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J Boos

Publications and source records attributed to J Boos.

At least 73 records · Page 4Linked to original sources
PubMed1992

Investigation of the variability of etoposide pharmacokinetics in children.

PROBLEM: The interindividual variation of etoposide pharmacokinetics under different therapeutic schedules and the rationale of dose reduction in young children and newborns were investigated in the present study. PATIENTS AND METHODS: We evaluated pharmacokinetic parameters during short-term infusion in 21 therapy cycles (18 children) on different therapeutic schedules (66-200 mg/m2). In 33 patients state levels (Css) during continuous infusion of 125 mg/m2/96 h were analyzed by an HPLC-method. RESULTS: During short-term infusion half-life (3.3 +/- 0.7 h) and total body clearance (26 +/- 6 ml/min/m2) showed a relatively narrow range. Calculation of the area under the curve was standardized to a dosage of 100 mg/m2 (AUC/[100 mg/m2]). The AUC then was 68 +/- 17 (micrograms.h/ml)/(100 mg/m2) with a coefficient of variation of 25%. In the subgroup of 10 patients who received 150 mg/m2 the AUC was 106 +/- 15 micrograms.h/ml with only 14% coefficient of variation. In children < 2 years, pharmacokinetic parameters were within the normal range. Calculation of the doses the short-term infusion per kg resulted in a dose reduction or 31% (mean, n = 5) and in 22% (mean) lower AUC's. With continuous infusion of 125 mg/m2 etoposide the interpatient variability was greater with a 33% coefficient of variation of the Css (4.4 +/- 1.4 micrograms/ml; n = 24). Calculation of the doses per kg (age < 1 year) or 2/3.kg resulted in reduced Css. Standardization of these levels showed Css (125 mg/m2) of 4.6 +/- 1.4 micrograms/ml and a coefficient of variation of 31%. CONCLUSIONS: Interpatient variability of etoposide pharmacokinetics at least during short-term infusion is limited. Dose reduction is not substantiated in children < 2 years by our pharmacokinetic data.

Child↗
PubMed1992

Acute myelogenous leukaemia in children under 2 years--experiences of the West German AML studies BFM-78, -83 and -87. AML-BFM Study Group.

Clinical, morphological, immunological, cytogenetical and prognostic features of 84 children under 2 years of age with AML in studies AML-BFM-78, -83 and -87 were retrospectively analysed. There was a high incidence of acute monoblastic leukaemia (FAB M5) (41 patients--49%) and acute megakaryoblastic leukaemia (FAB M7) (study AML-BFM-87: five patients--13%) in this age group. Acute monoblastic leukaemia was associated with hepatosplenomegaly, extramedullary organ manifestations and chromosomal abnormalities involving 11q23. The probability of an 11-year event-free survival of all patients under 2 years of the three studies combined was 39% (SD 6%). While the event-free survival rates of patients aged 2 years and older could be improved in studies AML-BFM-83 and -87 compared with study AML-BFM-78, overall prognosis in children under 2 years in the three consecutive studies remained unchanged. The event-free survival rate of children with acute monoblastic leukaemia in both age groups was comparable (7 yr-EFS (AML-BFM-83 and -87): much less than 2 years--43% (SD 9%), =/much greater than 2 years--33% (SD 9%); P much greater than 0.5). This also applied to other risk groups. In conclusion, taking the high incidence of acute monoblastic and megakaryoblastic leukaemia in children under 2 years into account, no significant differences between children under 2 years or older children concerning response to therapy and overall prognosis could be evaluated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Urinary excretion of the enantiomers of ifosfamide and its inactive metabolites in children.

The precondition for the antineoplastic effect of ifosfamide (ifo) is the oxidation of the oxazaphosphorine ring system, which contains a chiral centre at the phosphorous atom. This "ring oxidation" leads to the formation of alkylating mustard via several steps. A second metabolic pathway produces the cytostatically inactive metabolites 2- and 3-dechloroethyl-ifosfamide (2-d- and 3-d-ifo). The urinary excretion of the optical isomers of unmetabolised ifo and of 2- and 3-d-ifo, which represents the amount of ifo that has not been activated, was investigated by capillary gas chromatography for 18 treatment cycles in 14 children on various therapeutic schedules. The total cumulative excretion in 12 completely sampled cycles ranged from 27% to 50% of the ifo dose. Between 14% and 34% of the dose could be detected as ifo; 9% to 29%, as 3-d-ifo; and 2% to 8%, as 2-d-ifo. At 24 h after the end of therapy, excretion was nearly complete. Without exception, slightly more R-ifo (53%-61%) than S-ifo was excreted. S-2-d-ifo (50%-73%) was the main 2-d-metabolite. S-3-d-ifo (deriving from R-ifo) predominated in 6 of 14 children and R-3-d-ifo, in 8. Enantiomer-specific excretion increased after the end of infusion (up to 73% for R-ifo and 27% for S-ifo). We demonstrated stereospecific metabolism of ifo in children, with two different patterns of side-chain oxidation being observed. There was no evidence of important stereospecific ring oxidation in most children. A benefit should not be expected from the therapeutic application of pure enantiomers.

