29 months later after the first RT. The tumor was significantly reduced after radiotherapy. Physical examination showed that the sense of smell continued to weaken, the visual acuity was the same as before. 8 courses of VIT (Irinotecan, vincristine, temozolomide) were followed by second RT, tumor was assessed every 2 courses. 44 months after the first surgery, he suffered a third recurrence in spina cord. And then he received rescue RT (20Gy in 10 fractions) in the recurrent tumor. The tumor was reduced after local radiotherapy. He was undergoing follow-up till May 2021, And the OS is 49 months. In conclusion, the incidence of this disease is low, especially in adults. However, the prognosis is poor. Early detection, early operation, combined with radiotherapy and chemotherapy are promising to improve the efficacy of Ewing/PNET.