Correlation between cranial computed tomographic scans at diagnosis in children with acute lymphoblastic leukaemia and central nervous system relapse

Increased risk of neurological relapse in acute lymphoblastic leukemias with high levels of cerebrospinal fluid thymidine kinase at diagnosis

Cerebrospinal fluid thymidine kinase (CSF-TK) was measured at diagnosis in 62 patients with acute lymphoblastic leukemia (ALL) without initial neurological manifestations, who achieved a complete remission after chemotherapy. During the follow-up period, 10 patients developed central nervous system (CNS) involvement. At the onset of the disease mean CSF-TK levels in these subjects were found to be significantly higher than those observed in patients without subsequent CNS complications. In particular, 7/10 (70%) of these patients who presented CSF-TK levels above the upper limit of normal (1.4 U/microliters) had evidence of a neurological relapse, while 49/52 (94.2%) of subjects with presenting CSF-TK levels of up to 1.4 U/microliters did not develop a neurological leukemic disease (p < 0.00001). The white blood cell count at diagnosis was significantly increased, but not directly correlated to CSF-TK levels, in the group with CNS involvement, while age, serum thymidine kinase levels and lactic dehydrogenase, FAB classification or immunophenotype were not different in patients with or without neurological relapse. In conclusion, increased levels of CSF-TK at presentation correlate with a high risk of subsequent CNS involvement in patients with responsive ALL.

Cranial computed tomographic findings in children with newly diagnosed acute lymphoblastic leukemia: a prospective follow-up study during treatment

Cranial computed tomography (CT) was performed on 40 consecutive children with newly diagnosed acute lymphoblastic leukemia (ALL) on admission before any chemotherapy, 5 months after CNS therapy (n = 39) and after 2 to 3 years of therapy (n = 31). Changes related to leukemia were found in only 10% of the patients at the time of diagnosis (4/40). These initial changes, two intracranial hemorrhages, one dural thickening and one contrast enhancement, all disappeared during therapy. The findings which persisted unchanged in the next two CT scans were thought to be normal variations or caused by earlier disorders. CNS therapy consisted of intrathecally and intravenously administered methotrexate in 20 standard risk (SR) patients and cranial irradiation in addition to chemotherapy in 19 intermediate risk (IR) or high risk (HR) patients. Four SR patients developed changes during therapy. Three had enlarged cerebrospinal fluid (CSF) spaces and one developed a focal low density area suggesting disturbances in brain blood circulation and also experienced disturbances in level of consciousness. Of the 19 IR or HR patients, eight developed changes related to the therapy, including four with white matter hypodensity areas, of whom three also had enlarged CSF spaces, and four others who developed enlarged CSF spaces. The medians of the widths of the cortical sulci (P less than .001), insular cisterns (P less than .01), third ventricles (P less than .01), and frontal horns (P less than .05), and also of Evans' ratios (P less than .05) increased significantly after CNS therapy as compared with the findings at diagnosis in the patients who had received cranial irradiation. Most of these changes persisted during the follow-up. We conclude that the clinical value of CT scanning during therapy for ALL is restricted to patients with neurological symptoms or those who have undergone CNS irradiation.