Adolescent↗
PubMed1991

A simple isocratic ion-pair high-performance liquid chromatographic determination of 1-beta-D-arabinofuranosylcytosine 5'-triphosphate for intracellular drug-monitoring and in vitro incubation assays.

A sensitive isocratic ion-pair HPLC method using a reversed-phase C18 column and phosphate buffer at pH 6 for the determination of the cytotoxic intracellular anabolite 1-beta-D-arabinofuranosylcytosine-triphosphate (Ara-CTP) of the antineoplastic drug cytarabine in leukaemic cells in vivo is described. Simultaneous determination of the physiological nucleotide deoxycytidine-triphosphate is possible. The recovery from cells is greater than 90%, the limit of detection is 25 ng ml-1 (51 nM l-1) and about 10 pM mg-1 cell protein. Extraction procedure and pitfalls are discussed. The method enables intracellular drug monitoring of Ara-CTP with standard HPLC equipment.

Arabinofuranosylcytosine Triphosphate↗
PubMed1989

Vitamin K-dependent coagulation parameters during the first six days of life: incidence of PIVKA II in newborns.

The vitamin K-dependent carboxylation of the prothrombin precursor PIVKA II (protein induced by vitamin K absence analogous to Factor II) is essential for the synthesis of prothrombin. The noncarboxylated precursor is found in peripheral blood in the presence of vitamin K deficiency. In this study prothrombin time, Factor II and Factor VII activity, and PIVKA II were investigated in 57 newborns without vitamin K prophylaxis in order to assess their vitamin K status. Two-dimensional immunoelectrophoresis demonstrated the presence of PIVKA II in 21% of the newborns, predominantly on the second day. The PIVKA-II positive group showed significantly lower prothrombin times than the PIVKA II-negative group. An oral dose of 3 mg vitamin K (Konakion) was administered to 35 healthy newborns in a second group with the first feeding. On the second day of life, these infants showed significantly higher vitamin K-dependent laboratory parameters than the group not given vitamin K; only 9% of the treated infants were positive for PIVKA II.

Biomarkers↗
PubMedDate not supplied

[Improved treatment results in children with AML: Results of study AML-BFM 93].

BACKGROUND: In the multicenter trial AML-BFM 93 daunorubicin or idarubicin was randomly applied in all patients during induction in combination with cytarabine and etoposide. After induction all patients were stratified to the standard or high risk group. To improve outcome in high risk patients high dose cytarabine and mitoxantrone (HAM) was introduced. The placing of HAM as either the 2nd or 3rd therapy block was randomized to evaluate the efficacy and toxicity accordingly. PATIENTS AND METHODS: 471 children with de novo AML entered the trial AML-BFM 93 (161 standard risk, 310 high risk). RESULTS: Overall, 387 of 471 (82 %) patients achieved remission, 5-year survival, event free survival (EFS), and disease free survival were 60 % SE 3 %, 51 % SE 2 % and 62 % SE 3 %, respectively. Idarubicin-based induction resulted in a significantly better blast cell reduction in the bone marrow on day 15 (25 of 144=17 % patients with > 5 % blasts compared to 46 of 149=31 % patients after daunorubicin, pchi(2)=0.01). This was, however, mainly seen in high risk patients treated with idarubicin (19 % vs. 38 %, pchi(2)=0.007). Cardiotoxicity, WHO grade 1 - 3 shortening fraction reduction after induction occurred in 6 % patients in both arms. In the total group of patients probabilities of five years event-free survival and disease-free survival were similar for patients treated with daunorubicin or idarubicin. However, in patients presenting with more than 5 % blasts on day 15 there was a trend for a better outcome after treatment with idarubicin (p logrank 0.06). Outcome in high risk patients was superior in study 93 compared to study 87 (remission rate and 5-year pEFS in study AML-BFM 93 vs. study 87: 78 % vs. 68 %, p=0.007, and 44 % vs. 31 %, p logrank=0.01). The placing of HAM as the 2nd or 3rd therapy block was of minor importance. However, patients who received the daunorubicin treatment during induction benefited from early HAM. CONCLUSION: Compared to study AML-BFM 87 treatment results in study AML 93 improved significantly in high risk patients. This can partly be contributed to the better response on day 15 after idarubicin induction but is mainly due to the introduction of HAM.

