Presymptomatic central nervous system therapy in previously untreated childhood acute lymphoblastic leukaemia: comparison of 1800 rad and 2400 rad. A report for Children's Cancer Study Group

Early Recovery of Height Velocity in Prepubertal Children With Acute Lymphoblastic Leukemia Treated by a Short Intensive Phase Without Cranial Radiation Therapy

PURPOSE

There have been few reports on height disturbance in childhood acute lymphoblastic leukemia (ALL) patients treated without cranial radiation therapy (CRT). Our study aimed to clarify the critical period of growth in pediatric patients who were treated by the Japan Childhood Leukemia Study (JACLS) ALL-02 protocol, which involved short-term intensive treatment without CRT.

PATIENTS AND METHODS

A retrospective, cohort study was conducted for prepubertal children with B-precursor ALL who were diagnosed from July 2002 to November 2011 and treated by the JACLS ALL-02 protocol at Oita University Hospital. The heights were chronologically measured at pretreatment, after the intensive phase (INT), at the end of treatment (END), and at 1 to 5 year(s) posttreatment (POST 1 to 5).

RESULTS

Nine boys and 4 girls were enrolled. Z score of the height was reduced at INT and END. Delta Z scores of the height and Z score of height velocity were reduced from pretreatment to INT, and they demonstrated an early recovery during maintenance treatment in INT to END.

CONCLUSIONS

Early recovery of delta Z scores of the height and Z score of height velocity was observed during the INT to END period. The shortened intensive phase without CRT may result in an adequate height in prepubertal ALL patients.

Comparison of height and weight after 12 vs. 18 Gy cranial radiation therapy in pediatric acute lymphoblastic leukemia (ALL) patients

Purpose

To compare the effect of 12 versus 18 Gy cranial radiation therapy (RT) on height and weight indices among pediatric patients with acute lymphoblastic leukemia (ALL).

Methods and materials

Records of children with ALL who were 2 to 14 years old at the time of RT and were treated at a single institution between 2000 and 2011 were reviewed. Patients' height, weight, and body mass index were converted into z-scores using the Centers for Disease Control growth charts to normalize the values to number of standard deviations from the mean. These values were measured at the pre-RT clinic visit and subsequent yearly intervals. The z-scores of the growth indices were fitted into a generalizing estimating equations model and analyzed by various clinical factors.

Results

A total of 48 patients met the study criteria, including 32 boys and 16 girls. The median age at the time of RT was 7 years (range, 2-14 years). Patients were separated into 2 dose groups: 12 Gy (n = 30) and 18 Gy (n = 18). Median follow-up was 4.9 years (range, 3.0-11.8 years) and 6.0 years (range, 3.1-10.5 years) and the median pre-RT height z-scores were −0.55 (range, −2.2 to 1.4) and −0.85 (range, −3.1 to 0.8) for the 2 groups, respectively (P = .65). Patients who received 18 Gy had a significant difference in change in height compared with those who received 12 Gy, who were able to maintain normal growth during the first 3 years of follow-up. This did not appear to be sex-specific, and there was no difference in change in weight or body mass index.

Conclusions

Compared with 18 Gy, patients with ALL who received 12 Gy of cranial RT had less height impairment in the first 3 years post-RT, but further prospective studies are needed.

Magnetic resonance imaging of the brain in survivors of childhood acute lymphoblastic leukemia

The issue of delayed neurological damage as a result of treatment is becoming increasingly important now that an increased number of children survive treatment for acute lymphoblastic leukemia (ALL). Following modification of the treatment protocols, severe symptomatic late effects are rare, and most adverse effects are detected by sensitive imaging methods such as magnetic resonance imaging (MRI) or by neuropsychological testing. In this study we aimed to determine the prevalence and characteristics of late central nervous system (CNS) damage by MRI and clinical examination in children treated for ALL. A cross-sectional study was carried out at the pediatric oncology unit of Zagazig University, Egypt, and included 25 patients who were consecutively enrolled and treated according to the modified Children’s Cancer Group (CCG) 1991 protocol for standard risk ALL and the modified CCG 1961 protocol for high-risk ALL and who had survived more than 5 years from the diagnosis. All relevant data were collected from patients’ medical records; particularly the data concerning the initial clinical presentation and initial brain imaging. All patients were subjected to thorough history and full physical examination with special emphasis on the neurological system. MRI of the brain was performed for all patients. The mean age of patients was 6.9±3.04 years at diagnosis and was 12.9±3.2 years at the time of study. The patients comprised 14 boys and 11 girls. Abnormal MRI findings were detected in six patients (24%). They were in the form of leukoencephalopathy in two patients (8%), brain atrophy in two patients (8%), old infarct in one patient (4%) and old hemorrhage in one patient (4%). The number of abnormal MRI findings was significantly higher in high-risk patients, patients who had CNS manifestations at diagnosis and patients who had received cranial irradiation. We concluded that cranial irradiation is associated with higher incidence of MRI changes in children treated for ALL. Limitation of cranial irradiation to selected patients contributed to a lower incidence of neurological complications in our study. MRI is a sensitive radiological tool to detect structural changes in children treated for ALL, even in asymptomatic cases.

Lessons from the past: opportunities to improve childhood cancer survivor care through outcomes investigations of historical therapeutic approaches for pediatric hematological malignancies

Investigations of long-term outcomes have been instrumental in designing safer and more effective contemporary therapies for pediatric hematological malignancies. Despite the significant therapeutic changes that have occurred over the last five decades, therapy modifications largely represent refinements of treatment protocols using agents and modalities that have been available for more than 30 years. This review summarizes major trends in the evolution of treatment of pediatric hematological malignancies since 1960 to support the relevance of the study of late effects of historical therapeutic approaches to the design and evaluation of contemporary treatment protocols and the follow-up of present-day survivors.

Leukemias and lymphomas: treatment and prophylaxis of the central nervous system

Central nervous system (CNS)-directed therapy is required for many acute leukemia patients and for nearly all aggressive or high-grade non-Hodgkin's lymphoma patients as part of an overall chemotherapy plan for disease eradication. The CNS therapy decisions differ for overt disease treatment versus prophylactic treatment and take into consideration the type of leukemia or lymphoma, the age of the patient, and other prognostic factors. A variety of CNS-directed therapies are used for prevention or treatment of CNS disease in acute leukemias or aggressive lymphomas: intrathecal medications (cytosine arabinoside, methotrexate, or both in combination with hydrocortisone) with or without cranial or craniospinal irradiation, intrathecal medication only with intensive systemic chemotherapy, or high-dose chemotherapy specifically chosen for CNS penetrance. Any type of CNS-directed therapy, whether intrathecal chemotherapy, high-dose systemic chemotherapy, or irradiation, may cause acute or delayed (late) toxicity. Ongoing clinical trial research aims to reduce the risk of toxicity from CNS-directed therapy while preserving or improving treatment efficacy.

