Assessment of Cranial Radiotherapy Treatment in T-cell Lymphoblastic Lymphoma: Retrospective Study from Tertiary Care Center

Abstract

Abstract Introduction Leukemia-like regimens given for acute lymphoblastic leukemia (ALL) are the cornerstone of treatment for T-cell lymphoblastic lymphoma (LBL) and can produce complete remission rates exceeding 90%. For central nervous system (CNS) prophylaxis, intrathecal chemotherapy and cranial irradiation are used to prevent future CNS recurrence. Objective The purpose of this study was to assess CNS relapse rate after cranial prophylaxis treatment given at our institute. Materials and Methods In this retrospective analysis, between July 2013 and June 2019, 149 files of lymphoblastic lymphoma were reviewed. Out of these, 53 patients received cranial irradiation. All patients were given CNS-directed therapy in the form of intrathecal methotrexate and patients with CNS-negative disease and primary tumor complete response or more than partial response after chemotherapy were given prophylactic cranial irradiation (18 Gy/10#), and in patients with upfront CNS involvement, therapeutic cranial irradiation (24 Gy/12#) was delivered. Radiotherapy was delivered as per the standard conventional protocol on a linear accelerator. Results Out of 53 patients (age range: 2–50 years, mean–16.79 years, 26 [49.1%] pediatric [<14 years], 27 [50.9%] adults [>14 years]), 13/53 (24.5%), and 40/53 (75.5%) patients were on MCP 841 and BFM 90 protocols, respectively. Also, 48 (90.56%) patients received prophylactic cranial irradiation (25 [52.1%] pediatric, 23 [47.9%] adults). Moreover, 3/48 (6.25%) (2 [4.16%] pediatric, 1 [2.08%] adult) patients had CNS failure after receiving prophylactic cranial irradiation. For 48 target patients, with the median follow-up of 27.27 months (26.1 months–pediatric, 28.2 months– adults), EFS (event-free survival) in the brain was 93.8% (92%: pediatric, 95.7%: adults). Also, the difference between pediatric and adult groups was not statistically significant (p-value = 0.662). Five (9.43%) patients had CNS-positive disease upfront and received therapeutic cranial irradiation. Conclusion In BFM 90/MCP 841 protocol in lymphoblastic lymphoma, prophylactic cranial irradiation and intrathecal methotrexate have been the standard of care as the CNS-directed therapy to prevent cranial infiltration. Though our results are not at par with the published world literature, further research and efforts are required to prevent CNS relapse in a selected sub-set of patients with lymphoblastic lymphoma.