Sentence: Preoperative treatment was 5 fractions radiation therapy ( 25 Gy to involved mesorectum , 20 Gy to elective nodes ) , followed by 4 cycles of FOLFOX [ 5-fluorouracil , oxaliplatin , leucovorin ] .
Drug combination annotation:
[{'class': 'POS', 'spans': ['oxaliplatin', 'leucovorin', '5-fluorouracil'], 'is_context_needed': True}]