Very high-dose methotrexate (33.6 g/m2) as central nervous system preventive therapy for childhood acute lymphoblastic leukemia: results of National Cancer Institute/Children's Cancer Group trials CCG-191P, CCG-134P and CCG-144P

Between 1977 and 1991, the Children's Cancer Group and the National Cancer Institute conducted three trials of very high-dose methotrexate (33.6 g/m2; VHD-MTX) in place of cranial radiation (CRT) as central nervous system (CNS) preventive therapy, and assessed efficacy, acute toxicity and long-term neurocognitive outcome. CCG-191P compared VHD-MTX to CRT plus intrathecal methotrexate (IT-MTX) in 181 patients and demonstrated equivalent survival. However, patients treated with CRT had poorer performance on neurocognitive testing over time. CCG-134P evaluated the addition of intensified systemic and intrathecal therapy to VHD-MTX in 128 patients with high-risk acute lymphoblastic leukemia (ALL) and demonstrated reduced CNS relapse compared to the CCG-191P trial, but equivalent survival. CCG-144P compared VHD-MTX to IT-MTX alone in 175 patients with average-risk ALL and demonstrated equivalent survival. VHD-MTX was associated with significant toxicities, particularly neutropenia, transient hepatic dysfunction and sepsis. VHD-MTX achieved similar survival to other CNS-directed therapies without the long-term impact on intelligence, but with substantial acute toxicities.

Effects of chemotherapy on neurocognitive function in children with acute lymphoblastic leukemia: a critical review of the literature

Chemotherapy-only treatment has increasingly become the standard of treatment for childhood acute lymphoblastic leukemia (ALL). The objective of this review is to assess the present state of knowledge of the neurocognitive effects of central nervous system (CNS)-directed chemotherapy in children with ALL, and to formulate directions for future research. We performed a review of studies published since 1997, that included an ALL group treated with chemotherapy only and a control group. Twenty-one studies met our inclusion criteria. There is evidence of subtle long-term neurocognitive deficits survivors of childhood ALL after treatment with chemotherapy only. These involve mainly processes of attention and of executive functioning, while global intellectual function is relatively preserved. Young age at diagnosis and female sex emerged as risk factors.

Successful treatment without cranial radiotherapy of children receiving intensified chemotherapy for acute lymphoblastic leukaemia: results of the risk-stratified randomized central nervous system treatment trial MRC UKALL XI (ISRC TN 16757172)

Concern about late adverse effects of cranial radiotherapy (XRT) has led to alternative approaches to eliminate leukaemia from the central nervous system (CNS) in childhood acute lymphoblastic leukaemia (ALL). The Medical Research Council UKALL XI trial recruited 2090 children with ALL between 1990 and 1997. Median follow-up is 7 years 9 months; event-free survival (EFS) and overall survival were 63.1% and 84.6%, respectively, at 5 years and 59.8% and 79.4% at 10 years. The isolated CNS relapse rate was 7.0% at 10 years. Patients were randomized for CNS-directed therapy within white blood cell (WBC) groups. For WBC <50 x 10(9)/l, high-dose intravenous methotrexate (HDMTX) (6-8 g/m2) with intrathecal methotrexate (ITMTX) was compared with ITMTX alone, and was significantly better at preventing isolated and combined CNS relapse, but non-CNS relapses were similar. There was no significant difference in EFS at 10 years, 64.1% [95% confidence interval (CI) 60.4-67.8] with HDMTX plus ITMTX, and 63.0% (95% CI 59.5-66.5) with ITMTX alone. For WBC >/=50 x 10(9)/l, HDMTX with ITMTX was compared with XRT and a short course of ITMTX. CNS relapses were significantly fewer with XRT, but there was a non-significant increase in non-CNS relapses. EFS was not significantly different, being 55.2% (95% CI 47.8-62.6) at 10 years with XRT and 52.1% (95% CI 44.8-59.4) with HDMTX plus ITMTX.

White Matter and Cerebral Metabolite Changes in Children Undergoing Treatment for Acute Lymphoblastic Leukemia: Longitudinal Study with MR Imaging and1H MR Spectroscopy

PURPOSE

To assess the development of white matter and cerebral metabolite changes during and after treatment in children with acute lymphoblastic leukemia.

MATERIALS AND METHODS

Twenty-three children (10 boys, mean age of 6.3 years; 13 girls, mean age of 6.6 years) with acute lymphoblastic leukemia were examined prospectively with magnetic resonance (MR) imaging and MR spectroscopy at 0, 8, and 20 weeks and 1, 2, and 3 years after diagnosis. White matter changes were diagnosed on the basis of hyperintense abnormalities on T2-weighted MR images. Single-voxel hydrogen 1 MR spectroscopy results from the right frontoparietal region of 21 children who received intravenous high-dose methotrexate were analyzed for cerebral metabolite changes. Multilevel models were used to assess the change in metabolites from baseline levels at subsequent follow-up.

RESULTS

At 20 weeks, MR spectroscopy showed a significant reduction (P <.05) of mean N-acetylaspartate to choline ratio and increase in mean choline to creatine ratio (P <.05) in the children given high-dose methotrexate. This decline in N-acetylaspartate to choline ratio subsequently reversed and increased, possibly because of normal age-related brain maturation. Seventeen of 21 (81%) children showed metabolite changes at MR spectroscopy, while five of 22 (23%) showed white matter changes at MR imaging at 20 weeks. One more child developed white matter changes at 32 weeks. The associated changes resolved or reduced with time.

CONCLUSION

MR spectroscopy demonstrated metabolite changes in the brain after high-dose methotrexate treatment in the absence of structural white matter abnormalities at MR imaging. MR spectroscopy might thus be a more sensitive method of monitoring the effects of high-dose methotrexate in the brain.

CNS-directed therapy for childhood acute lymphoblastic leukemia: Childhood ALL Collaborative Group overview of 43 randomized trials

PURPOSE

A collaborative meta-analysis was performed to clarify the relative effects on relapse and survival of different types of therapies directed at the CNS in childhood acute lymphoblastic leukemia.