Acute Disease↗
PubMedDate not supplied

Meeting report: pharmacology in pediatric oncology. Summary of the 10th international expert meeting of the Kind Philipp Foundation for leukemia research, June 10 - 13, 2001 at the Schloss Reisensburg, Günzburg an der donau.

The Kind-Philipp foundation invited a group of international experts from academia, industry, and regulatory institutions to discuss aspects of new drug development in pediatric oncology. The current design, conduct and infrastructure of clinical trials in Europe and the United States, recent regulatory changes of drug development, and the impact of the likely availability of more targeted anti-cancer agents on drug development for pediatric cancers were discussed. This included a review of risk factors, surrogate markers, novel targets, and new anti-cancer agents for pediatric cancers. A special effort was made to define the requirements of well performed clinical trials, including target evaluation, trial design, use of pharmacokinetic (PK) studies, surrogate markers, ethical, and statistical aspects. The greater need for collaboration beyond the National level was recognized.

Child↗
PubMedDate not supplied

[Liposomal daunorubicine combined with cytarabine in the treatment of relapsed/refractory acute myeloid leukemia in children].

BACKGROUND: First-line treatment in AML commonly included high cumulative doses of anthracyclines with an increasing risk of cardiotoxicity. Liposomal daunorubicin (L-DNR) is thought to be less cardiotoxic without impairment of efficacy. METHODS: The AML-BFM REZ 97 study included two reinduction blocks with L-DNR (2 x 60 mg/m (2) n = 38, since 2/1999 3 x 60 mg/m (2) n = 31) combined with cytarabine (500 mg/m (2) 4 d). Children who achieved a second blast clearance were allocated to allogeneic stem cell transplantation either from a matched related (MRD) or a matched unrelated donor (MUD). Lack of a donor justified haploidentical SCT in early relapse (1st remission < 1 year) and autologous SCT in late relapse. PATIENTS: Between 1/1997 and 9/2001, 69 children were enrolled in the AML-BFM 97 relapse study. The median duration of first remission was 0.9 years. Forty-one patients had a remission of less than one year, 28 of more than a year. RESULTS: 46 children (67 %) achieved a second remission, defined as clearance of blasts in bone marrow and at least a partial hematological reconstitution. Seventeen of these children are alive (12 of 25 children receiving allogeneic SCT (MFD/MUD); 1 of 8 children after haploidentical SCT; 1 of 4 patients after autologous SCT and 3 of 9 patients treated with chemotherapy only). Further three children without 2nd remission survived after MFD-SCT (n = 2) or chemotherapy (n = 1; follow-up 0.3 to 0.7 years). Duration of first remission remains a significant prognostic factor. The pharmacokinetic investigation showed a high overall AUC of 234.6 mg/l h at a dose of 60 mg/m (2), and a volume of distribution of 1.98 l/m (2), which is much lower in comparison to conventional Daunorubicin. Regarding toxicity, the combination of L-DNR and cytarabine followed by SCT was feasible in experienced centers, however, acute complications like infection or septicemia in aplasia, mucositis and GvHD were common. By contrast, no clinical relevant cardiotoxicity was seen so far, but definitive results in long-term cardiotoxicity await a longer follow-up. In conclusion, L-DNR/cytarabine treatment induced a 2nd remission in most of the children with relapsed or refractory AML. It has to be followed by allogeneic SCT which enables long-term survival.

Adolescent↗
PubMedDate not supplied

[Pharmacokinetics of etoposide short-term infusions within the scope of the GPOH therapy protocol].

