LINC-33. MULTIMODALITY MANAGEMENT OF PAEDIATRIC PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA- UPDATED EXPERIENCE FROM A REGIONAL CANCER CENTRE IN NORTH INDIA

Paediatric primary central nervous system lymphoma(PCNSL) constitutes 1% of all PCNSLs. Data pertaining to paediatric PCNSL (2016–19) was abstracted by retrospective chart review. We identified 7 paediatric patients with PCNSL. None had congenital or acquired immunodeficiency. The median age at presentation was 13 years. The male to female ratio was 4:3. The median ECOG performance status was 2. On neuro-imaging, 3 patients had solitary and 4 patients had multiple lesions. CSF cytology showed atypical cells in 1 patient. None had ocular involvement. Systemic lymphoma work-up was negative in all. Biopsy and resection of tumour were done in 4 patients each. Histopathology revealed DLBCL in 6 and B-cell NHL in 1 patient. All patients underwent induction chemotherapy (median-5 cycles)- modified DeAngelis protocol (IV Methotrexate-2.5g/m(2),IT Methotrexate-12 mg,Vincristine,Procarbazine and Rituximab-375mg/m(2) every 2 weeks) in 6 and single agent Methotrexate -3.5g/m(2) every 3 weeks in 1 patient. Severe haematological toxicities included grade 3 neutropenia, leucopenia and febrile neutropenia in 2,1 and 1 patient respectively. Radiotherapy(RT) was administered in all-whole brain RT(36-45Gy/20-25fractions/4-5weeks) in 6 patients and craniospinal RT(36Gy/18fractions/3.5weeks) followed by whole brain RT(9Gy/5fractions/1week) in 1 patient(with positive CSF cytology). Subsequently consolidation chemotherapy with 2 cycles of Cytarabine(3g/m(2) IV D1-2 every 3 weeks) was administered in 5 patients. After a median follow-up of 14 months(mean-18.2 months), all patients are in complete radiological remission. Paediatric PCNSL is a rare tumour entity and multimodality management with high dose Methotrexate and Rituximab based chemo-immunotherapy and cranial radiotherapy leads to excellent early clinical outcome.