MATERIALS AND METHODS

Data were sought for each individual patient in all trials started in or before 1993 that included unconfounded randomized comparisons of such treatments. Log-rank survival analyses were performed for each trial, and overall results for groups of trials addressing similar questions were obtained from the totals of the observed minus expected number of events and their variances.

RESULTS

Radiotherapy and long-term intrathecal therapy gave similar outcomes, with no significant difference in event-free survival despite random assignment of treatment to 2,848 patients, 1,001 of whom suffered relapse or death. Intravenous methotrexate reduced non-CNS rather than CNS relapses, and hence, the addition of intravenous methotrexate to a treatment regimen including radiotherapy or long-term intrathecal therapy improved event-free survival, with a 17% reduction in the event rate (95% confidence interval, 6% to 27%; P =.003). The event-free survival at 10 years in these trials was 61.9% without intravenous methotrexate and 68.1% with intravenous methotrexate. There was no significant difference in survival (14% death rate reduction; P =.09). There were insufficient randomly assigned patients to adequately address other questions, such as effect of different doses. No evidence was found of differences, between trials or between subgroups of different types of patients, in the relative effects of treatment.

CONCLUSION

Radiotherapy can be replaced by long-term intrathecal therapy. Intravenous methotrexate gives some additional benefit by reducing non-CNS relapses.

Verbal cognitive functioning and learning in girls treated for acute lymphoblastic leukemia by chemotherapy with or without cranial irradiation

Neuropsychological problems have frequently been reported following treatment of Acute Lymphoblastic Leukemia (ALL), however, partly because of the heterogeneity of the previously studied samples, the specific nature of these deficits is still a matter of debate. These problems, however, appear to be related more to the combination of cranial radiation therapy (CRT) and intrathecal chemotherapy (ITC) than to ITC alone. In this study, we evaluated a homogenous group of 19 girls between the ages of 7 and 11 years, 30 months after the completion of treatment. Nine received cranial radiation and chemotherapy and 10 were treated with chemotherapy alone. The patients were compared to 10 normal healthy controls. Neuropsychological tests included the Wechsler Intelligence Scale for Children-Third Edition (WISC-III), the California Verbal Learning Test-Children's Version (CVLT-C), and the Calculation and Passage Comprehension subtests of the Woodcock-Johnson Psycho-Educational Battery-Revised. Results confirmed the presence ofa verbal learning deficit in ALL girls treated with the combination of ITC and CRT. The ITC and CRT group scored significantly lower than the healthy controls on the Passage Comprehension subtest and on 5 of the 6 verbal subtests of the WISC-III. Furthermore, compared to nonirradiated patients and healthy normal controls, the ITC and CRT group was impaired on the Freedom from Distractibility index of the WISC-III, indicating an auditory-verbal attention deficit. On the CVLT-C, the ITC and CRT group was particularly impaired on the second half of the learning trials compared to the other two groups, showing a plateau in their performance. The ITC group was not different from the healthy control group, suggesting a less detrimental effect of the ITC alone on verbal abilities. Globally, these results indicate a deficit affecting auditory attention and verbal learning in girls who receive ITC and CRT, which may suggest the necessity for special educational assistance for these children.

Central nervous system prophylaxis in haematological malignancies

Given the poor prognosis of central nervous system (CNS) involvement in haematological malignancies, management is directed towards prevention. CNS prophylaxis may take the form of intrathecal therapy, cranial irradiation, systemic therapy or some combination of these. The toxicity of these methods is an important consideration. A risk-orientated approach to the delivery of CNS prophylaxis in each disorder is required.

Central nervous system-directed therapy in the treatment of childhood acute lymphoblastic leukemia and studies of neurobehavioral outcome: Children's Cancer Group trials

Long-term survival rates in childhood acute lymphoblastic leukemia (ALL) have improved due, in part, to the introduction and subsequent refinements in central nervous system (CNS)-directed therapy. Studies of cognitive, motor, and behavioral functioning, which characterize the patterns and severity of CNS sequelae, are being used increasingly as measurable treatment endpoints. This paper summarizes the advances in CNS-directed therapy derived from Children's Cancer Group randomized therapeutic trials. Results from neurobehavioral outcome studies built upon these trials are also presented. A section of this review is focused on CNS-directed treatments and the neurodevelopmental outcomes of infants diagnosed with ALL, an especially high-risk patient subset. Future studies of neurobehavioral outcome are briefly elaborated in the context of current chemotherapy approaches used in the treatment of childhood ALL.

Children's Cancer Group trials in childhood acute lymphoblastic leukemia: 1983-1995

Since 1968, the Children's Cancer Group (CCG) has treated more than 16,000 children with acute lymphoblastic leukemia (ALL). Herein, we report improvements obtained in CCG trials during two successive series of studies (1983-1988 and 1989-1995). Overall, 10-year EFS was 62% +/- 10% for the 1983-1988 series and 72% +/- 1% for the 1988-1995 series (P< 0.0001). Five-year cumulative rates of isolated CNS relapses were 5.9% and 4.4%. Therapy based on the Berlin-Frankfurt-Münster 76/79 study improved outcomes for intermediate and higher risk patients in the first series. For intermediate risk patients, delayed intensification (DI) was most crucial for improved outcome and cranial irradiation was safely replaced with maintenance intrathecal methotrexate, providing patients received intensified systemic therapy. In the second series, randomized trials showed better outcome with one vs no DI phase for lower risk patients, with two vs one DI phase for intermediate risk patients, and with the CCG 'augmented regimen' for higher risk patients with a slow day 7 marrow response. Cranial irradiation was safely replaced with additional intrathecal methotrexate for higher risk patients with a rapid day 7 marrow response. In a subsequent study, substitution of dexamethasone in place of prednisone in induction and maintenance improved outcome for standard risk patients. All patients received dexamethasone in DI. These successful treatment strategies form the basis for our current ALL trials.

