Diagnosis and Staging:
The diagnosis of B-LBL was confirmed by expert haematopathologists on
biopsy specimens based on the standard morphologic and immunophenotypic
criteria. Staging workup included Whole-body PET/CT or Contrast-enhanced
computerized tomography (CT) scans of thorax, abdomen, and pelvis,
bilateral bone marrow aspiration/biopsy and cerebrospinal fluid
analysis. Baseline marrow flowcytometric minimal disseminated disease
(MDD) assessment by 8 to 10 color acute leukemia panel
(>5lakh events) was done and analyzed using Kaluza version
1.3™. Modified St. Jude classification was used for staging.
Treatment :
All patients were treated uniformly on a modified BFM-90
protocol8. Figure-1 depicts the treatment schema used
in the study. Following a 7-day prednisolone pre-phase, phase I 4-drug
“induction” was delivered over 4-weeks, followed by phase II
“induction” over 4-weeks; phase M contained 4-cycles of high-dose
methotrexate administered as a 24 hrs continuous infusion;
Re-intensification phase containing a truncated re-induction and
consolidation over 6-weeks, was administered to all pB-LBL patients with
advanced-stage disease (Stage III and IV). Also, a decision to give
re-intensification phase in limited-stage disease (Stage-I/II) with
baseline detectable MDD and/or PET positivity in the marrow and to
administer local irradiation for persisting residual disease
post-induction phase II irrespective of the stage was taken in
Multidisciplinary tumor boards discussions on a case-by-case basis. Both
limited and advanced-stage B-LBL patients were given oral maintenance
chemotherapy for a period of 2years. Central Nervous System
chemoprophylaxis included high dose methotrexate and intrathecal
methotrexate. Until 2013, prophylactic cranial irradiation (12.6 Gy) was
administered for CNS-1 & 2 status, and this was discontinued
thereafter, while CNS-3 patients, continued to receive therapeutic
cranial irradiation (18 Gy) after re-intensification phase. Patients
with testicular involvement at presentation and having residual disease
persisting post-induction phase II (D64) received testicular irradiation
(24 Gy) .