Potential role of magnetic resonance spectroscopy in assessment of tumour response in childhood cancer.

This brief review considers to what extent Magnetic Resonance Spectroscopy (MRS) can play a role in monitoring early tumour response with examples of preclinical studies and selected clinical studies in tumours of children and young adults. An early non-invasive indicator of tumour response to therapy would provide useful information regarding the effectiveness of therapy. This might be a relevant prognostic factor in new patients and in phase II studies could facilitate recommendations at an early stage as to whether to continue treatment. This review suggests that several markers and ratios are emerging as potential prognostic markers, but larger prospective studies are needed before translating this into clinical practice.

Autologous bone marrow transplantation for childhood acute lymphoblastic leukaemia in second remission - long-term follow-up.

From 1984 to 1996, 31 consecutive children without sibling donors, aged 5-19 years (median 8) with acute lymphoblastic leukaemia (ALL) in second complete remission (CR), received unpurged autologous bone marrow transplantation (ABMT) after melphalan and single fraction total body irradiation (TBI). ABMT was performed using fresh unmanipulated marrow harvested after standard reinduction and consolidation therapy 2-11 months (median 5) after relapse. With a median survival of 2.9 years the probability of survival for all patients in continuing second CR was 45.1% (95% CI, 24%-62%) after 5 years. Regimen-related and non-leukaemia mortality was 7% (95% CI, 2%-26%). The longest time to second relapse from ABMT was 3.1 years. Pituitary and gonadal dysfunction requiring hormonal replacement therapy occurred in the majority of long-term survivors. Twelve patients developed cataracts. ABMT with melphalan/single fraction TBI has proved an effective anti-leukaemia treatment with low regimen-related mortality but significant long-term morbidity. The current approach of allogeneic BMT from an unrelated donor when no sibling donor is available, following conditioning with cyclophosphamide/ fractionated TBI has resulted in a reduced relapse rate and improved short-term overall survival in the treatment of relapsed childhood ALL. However, long-term results are awaited.

Survival of childhood acute lymphoblastic leukemia: results of therapy at Tata Memorial Hospital, Bombay, India.

The purpose of this study was to analyze the outcome of patients who completed therapy for acute lymphoblastic leukemia (ALL) and to study the role of an aggressive induction regimen in preventing post therapy relapses. Four hundred and twenty-two patients with ALL who completed therapy during the period 1975-1991 were followed. Two hundred and sixty patients received the aggressive MCP 841 protocol and 162 patients received various other less aggressive treatment regimens. Patients were followed with periodic examination and complete blood counts. The incidence of post therapy relapse was 27% in the less aggressive protocols and 15% in the MCP 841 protocol (p = 0.001). An higher percentage of relapses was seen in males (p = 0.05) and 89% relapses occurred within two years of stopping therapy. The relapse rate after 5 years of cessation of therapy was 0.59%. In conclusion, aggressive induction therapy is the most crucial factor in predicting relapses following cessation of therapy in ALL patients. However, relapses are unlikely to occur five years post therapy.

Low incidence of CNS relapse with cranial radiotherapy and intrathecal methotrexate in acute lymphoblastic leukemia.

OBJECTIVES: To assess the incidence of isolated central nervous system (CNS) relapses in patients of acute lymphoblastic leukemia (ALL) treated with a protocol containing cranial irradiation and intrathecal methotrexate as CNS directed therapy. DESIGN: Prospective non randomized study. SETTING: Department of Medical Oncology, Tata Memorial Hospital. SUBJECTS: 623 children of ALL on MCP 841. METHODS: CNS relapse was diagnosed, if upon examination of the CSF, more than 50 cells/microliter were observed, or a count of 5 cells which were unequivocally lymphoblasts. RESULTS: The incidence of isolated CNS relapse was 1.75% with the use of this treatment. Age, sex, white blood cell count, platelet count, lactic dehydrogenase and immunophenotyping were not significantly related to isolated CNS relapse. CONCLUSION: A low incidence of isolated CNS relapse demonstrates the adequacy of the presymptomatic CNS therapy.

Evaluation of 31P high-resolution magic angle spinning of intact tissue samples.

The first detailed evaluation is presented of high-resolution (31)P MRS using magic angle spinning (MAS) of intact tissue samples and comparison with the conventional method of studying tissue extracts. The main motivation is that MAS leaves the sample intact at the end of the study for histopathological evaluation. While MAS of tissue samples has previously been demonstrated for (1)H MRS, (31)P MRS is better suited to study of the phospholipid metabolites of importance in cancer. Samples of rhabdomyosarcoma and RIF-1 experimental tumours were maintained at 4 degrees C, spun at 3 kHz and measured in 28-min acquisitions at 11.7 and 14 T. Metabolite stability was evaluated using four sequential 28-min acquisitions. High-resolution MRS was performed on extracts of the same tissue samples. (31)P HR-MAS yielded well-resolved high-resolution spectra, showing peaks from phosphoethanolamine (PE), phosphocholine (PC), inorganic phosphate, glycerophosphoethanolamine and glycerophosphocholine, with linewidths in the range 3-20 Hz. In tumour samples there was no significant change in peak areas over a 2-h period, while peaks sensitive to pH (inorganic phosphate, PE and PC) showed a small change in chemical shift, corresponding to a change of 0.13 +/- 0.06 pH units. Tissue metabolite concentrations showed good agreement with concentrations measured from extracts of the same pieces of tissue. For calculation of metabolite concentrations, the measurement of a reference compound in a separate measurement is more robust than using the signal from a reference compound in the rotor with the sample. Compared with performing tissue extracts, use of MAS of intact tissue samples requires less preparation, is quicker and permits the same sample to be used for subsequent histopathology. The methodology has particular application in studying phospholipid metabolism in cancer and in monitoring tumour response to treatment, where concentrations of phospholipid-related metabolites are found to alter following response to a wide range of anti-cancer therapies.

Response with combined modality treatment in childhood rhabdomyosarcoma.

Children diagnosed with rhabdomyosarcoma at the Tata Memorial Hospital during the period January 1986-December 1988 were studied. All were treated with combination chemotherapy incorporating vincristine, Adriamycin, and cyclophosphamide given sequentially in repeated cycles over 18 months, along with local radiotherapy. Of 24 patients, 18 patients had advanced-stage disease at onset. All patients have been followed up for 18 months or more. Of the 11 patients with group III disease, six are in complete remission; of the six patients with group IV disease, two patients are in complete remission. These results are clearly better than those achieved in the past, where surgery was employed as the primary modality of therapy with chemoradiotherapy given only for patients with group IV disease.