Long-term follow-up of childhood acute lymphoblastic leukemia in Tokyo Children's Cancer Study Group 1981-1995

The objectives were as follows: Firstly, to estimate the overall probability of event-free survival (EFS) and isolated CNS relapse in the studies for children with acute lymphoblastic leukemia (ALL) during the 1980s and 1990s. Secondly, to report the EFS according to presenting features and lineage. Thirdly, to evaluate the treatment results re-classified by the risks of NCI criteria. Four consecutive protocol studies were performed in the Tokyo Children's Cancer Study Group: L81-10 protocol (1981-1984, 189 patients), L84-11 (1984-1989, 484 patents), L89-12 (1989-1992, 418 patients) and L92-13 (1992-1995, 347 patients). Overall EFS at 5 years in each protocol was 56.5 +/- 3.8(1 s.e.)%, 71.0 +/- 2.1%, 67.8 +/- 2.3%, and 63.4 +/- 2.7%, respectively. The cumulative isolated CNS relapse rate at 5 years was 8.1 +/- 2.1%, 3.5 +/- 0.9%, 3.6 +/- 1.0%, 1.0 +/- 0.6. The EFS in SR/HR (standard risk/high risk) according to the NCI criteria in B-precursor ALL at 5 years was 61.9 +/- 4.3%/41.4 +/- 7.4% (lineage was not confirmed.), 72.5 +/- 2.6%/63.4 +/- 5.0%, 77.4 +/- 2.7%/56.3 +/- 4.7%, and 67.8 +/- 3.4%/56.7 +/- 5.4% in each protocol. Also EFSs according to NCI SR/HR at 5 years of T-ALL in protocols L84-11, L89-12 and L92-13 were 55.6 +/- 16.6%/60.9 +/- 10.1%, 72.7 +/- 13.4%/51.6 +/- 9.1%, and 77.1 +/- 14.4%/53.6/10.1%, respectively. The truncation of maintenance therapy to 6 months resulted in a decreased EFS in L92-13, particularly due to an increase of bone marrow relapse after cessation of therapy in SR and HR. The NCI risk criteria work properly even in the patients treated by different intensities, so that it makes the comparison possible among the patients in various groups. The overall EFSs in childhood ALL improved in 1980s, but it seemed stable or decreased in 1990s. The short maintenance therapy resulted in poor outcome in SR on the L92-13 protocol. Many of these late relapsers were effectively rescued and overall survival remained at a high level. The proportion of patients who received cranial irradiation reduced without any increase of the CNS events.

[Radiotherapy in leukemia excluding total body irradiation]

Radiation techniques and indications in leukemias have been described in detail, yet prophylactic cranial irradiation in acute leukemia still has few indications. Cerebrospinal and testicular irradiation are reserved for relapsing disease. Radiation usually results in rapid functional improvement when used in neurologic emergencies and symptomatic neurologic or gross tumors relapses. Nevertheless, the improvements recently obtained by systemic chemotherapy have resulted in the reduction in the use of irradiation, especially in children, where it was considered deleterious with neuropsychological sequellae. Splenic irradiation remains useful for symptomatic myeloproliferative syndrome.

Reduced incidence of the somnolence syndrome after prophylactic cranial irradiation in children with acute lymphoblastic leukemia

A prospective double blind randomized trial comparing two different dose schedules of continuous steroid coverage during prophylactic cranial radiotherapy (CRT) in leukemic children was conducted to find out the optimum dose to be prescribed to reduce the incidence of Somnolence Syndrome (SS). Between April 1994 and February 1996, 32 patients with acute lymphoblastic leukemia received CRT of 18 Gy in 10 fractions. Patients were randomized to receive oral dexamethasone of 2 or 4 mg/m2 during radiotherapy. The diagnosis of SS was made clinically based on symptoms of somnolence. All patients were followed for a minimum of 8 months. The overall incidence of SS was 40%. The development of SS was steroid dose dependent. In low dose steroid arm the incidence of SS was 64.3% (9/14), compared to 17.6% (3/17) in high dose arm with statistically significant difference (P = 0.008). The median time to development of SS was 4 weeks. The most common symptom of SS was drowsiness followed by anorexia, headache, nausea, vomiting, decreased activity, irritability, fever and ataxia, respectively. The duration of symptoms ranged from 2 to 14 days. The development of SS was not related to the presence of acute reactions, age at the time of CRT and sex. In all cases the symptoms subsided completely and spontaneously. Our results suggest that steroid coverage at a dose of 4 mg/m2 during CRT reduces the incidence of SS. However, a multicentric prospective randomized trial is needed to determine the role and the optimal dose of steroid.

Acute lymphoblastic leukemia in children: nonrandomized comparison of conventional vs. intensive chemotherapy at the National Cancer Institute of Colombia

BACKGROUND

This study aimed to compare the therapeutic efficacy of two treatments for childhood acute lymphoblastic leukemia (ALL), and to evaluate the feasibility of intensive chemotherapy in a developing country.

METHODS

The study was conducted at the National Cancer Institute in Bogota, Colombia. Untreated ALL patients under 16 years of age were divided into two groups: a historical control cohort (HC) of 141 patients treated with conventional chemotherapy and an intensive chemotherapy cohort (IC) of 130 patients treated with a modified Berlin-Frankfurt-Münster protocol (m-BFM). Patients were clinically classified into risk categories for relapse, and followed through July 31, 1995. Disease-free survival (DFS) curves were obtained using the Kaplan-Meier method and were compared by the log rank test.

RESULTS

Therapy groups had similar clinical baseline characteristics. Nonresponse rate to induction was higher in the HC group (16.3%) than in the IC cohort (7.6%) (P = 0.047), but deaths during induction were more frequent among m-BFM patients (13.8%) than in the HC group (6.4%) (P = 0.064). Bone marrow relapses after complete remission were less common in the IC group than in the HC group (19.4% and 45.9%, respectively; P = 0.0001), but central nervous system relapses showed no difference (12.8% in the HC and 16.3% under IC; P = 0.6). The DFS rates at 10 years were higher for the IC group, regardless of the baseline risk.

CONCLUSIONS

IC reduces the frequency of relapses in ALL children in developing countries, when compared to previous therapy. A highly effective therapy such as m-BFM seems to be the most important predictor of outcome in children.

The effects of irradiation and chemotherapy on growth

The effects of cancer therapy on growth are reviewed. The effects of radiation and chemotherapy on growth hormone production and growth hormone responsiveness by peripheral tissues are examined. The effects of radiotherapy and chemotherapy on other endocrine function pertaining to growth also are discussed. An approach to surveillance of pediatric cancer survivors pertaining to growth and development is suggested.

Childhood acute lymphoblastic leukemia relapse in the uterine cervix

PURPOSE

Extramedullary relapse outside the testes and CNS is rare in children with acute lymphoblastic leukemia (ALL). We describe a case of a recurrence of ALL in the uterine cervix during hematopoietic remission.

RESULTS

Primary recurrence in the uterine cervix was diagnosed by cytology with immunochemistry 43 months after initial diagnosis. She was successfully treated with systemic chemotherapy, without hysterectomy or irradiation. She remains in second complete remission 54 months after relapse.