Important interpatient variability of etoposide pharmacokinetics during continuous infusion has been reported and drug level targeting, therefore, been suggested. The current German therapeutic protocols are mainly based on short-term infusion. We determined pharmacokinetic parameters during short-term infusion in 18 children aged between 10/12 and 17 years on different therapeutic schedules in order to investigate interpatient variability. The dosages ranged from 66 to 200 mg/m2. In the subgroup of patients who received 150 mg/m2 (n = 10) the AUC was 106 +/- 15 micrograms.h/ml (range 82-139), clearance 24 +/- 3 ml/min/m2 (18-31), t1/2 3.5 +/- 0.4. To compare kinetic data of all 21 courses in 18 children, standard AUC was calculated (AUC/100 mg/m2). The AUC then was (68 +/- 17 micrograms.h/ml)/(100 mg/m2). Half-life was 3.3 +/- 0.7 h and total clearance 26 +/- 6 ml/min/m2, respectively. In 5 courses in children < 2 years (< 10 kg), pharmacokinetic parameters were within the normal range. In this group dosage was calculated per kg. Dose reduction of 31% (mean) resulted in 22% (mean) lower AUC's. In conclusion, interpatient variability of etoposide pharmacokinetics during short-term infusion is limited. Dose reduction in children < 2 years is not substantiated by our pharmacokinetic data.

Adolescent↗
PubMedDate not supplied

[Is the pharmacokinetic profile of cytarabine clinically relevant?].

Cytarabine (Ara-C) is a cytotoxic agent which is rapidly metabolized and thus has a short half-life. Consequently, variations of infusion time influence directly the plasma level over time. Individual differences in plasma level courses with identical dosage are irrelevant regarding treatment response. Several studies, however, reported correlation of the leukemic cells' ability to build and retain the metabolite Ara-C-triphosphate (Ara-CTP) intracellularly with clinical response to therapy. The half-life of the intracellular Ara-CTP concentration in myelogenic blasts (AML) is lower than in blasts from children with acute lymphoblastic leukemia (common-ALL). The varying dosage recommendations of conventional (CD), intermediate (ID) and high-dose (HD) Ara-C therapy are based on considerations of cellular pharmacology. ID and HD Ara-C therapy schedules are designed to overcome well-known resistance phenomena thus providing high intracellular Ara-CTP concentrations.

Child↗
PubMedDate not supplied

[Ifosfamide and the metabolites of side chain oxidation--excretion in urine in various pediatric therapeutic protocols].

The precondition for the antineoplastic effect of ifosfamide (Ifo) is the oxydation of the oxazaphosphorine ring system. The 'ring oxidation' by several steps leads to the formation of alkylating mustard. A second metabolic pathway results in the cytostatically inactive metabolites 2- and 3-deschlorethyl-ifosfamide (2-, and 3-d-Ifo). This 'side chain oxidation' plays a quantitatively more important role with ifosfamide than with cyclophosphamide. The urinary excretion of unmetabolized Ifo and of 2- and 3-d-Ifo, which represents the amount of Ifo not activated, has been investigated by capillary gaschromatography in 18 treatment cycles of 14 children with various therapeutic schedules (800, 2000 and 3000 mg/m2 given as bolus, over 1 h or as continuous infusion for 2 respectively 5 days). The total cumulative excretion during 12 completely sampled cycles ranged from 27 to 50% of the given Ifo. Between 14 and 34% could be detected as IFO, 9 to 29% as 3-d-Ifo and 2 to 8% as 2-d-Ifo. In 4 children the amount of 'side chain oxidized' IFO exceeded the amount of unmetabolized Ifo. 24 hours after the end of therapy excretion is nearly complete. No relationship between the excreted amount of unmetabolized Ifo, 2-d-Ifo and 3-d-Ifo and the dose schedule could be determined. There was no clearcut dependency between cumulative dose, the children got in the past, and formation of 2- and 3-d-metabolites.

Adolescent↗
PubMedDate not supplied

[Effect of etamsylate on hemorrhagic diathesis of children with oncologic diseases. Retrospective matched-pair analysis of 64 patients in a study of 100 patients of the Münster University Pediatric Clinic].

The hemostatic efficacy of ethamsylate studied by a matched-pair analysis was not proved to be statistically significant. The appearance of bleeding signs as well as the frequency of platelet transfusions have been examined. An important side-effect was found in patients receiving ethamsylate: severe leucocytopenia (less than 1000 leucocytes/microliters) was noticed more frequently followed by an enhanced susceptibility to infections. The incidence of septic infections was proved to be significantly increased in an extended sample of 100 patients.

Blood Coagulation Tests↗
PubMedDate not supplied

[Antiinfectious prophylaxis in pediatric oncology. Work group "Quality Assurance" of Society for Pediatric Oncology and Hematology (GPOH)].

