Intermediate dose methotrexate (IDM) in childhood acute lymphocytic leukemia (ALL)

The use of intermediate dose methotrexate in increased risk childhood acute lymphoblastic leukemia. A comparison of three versus six courses

Between January 1974 and November 1978, 41 consecutive increased risk (age less than 24 months or less than 120 months, or leukocyte count greater than 30,000/mm3) patients with acute lymphoblastic leukemia (ALL) were entered on two consecutive treatment protocols which employed intermediate dose methotrexate (IDM). IDM was employed for central nervous system prophylaxis and systemic intensification. It was anticipated that the avoidance of prophylactic cranial irradiation would result in a lower incidence of longterm central nervous system sequelae. Twenty-two children and adolescents were entered on the first study (IDM X 3) which employed three courses of IDM (500 mg/m2) and six doses of intrathecal (IT) methotrexate (MTX). Nineteen children and adolescents were entered on the second study (IDM X 6) which employed six courses of IDM (3-500 mg/m2 and 3-1500 mg/m2), six doses of IT MTX and three additional doses of triple IT chemotherapy (MTX, cytosine arabinoside, and hydrocortisone or dexamethasone). The cumulative percentage of patients who remained in continuous complete remission was 30% for IDM X 3 and 57% for IDM X 6. This difference was statistically significant (P = 0.046; and BM + CNS, I-using IDM X 6. The cumulative incidence of primary CNS relapse was 36.4% for IDM X 3 and 29.9% for IDM X 6. This difference was not statistically significant (P = 0.44). The use of more intensive therapy with IDM and triple IT chemotherapy did improve the duration of continuous, complete remission but did not decrease the incidence of primary CNS relapse in increased risk patients.

Computed tomography brain scans in children with acute lymphocytic leukemia receiving methotrexate alone as central nervous system prophylaxis

Central nervous system (CNS) "prophylaxis" is critical in the treatment of acute lymphocytic leukemia (ALL). The standard method employed combines cranial radiation (CRT) and intrathecal methotrexate (IT MTX). Recently, a 52% incidence of abnormal computed tomography (CT) brain scans was found in asymptomatic children with ALL whose CNS prophylaxis consisted of CRT and either IT MTX or intrathecal cytosine arabinoside (IT Ara-C). In the present study, CT brain scans were studied in 43 asymptomatic children with ALL in continuous complete remission. The CNS prophylaxis consisted of IT MTX alone in 10 patients and IT MTX combined with intermediate-dose intravenous MTX in 33 patients. No patient had received CRT. The patients' ages at the time of diagnosis ranged from 22 months to 17 years, 7 months. The time interval from completion of CNS prophylaxis to CT scanning ranged from ten to 59 months. Only one CT scan was clearly abnormal; it showed mildly dilated ventricles and visualization of the cortical sulci. The CT scans of 7 additional patients were classified as abnormal because of borderline dilatation of the lateral ventricles (3 patients) and/or visualization of the cortical sulci (7 patients). No patient demonstrated areas of decreased cerebral attenuation coefficient or intracerebral calcification--findings previously ascribed to the use of methotrexate. Clinical leukoencephalopathy has not been observed in any of our patients. This would suggest that MTX alone in the absence of CNS leukemia or CRT is highly unlikely to produce structural CNS abnormalities detectable by CT.