Sanctuary sites in Acute Lymphoblastic Leukemia

  • Sanctuary sites in acute lymphoblastic leukemia refers to areas where the leukemia cells are protected from the systemic chemotherapy
  • CNS and testis are the important sanctuary sites for ALL
  • These leukemic cells can produce relapse later and hence should be taken care of

CNS prevention therapy for Acute Lymphoblastic Leukemia:

  • As the chemotherapeutic agents do not cross the blood brain barrier, intrathecal methotrexate and cranial irradiation is used to kill leukemia cells residing in the CNS
  • This results in increased survival rates but have also causes neurotoxicity and increased risk for CNS malignancies
  • To decreased neurotoxicity, experts now recommend a lower dose of CNS irradiation (1800cGy) with intrathecal methotrexate
  • Also triple regimen intrathecal chemotherapy (methotrexate, hydrocortisone and cytarabine) without CNS irradiation is also considered