Infections in disease- and/or chemotherapy-related neutropenia are major, often emergency-type problems in the treatment of pediatric oncology patients and explain the ongoing discussion about antiinfectious prophylaxis. The different aspects of prophylaxis and an overview on the literature are presented. Antiinfectious prophylaxis in pediatric oncology includes the following issues: 1. General aspects such as information for patients and parents on neutropenia and risk of infectious diseases and indication and management of reverse isolation and barrier isolation; 2. antibacterial prophylaxis with oral non-absorbable and oral absorbable antibiotics; 3. Pneumocystis carinii (Pc) prophylaxis; 4. antifungal prophylaxis to prevent disseminated candidiasis and aspergillosis; 5. antiviral prophylaxis, especially varicella-zoster-virus (VZV) post-exposure prophylaxis and cytomegalovirus (CMV) prophylaxis; 6. immunoglobulins and hematopoietic growth-factors (HGF); 7. active immunization. An evaluation of those measures leads to the following conclusions: A major controversy exists regarding antibacterial and antifungal prophylaxis. Probably not effective are the use of reverse isolation and of oral, non-absorbable antibiotics. Oral absorbable antibiotics, antifungal prophylaxis using fluconazole and amphotericin B and the use of hematopoietic growth factors are likely to be effective. Clearly effective are strict hand-washing procedures, Pc and CMV prophylaxis and passive vaccination against VZV in case of VZV exposure of a seronegative patient.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

[Pharmacokinetic aspects of oral administration of etoposide].

BACKGROUND: Etoposide is a cytotoxic agent which is frequently employed in paediatric oncology and which is available for intravenous as well as oral application. Many advantages of the formulation for oral use have been opposed by concerns about its interindividually varying bioavailability. The influence of the dosage of etoposide on its activity and toxicity ("schedule dependency") has also been discussed. The present paper deals with the pharmacokinetics of oral etoposide focusing on the interindividual variability. PATIENTS: Sixteen patients aged between 3 and 73 years received oral etoposide at a dosage of 28 mg/m2 to 149 mg/m2 in combination with oral trofosfamide for palliation. METHOD: HPLC was used to measure total and free serum etoposide in 16 patients, and the etoposide concentration in several urine samples from 8 patients. Pharmacokinetic parameters were normalized to a dosage of 100 mg/m2. RESULTS: The peak serum concentration, the time to peak concentration, the area under the concentration-time curve, the terminal half-life and the apparent clearance after oral application were calculated to be 6.7 micrograms/ml, 2.1 h, 51.8 (microgram.h/ml)/(100 mg/m2), 5.6 h, and 40.3 ml/min for total etoposide, and 0.23 microgram/ml, 1.9 h, 1.76 (microgram.h/ml)/ (100 mg/m2), 5.9 h, and 1172 ml/min for free serum etoposide, respectively. On an average, urinary recovery of etoposide was 21% of the oral dose. The fraction of free etoposide was calculated to be close to 4%. Regarding the systemic exposure to etoposide, a variation coefficient of 40% was determined. Additional studies showed that the interindividual variability mainly concerned the peak levels, while the duration for which intermediate etoposide levels were maintained varied less between individuals. On simulating different dosage schedules, it was seen that the duration of intermediate concentrations (0.5-2 micrograms/ml) may be extended significantly by dividing the daily dose of etoposide into two oral applications. CONCLUSION: The total systemic exposure under oral etoposide treatment varies considerably between individuals. Extended intervals of intermediate etoposide concentration and less variation are, however, possible with oral therapy. Dividing the daily dose into two applications seems advisable. Future studies are warranted to test hypotheses on pharmacokinetic-pharmacodynamic aspects by pharmacological drug monitoring.

Administration, Oral↗
PubMedDate not supplied

[Prognosis of children with acute myelocytic leukemia after first relapse].