CONCLUSIONS

Immunocytochemistry using monoclonal antibodies against cell surface antigens made the cytologic diagnosis of leukemic relapse in the uterine cervix possible. Systemic chemotherapy is the first treatment of choice for ALL recurrence in the genital tract in a patient without poor prognostic factors in order to spare gonadal function and reproductive potential.

Longitudinal growth and final height in long-term survivors of childhood leukaemia

Survival of children with acute lymphoblastic leukaemia (ALL) has increased considerably in recent years and data on the spontaneous growth and final height of these children are conflicting. Therefore, we analysed the longitudinal growth and final height in 52 survivors (33 females, 19 males) of childhood ALL. These children were diagnosed and treated in a single institution, all remained in first remission and were submitted to cranial irradiation with either 2400 or 1800 cGy. None of the patients received testicular or spinal irradiation. Median age at diagnosis was 4.2 (range 1.3-9.6) years in the first group (2400 cGy) and 3.9 (0.8-10.5) years in the second (1800 cGy). Standing height was measured at diagnosis, at the end of treatment (median 3.1 years after diagnosis), 6, 12, 24 months after the end of treatment, and finally at the completion of growth. In girls a significant decrease of mean height standard deviation score (SDS) during treatment and a catch up in growth after the end of therapy was followed by a second period of reduced growth. Mean final height SDS was significantly lower than the value at diagnosis in both groups of girls, but only in males treated with 2400 cGy. Mean overall loss in height SDS from diagnosis to final height was higher in females (-1.24) than in males (-0.40) (P = 0.009). Females < or = 4 years of age at diagnosis showed a higher loss in final height than females > 4 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult acute lymphocytic leukemia: critical review of current knowledge

PURPOSE

To analyze recent study results on adult acute lymphocytic leukemia (ALL) and discuss (1) controversies related to the optimal treatment for remission induction, maintenance, consolidation-intensification, and central nervous system (CNS) prophylaxis and (2) the role of allogeneic and autologous bone marrow transplantation (BMT).

DESIGN

Review of the English-language literature concerning studies on adult ALL and comparisons with the pediatric ALL results when appropriate.

RESULTS

Induction chemotherapy with a triple-drug regimen, including vincristine, anthracyclines, and steroids, yields the most favorable therapeutic-to-toxic ratio results. The addition of cyclophosphamide, asparaginase, or cytosine arabinoside (ara-C) to remission induction has not improved outcome. Consolidation-intensification therapy is beneficial in pediatric ALL and has been associated with increased cure rates in adult ALL, although the value of the individual components of therapy is difficult to assess. Based on the pediatric experience, future investigations in adult ALL should utilize higher dose-schedules of 6-mercaptopurine (6-MP), methotrexate, and asparaginase for consolidation-intensification therapy. The role of high-dose ara-C consolidation is not proven. Maintenance therapy with 6-MP and methotrexate is suggested based on the worse results in patients not receiving such maintenance. Allogeneic BMT is indicated in first remission in patients with high-risk for relapse (eg, Philadelphia-chromosome-positive [Ph-positive] ALL), while autologous BMT in first remission remains investigational. Mature B-cell ALL requires short-term/dose-intensive therapy with alternating hyperfractionated doses of cyclophosphamide and high doses of ara-C and methotrexate. T-cell ALL may benefit from ara-C plus cyclophosphamide consolidations. Based on certain risk features (ie, older age, high presenting white blood cell count, non-T-cell immunophenotype, Ph-positive karyotype, longer time to achieve remission), a high-risk group for systemic relapse (60% to 70% of patients) is identified with an expected cure rate of 20% to 25%; low-risk patients have an expected cure rate of 60% to 70%. Intrathecal chemotherapy may be sufficient as CNS prophylaxis, and its duration based on the expected risk of CNS relapse.

CONCLUSION

Improvement in adult ALL prognosis has been modest. Future strategies may investigate increasing the dose-intensity of induction and consolidation-intensification therapy, incorporating new anti-ALL agents into the regimens, improving autologous BMT results (eg, purging, conditioning regimens), and appropriately using risk-oriented investigational strategies.

Central nervous system directed therapy in acute lymphoblastic leukaemia

CNS-directed treatment is an essential component of therapy for both children and adults with acute lymphoblastic leukaemia. The choice between combinations of i.t. drugs, radiotherapy and high-dose systemic chemotherapy is not a clear one and will depend on the age of the patient, the type of leukaemia and indeed the available treatment facilities. A plea is made for any prospective trials of CNS-directed therapy to incorporate formal assessment of neuropsychological performance, and in the young child, of growth and pubertal progression.

Shedding of CD9 antigen in acute lymphoblastic leukemia

A leukemia-associated CD9 glycoprotein antigen released into the extracellular milieu from acute lymphoblastic leukemia cells has been detected using a unique lectin-monoclonal antibody immunoassay. It has been demonstrated that the release of CD9 antigen is an active process and is associated with active cell growth. In addition, the difference of carbohydrate moiety, and hence glycosylation, in the CD9 antigen derived from lymphoblasts and neuroblasts was verified using lectin affinity chromatography. The lectin affinity of the carbohydrate moiety of lymphoblast CD9 antigen would indicate the presence of N-linked oligosaccharide chains having groups of N-acetyl glucosamine residues, a mannose core and a terminal D-galactose. The soluble CD9 antigen is specifically detected in plasma from ALL patients at the time of diagnosis, in cerebrospinal fluid from patients with central nervous system involvement, and spent medium from CD9-positive leukemic blasts obtained at the time of diagnosis. Interestingly when bone marrow cells taken from patients in complete remission were studied, a distinct amount of CD9 antigen was released into spent medium in some of the cases. All of these patients have subsequently developed hematological relapse. The present data suggest that shedding of CD9 antigen by leukemic cells may enable the clinical monitoring of residual leukemic cell burden.

Adrenocorticotrophin and cortisol secretion in children after low dose cranial irradiation

OBJECTIVE

We investigated the effect of low dose cranial irradiation (18-24 Gy) on spontaneous ACTH and cortisol secretion in children.

DESIGN

We analysed 24-hour plasma ACTH and cortisol profiles sampled at 20-minute intervals.

PATIENTS

Twenty long-term survivors of acute lymphoblastic leukaemia were studied and results compared with those in 14 normal children.

MEASUREMENTS

ACTH and cortisol profiles were analysed by Fourier transformation and spectral analysis of stationarized data, autocorrelation and coherency analysis.