UNLABELLED: Nearly 40% of children treated within the AML BFM studies experience recurrence of their disease after having achieved remission. In our retrospective analysis we tried to estimate prognosis after relapse in children treated with intensive relapse regimens and studied the impact of prognostic factors for second remission and survival. PATIENTS: 102 patients suffering from first relapse were treated intensively according to the relapse protocols BFM REZ91 and REZ93 or intensive salvage therapy consisting of double induction with high dose Ara-C, mitoxantrone and VP-16. Once in CR, patients continued to receive a 6-week consolidation and either allogeneic or autologous bone marrow transplantation (BMT). RESULTS: Time to relapse was in median 1.1 years, range 0-8 years. Fifty-two of 102 pts. (51%) achieved 2nd remission (CR), 10 (10%) partial remission, 37 (36%) were nonresponders, and 3(3%) died early during salvage therapy. Twenty-seven were still in CR, median 2.5 years, range 0.4-7.0 years, with an overall survival of 21%, SE 5% after 5 years. The response and survival rate was similar in all treatment groups. Fifty patients were transplanted, 43 being in 2nd CR, and 7 with residual blasts. Twenty-seven patients received an allograft: Twenty-one from a matched sibling (MSD), 1 from a haploid and 5 from a matched unrelated donor (MUD); 23 received an autograft. None of the patients transplanted in partial remission survived. Whereas 7 of 16 patients were alive after MSD in 2nd CR, 1 after haploid BMT. Four of 5 patients died after MUD BMT. Multivariate risk factor analysis revealed duration until relapse to be the most important factor for survival after relapse. The maximum risk-ratio was obtained at a threshold value of 1.5 years after diagnosis resulting in a 5-year survival of 10%, SE 5% for early relapse, and 40%, SE 10% for late relapse, p logrank 0.0001. CONCLUSION: Intensive relapse regimens can induce a 2nd CR in half of the patients. Children with late relapse (> 1.5 years after diagnosis) have a realistic chance for longtime survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

[Intracellular retention of cytarabine-triphosphate (Ara-CTP) in blasts of children with acute lymphoblastic leukemia. Correlation with clinical course parameters].

BACKGROUND: Cellular uptake and intracellular phosphorylation to the nucleotide cytosine arabinoside-triphosphate (Ara-CTP) is the precondition for the cytostatic effect of cytarabine. The pharmacokinetics of Ara-CTP in leukemic cells was reported to be of clinical importance in adult nonlymphoblastic leukemia. Therefore, the role of intracellular Ara-CTP formation and retention was investigated in blast cells from children with acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: At the time of diagnosis, peripheral or bone marrow blast cells from 41 children with ALL and 13 with relapsed ALL were incubated in Ara-C containing medium (1 hour, 1 or 3 micrograms/ml) followed by reincubation in Ara-C free medium (3 h). Intracellular Ara CTP formation and Ara-CTP retention were determined. MAIN RESULTS: Ara-CTP formation did not show marked differences between the different immunological subtypes. Ara-CTP retention, however, was significantly lower in T-ALL (37 +/- 15%, n = 8) compared to non-T-ALL (67 +/- 25%, n = 33; p < 0.003). Ara-CTP retention was also significantly different in children with and without persistence of peripheral blast cells after one week of prednison treatment (71 +/- 30%, n = 9 and 53 +/- 19%, n = 21; p = 0.031) as well as in children with and without complete bone marrow remission on day 15 of the ALL-BFM treatment protocol (66 +/- 17%, n = 19 and 43 +/- 18%, n = 11; p = 0.018). Ara-CTP retention was inversely correlated with the risk groups defined by the ALL-BFM treatment protocols (standard 79 +/- 29, intermediate 59 +/- 25, high risk 47 +/- 21%). A trend towards lower Ara-CTP retention was observed in relapsed leukemias (relapsed non-T-ALL 51 +/- 17%, p = 0.061). The difference in the probability of event free survival (following risk group adapted treatment according to ALL-BFM trials) between children with high (> or = 72%; 0.92 +/- 0.08) and low (< 72%: 0.58 +/- 0.15) Ara-CTP retention up to now did not reach statistical significance (p = 0.12). CONCLUSIONS: The more rapid decrease of cellular Ara-CTP in T-cell leukemia and children at higher clinical risk groups provide a pharmacokinetic rationale for prolonged infusion duration as an alternative to the intensification by dose escalation alone.

Adolescent↗
PubMedDate not supplied

[HIT-GBM: multicenter study of treatment of children with malignant glioma].

The German society for paediatric oncology and hematology starts a clinical study for the treatment of children with glioblastoma, multifocal astrocytoma grade 3, brain stem grade 3 astrocytoma and typical diffuse ponsglioma. Conventional fractionated radiotherapy (54 Gy) will follow surgery. Simultaneously an additional experimental treatment will be given. The experimental treatment study will change every second year and starts with oral trofosfamide 100 mg/m2/d and VP16 25 mg/m2/d.

Antineoplastic Agents, Alkylating↗