RESULTS

The normal circadian rhythms of ACTH and cortisol were preserved in the children after cranial irradiation. The median 0900 h and midnight values were 1.50(0.8-6.4)pmol/l and 1.0(0.6-3.7)pmol/l respectively for ACTH and 282(48-1913)nmol/l and 57.5(44-637)nmol/l respectively for cortisol, and were not significantly different from those in the normal group. Fourier transformation revealed dominant periodicities for ACTH at 0.7-1.1 h, equivalent to 22-34 ACTH secretory bursts per 24 hours, and for cortisol at 0.7-1.1 h and 2-4.8 h. Similar results were found in the normal group. Coherency analysis indicated a significant shared periodicity of 0.7-1.2 h in nine children, corresponding to 20-34 related secretory bursts in 24 hours for ACTH and cortisol. After pooling the coherency spectra in the cranially irradiated group, comparison with the pooled data from the normal group revealed no significant difference between the two groups in the relationship between the two hormones.

CONCLUSION

No significant disruption of spontaneous ACTH or cortisol secretion, either in the amount or pattern of hormones secreted, was found in children after low dose cranial irradiation (18-24 Gy).

Low leukocyte counts with blast cells in cerebrospinal fluid of children with newly diagnosed acute lymphoblastic leukemia

BACKGROUND

Treatment of the central nervous system is crucial to the successful treatment of acute lymphoblastic leukemia in children. The intensity and timing of the therapy are based on the presence or predicted risk of central nervous system leukemia as assessed according to criteria that remain controversial.

METHODS

The clinical importance of leukemic blast cells detected in cerebrospinal fluid at the time of diagnosis was evaluated in 351 children with acute lymphoblastic leukemia in a randomized trial of intensive chemotherapy. All patients received intrathecal chemotherapy during the first year. Patients considered to be at high risk of relapse because of their clinical and cytogenetic features also received cranial irradiation and intrathecal chemotherapy one year after remission. Patients were considered to have central nervous system leukemia at diagnosis if they had at least 5 leukocytes per microliter of cerebrospinal fluid, with leukemic blast cells apparent in cytocentrifuged preparations, or cranial-nerve palsy; they received additional intrathecal injections of chemotherapeutic agents and cranial irradiation. Patients were retrospectively classified on the basis of cerebrospinal fluid findings: 291 patients had no detectable blast cells, 42 had fewer than 5 leukocytes per microliter and blast cells, and 18 had central nervous system leukemia as defined above. The clinical characteristics and outcomes of treatment in these groups were analyzed.

RESULTS

The five-year probability of survival free of relapses confined to the central nervous system in patients with detectable blast cells and fewer than 5 leukocytes per microliter of cerebrospinal fluid was lower than in patients without blast cells (mean [+/- SE], 87 +/- 13 vs. 96 +/- 2 percent), but was not different from the probability in patients with central nervous system leukemia at diagnosis. All such isolated relapses of leukemia in patients with detectable blast cells occurred during the first year of treatment, before scheduled cranial irradiation. In a multivariate analysis, the presence of cerebrospinal fluid blast cells with fewer than 5 leukocytes per microliter was independently related to the risk of relapse confined to the central nervous system.

CONCLUSIONS

Patients with leukemic blast cells in their cerebrospinal fluid are at increased risk for central nervous system relapse when cranial irradiation is delayed. Such patients require intensified central nervous system treatment early in the course of therapy.

Final height after treatment for childhood acute lymphoblastic leukemia: comparison of no cranial irradiation with 1800 and 2400 centigrays of cranial irradiation

We analyzed growth and final heights in 127 patients (68 female patients) treated for childhood acute lymphoblastic leukemia. Central nervous system prophylaxis included either no cranial radiation therapy (CRT) (n = 38), irradiation with 1800 centigrays (cGy) (n = 36), or irradiation with 2400 cGy (n = 53). None of the patients received spinal irradiation. Mean (+/- SEM) age at diagnosis was 6.4 +/- 0.25 years, mean height standard deviation score (SDS) at diagnosis was 0.28 +/- 0.12, and mean age at final height was 18.26 +/- 0.19 years. The change in height SDS between diagnosis and achievement of final height was significant for all treatment groups: -0.49 +/- 0.14, no CRT; -0.65 +/- 0.15, 1800 cGy; and -1.38 +/- 0.16, 2400 cGy. Irradiated patients had a greater loss in height SDS compared with the nonirradiated patients (p < 0.01), and those treated with 2400 cGy CRT had a greater decrease in final height SDS than the patients treated with 1800 cGy (p < 0.01). Both younger age and female sex were significantly associated with a greater decrease in height SDS in the patients treated with CRT; girls < or = 4 years of age at diagnosis had a mean loss in height SDS that was more than twice that observed for others treated with the same dose of CRT. Thus, although modern regimens for acute lymphoblastic leukemia (no CRT or 1800 cGy CRT) appear overall to have only a modest impact on final height, patients, especially girls, treated with 1800 cGy CRT at a young age remain at risk for clinically significant growth failure.

An odyssey in search of a cure: the evolution of treatment of childhood acute lymphoblastic leukemia in the United Kingdom

This review charts the evolution of therapy for childhood acute lymphoblastic leukaemia (ALL) in the United Kingdom. The present chemotherapeutic regimen is the result of experience gained from carefully planned randomised cooperative studies carried out during the last two decades. In common with the experience of the West German and American groups, the best results have been in those treated with post remission intensification blocks. With current chemotherapy protocols, almost 70% of children with ALL in U.K. can be cured but there may be a medical cost of such a cure, in terms of both acute and long term toxicity. This was especially true when central nervous system (CNS) therapy with cranial irradiation was used. Therefore present regimens are examining chemotherapeutic options for CNS disease control and the efficacy of additional post remission intensification. Failure of chemotherapy is most often seen in those children with a presenting white cell count of more than 50 x 10(9)/l, very young children and/or the presence of certain chromosomal rearrangements (e.g. t4: 11, t9: 22). At present the optimum therapeutic option for such high risk patients and for the majority of those in second remission, is an allogenic bone marrow transplant if an HLA-matched sibling is available. Modern day therapy is both complicated and costly and will be beyond the resources available for most children with ALL in developing countries. A significant decrease in worldwide mortality due to ALL will only occur if either the disease can be prevented or a simpler cure devised.

Cranial computed tomography in children with acute lymphoblastic leukemia after prophylactic treatment with cranial radiation therapy and intrathecal methotrexate

BACKGROUND AND METHODS

Thirty-one children with acute lymphoblastic leukemia (ALL) who had received cranial radiation therapy (CrRT) and five concomitant doses of intrathecal methotrexate (IT MTX) for central nervous system prophylaxis (CNSP) and who had an event-free survival exceeding 5 years had cranial computed tomography (Cr CT) examination. The fractional dose for 21 of them was 1.5 Gy. The interval between the completion of CNSP and the time of Cr CT ranged from 5 to 8.5 years, with a median of 5 years 2 months.

RESULTS

Unlike the previous reports in the literature that 9-77% of children with ALL who had received Cr RT 18 Gy and IT MTX as CNSP had CT scan abnormalities, in this study no patient had CT scan abnormalities.

CONCLUSIONS

Our results might be attributable to the fractional dose of Cr RT being adequate, the IT chemotherapy being suitable, and the systemic chemotherapy not being intensive.

Unusual presentation of common acute lymphoblastic leukemia antigen-positive extramedullary disease in childhood. Two patients with isolated masseter muscle involvement

Two children with unusual extramedullary common acute lymphoblastic leukemia antigen (CALLA)-positive (CD10) disease are reported. Isolated masseter infiltration with CD10/CD19-positive lymphoblasts was present in both patients with no other evidence of disease. One child had relapse of common acute lymphoblastic leukemia, and the other had primary disease. Disease may have spread from lymph nodes overlying the masseter muscle. Immunophenotyping and immunogenotyping provided a rapid and accurate diagnosis for both children.

Hyperfractionated, twice-a-day, radiotherapy may decrease IQ deterioration due to prophylactic cranial irradiation in childhood acute lymphoblastic leukemia: a radiobiological analysis

High cure rates in childhood acute lymphoblastic leukemia (ALL) are being achieved with aggressive systemic chemotherapy and treatment to sanctuary sites including prophylactic cranial irradiation. However, IQ deterioration is a dreaded complication of prophylactic cranial irradiation. IQ deterioration is a late sequela. Since there is evidence--both radiobiological and clinical--to suggest that acute tissue (including tumor) response and late tissue response can be separated by hyper-fractionation, we propose a twice-a-day radiotherapy in prophylactic cranial irradiation of childhood ALL to decrease delayed toxicity. Analysis based on current radiobiological models favors such a treatment scheme. However, only a prospective clinical trial can confirm whether IQ deterioration can be prevented or decreased with hyper-fractionated radiotherapy.

Irradiation-induced growth failure

GH deficiency, skeletal disproportion and early or precocious puberty may complicate irradiation to the head or axial skeleton in childhood. Certain cohorts of children are at particular risk, including those irradiated for brain tumours and various haematological malignancies. Both GH deficiency and impaired spinal growth may result in short stature, whereas the occurrence of early puberty in association with GH deficiency reduces the time available for GH therapy. The age of the child at irradiation is critical in that, in younger children, the central nervous system is more radiosensitive, the severity of the subsequent skeletal disproportion is greatest and the onset of puberty earliest. It is the very young craniospinally-irradiated child who is most at risk of extreme short stature.

A novel variant of growth hormone (GH) insufficiency following low dose cranial irradiation

OBJECTIVE

We aimed to investigate the effect of low dose (1800 cGy) prophylactic cranial irradiation on physiological growth hormone secretion.

DESIGN

We performed an analysis of 24-hour serum GH profiles using 20-minute sampling.

PATIENTS

Forty-four children were studied, of whom 21 were long-term survivors of acute lymphoblastic leukaemia and 23 were normal children. They were further subdivided into prepubertal, pubertal and post-pubertal groups.

MEASUREMENTS

GH profiles were analysed by autocorrelation, Fourier transformation and spectral analysis of stationarized data, and peak detection using the Pulsar peak detection program. RESULTS In the normal children, there was a significant increase in the median (range) area under the curve (AUC) of the GH profile between the prepubertal and pubertal groups (62 (11-124) and 137 (142-158) IU/I/h respectively, (P less than 0.01)). There was also a change in the spectral analysis through puberty. The dominant frequencies were spread widely in the prepubertal and post-pubertal groups but sharply focused in the pubertal group. In the cranially irradiated children there was no significant increase in AUC between the prepubertal (62(13-110) IU/I/h) and pubertal groups (92 (14-163) IU/I/h). The wide range of dominant frequencies persisted in the pubertal cranially irradiated group due to the presence of additional high frequency pulses. The impression of a disturbance of the periodicity of GH secretion in the cranially irradiated pubertal group was further supported by the finding that the autocorrelation function in this group alone was not significantly different from that which would arise from random data.

CONCLUSIONS

A novel form of GH insufficiency has been observed after low dose irradiation in childhood in which an abnormality of periodicity and a quantitative reduction in GH secretion appears restricted to puberty.

Prophylactic cranial irradiation dose effects on late cognitive function in children treated for acute lymphoblastic leukemia

Prophylactic central nervous system treatment has dramatically improved the disease-free survival of children with acute lymphoblastic leukemia (ALL). Long-term neuropsychological sequelae are documented in children who received 2400 cGy prophylactic cranial irradiation. The dose was reduced to 1800 cGy. Available reports on developmental consequences, with short follow-up, have yielded inconsistent results. This study assesses radiation dose effects on cognitive function in children with leukemia who received central nervous system prophylaxis with 2400 cGy versus 1800 cGy whole brain radiotherapy. All leukemic children also received intrathecal methotrexate. A control group of children (treated for Wilms' tumor) received no central nervous system therapy. Nineteen children were treated with 2400 cGy, 16 children with 1800 cGy. The 12 control children received no irradiation. All patients were off therapy for at least 70 months. The 1800 cGy and 2400 cGy patient groups were off therapy for equivalent periods of time (range 70-123 mo) at follow-up testing. Mean age at diagnosis was 49 months, at testing: 142 months. The male to female ratio was 1/1. Standardized psychological tests were administered. Full-Scale, Verbal, and Performance IQ were measured with the Wechsler Intelligence Scale for Children-Revised. Wide Range Achievement Testing evaluated reading, spelling, and arithmetic abilities. Children treated with 1800 cGy performed significantly better than those who received 2400 cGy, and at the same level as controls. There were statistically significant differences between the 1800 cGy and 2400 cGy subjects in all measures. 2400 cGy patients had deficiencies in IQ and academic performance. 1800 cGy patients scored approximately 12 points higher than 2400 cGy children. Eleven children, two in the control group, two in the 1800 cGy, and seven in the 2400 cGy group had IQ scores of less than 90. Eight of the nine irradiated children with deficits had radiotherapy before age 5. These results indicate a mild, but diffuse information processing deficit in children who received 2400 cGy, but not in children who received 1800 cGy. These findings with a minimum of 6 years of follow-up provide new information on late effects of CNS prophylaxis in ALL. Reducing the cranial RT dose from 2400 cGy to 1800 cGy reduced neurotoxicity to acceptable levels.

Cognitive function in children with leukemia. Effect of radiation dose and time since irradiation

The effect of two cranial radiation (CRTX) doses and the time since radiation therapy on cognitive functioning were studied in 35 children who completed therapy for acute lymphoblastic leukemia (ALL). The patients were grouped according to CRTX dose (2400 or 1800 cGy) and evaluated for general intelligence, academic achievement, and visual motor integration. Those who received 2400 cGy (n = 20) scored ten points below those treated with 1800 cGy (n = 15) on verbal intelligence quotient and achievement tests of reading, spelling, and arithmetic. The effect of time since radiation therapy on these measures of cognitive function was significant (P = 0.001 to 0.03); the effect of CRTX dose was not. Visual motor integration scores in both groups fell below the 33rd percentile. The effect of CRTX dose and time since radiation therapy on visual motor integration and performance intelligence quotient were not significant. Thus, the interval between treatment and the emergence of cognitive impairments may be longer after lower CRTX doses, and deficits in nonverbal areas such as visual motor integration may appear first. A larger study is needed to confirm these findings from a limited sample of long-term survivors of ALL.

A pilot study of monoclonal antibody targeted radiotherapy in the treatment of central nervous system leukaemia in children

A pilot study was performed to investigate the toxicity, pharmacokinetics and therapeutic effect of intrathecally administered radiolabelled monoclonal antibody (MAb) in patients with meningeal acute lymphoblastic leukaemia (ALL). Six children aged 3-16, in second or subsequent central nervous system (CNS) relapse of ALL, received between 629 and 1480 MBq of 131Iodine conjugated to either MAb HD37 (CD19, n = 2) or WCMH15.14 (CD10, n = 4). Conjugate was administered as a single injection either via an Ommaya reservoir (n = 4) or by lumbar puncture (n = 2). Acute toxicity was manifest by headache (n = 4), nausea and vomiting (n = 4) and pyrexia (n = 2). All acute symptoms resolved within 72 h. Transient myelosuppression occurred in three patients. Pharmacokinetic studies included investigation of whole body, blood and CSF clearance of isotope. 131I was seen to clear from the CSF by biexponential kinetics. Five patients responded to therapy. In four, the CSF became clear of blast cells at both 2 and 4 weeks following antibody injection, but evidence of relapse was seen at 6 weeks. The fifth patient, with blast cells present on a cytospin preparation, responded to therapy over an 8-week period but relapsed at 12 weeks. This study demonstrates the potential of targeted radiotherapy in CNS ALL, but further studies are necessary to increase the length of remission.

Second intracranial neoplasms following treatment of childhood acute lymphoblastic leukaemia

We report a boy with acute lymphoblastic leukaemia (ALL) treated with chemotherapy and prophylactic cranial irradiation to a dose of 24 Gy. Six years after diagnosis he developed a glioma and died. Prior to 1979, four cases of second malignant neoplasm (SMN) of the brain had been reported in children treated for ALL. These SMNs occurred within 2 years of the original diagnosis (median 1.3 years) and at least two of four patients had not received prior radiotherapy. Since 1979, 28 cases of SMN of the brain have been reported including nine of 468 (1.9%) long-term survivors in one study. All occurred more than 3.7 years from diagnosis (median 6.5 years; range 4-13 years) and all received cranial irradiation (median 24 Gy; range 20-48 Gy). These data indicate a change in the pattern of SMNs which is most likely due to the introduction of cranial irradiation. As well, the frequency of SMNs in children treated for ALL appears to have increased, although it is still no greater than the risk of SMNs developing following the treatment of any other primary childhood neoplasm.

Osteoporosis after cranial irradiation for acute lymphoblastic leukemia

A prospective study was conducted to investigate the possibility of osteoporosis after treatment for childhood acute lymphoblastic leukemia (ALL). Forty-two survivors of ALL had the trabecular bone density of the spine evaluated by quantitative computed tomography, 6 to 98 months (mean 42 months) after completion of chemotherapy. The ALL survivors had significantly lower bone density than age-, gender-, and race-matched nonleukemic control subjects had (10% less, p less than 0.001); this decrease was accounted for solely by the subset of patients who had received cranial irradiation (n = 30; p less than 0.001). The relative reduction in bone density in ALL survivors was unrelated to age at the time of diagnosis or time without therapy. The effects on bone density of 18 Gy and of 22.5 to 25.2 Gy were indistinguishable. We conclude that survivors of ALL commonly have reduced bone density in the lumbar spine and suggest that the diminution is related to nervous system irradiation, not to the disease or to chemotherapy.

Neurotoxicity in lymphoblastic leukaemia: comparison of oral and intramuscular methotrexate and two doses of radiation

Serial cranial computed tomograms were carried out in 136 children with acute lymphoblastic leukaemia who were receiving 24 Gy or 18 Gy of cranial irradiation and continuing treatment with doses of methotrexate given weekly orally or intramuscularly. The findings were correlated with treatment variables, the development of fits, and the intelligence quotient (IQ). Reversible brain shrinkage, attributed to treatment with steroids, was found on 87 of 114 initial scans (76%); 14 showed changes in white matter during treatment (10%), and calcification was found in 13 either during or after treatment (10%). Eight children (6%) had fits, and in six of the eight there were changes in white matter or calcification on the scans. Comparison of the two radiotherapy dosages showed no difference in the incidence of abnormalities seen on computed tomography, fits, or serial IQ measurements, but children receiving intramuscular methotrexate had a higher incidence of calcification and a lower mean IQ at one year than those who received the drug orally, although this difference was not apparent later. Younger children were more likely to develop changes on computed tomograms and fits, and to have low IQs on completion of treatment, with changes most apparent in those less than 2 years of age. There were highly significant correlations between abnormalities on computed tomography, fits, and IQ. These findings confirm the neurological vulnerability of younger children with acute lymphoblastic leukaemia, show an association between abnormalities on computed tomography and intellectual deficit, and suggest that methotrexate is more toxic when given intramuscularly than orally. They provide no evidence that 18 Gy of cranial irradiation is less toxic than 24 Gy, and indicate the need for alternative treatment regimens.