Enhancement of ACNU treatment of the BT4An rat glioma by local brain hyperthermia and intra-arterial drug administration.

To evaluate the role of intra-arterial (i.a.) chemotherapy, intravenous (i.v.) chemotherapy, and local brain hyperthermia in the treatment of gliomas, the effect of i.v. versus i.a. drug delivery, with or without local brain hyperthermia, was evaluated in BD IX rats with BT4An gliomas implanted in the right frontal lobe. The rats were given ACNU 18 mg/kg i.a. in the right carotid artery or i.v. in the inferior cava with or without local microwave hyperthermia at 42.4 degrees C for 45 min. ACNU i.v. alone had no notable effect on survival. Survival was prolonged when ACNU without hyperthermia was given i.a. instead of i.v. (P < 0.05). Thermochemotherapy with ACNU i.a. was more effective than with ACNU i.v. (P < 0.01). Survival improved as hyperthermia enhanced the i.v. drug effect (P < 0.01), and hyperthermia also improved the i.a. ACNU effect (P < 0.01). Post-treatment survival was more than doubled for the group given combined i.a. ACNU and hyperthermia, compared to controls. Thermochemotherapy, particularly with i.a. drug administration, seems to be a promising new approach for the treatment of primary brain tumours. However, more knowledge about tolerance of human brain tissue to hyperthermia is necessary before this treatment modality is used in patients with a reasonable life expectancy.

Thermochemotherapy with cisplatin or carboplatin in the BT4 rat glioma in vitro and in vivo.

The effect of thermochemotherapy with cisplatin or carboplatin was compared in the BT4-cell line. In vitro: BT4C-cells were treated with different concentrations of cisplatin or carboplatin, with or without simultaneous hyperthermia. In vivo: Inbred BD IX rats with transplanted glioma-like BT4A or glioblastoma-like BT4An tumors on the hind leg were treated with cisplatin (4 mg/kg) or carboplatin (50 mg/kg), with or without local hyperthermia. In vitro the benefit of adding hyperthermia to chemotherapy was similar for cisplatin and carboplatin. For both cisplatin and carboplatin, the difference of treatment effect between thermochemotherapy and chemotherapy alone increased with higher drug concentrations. In vivo hyperthermia clearly enhanced the effect of carboplatin on BT4A tumors. When treating BT4An tumors, thermochemotherapy with cisplatin or carboplatin was equally effective. Both combinations were superior to treatment with hyperthermia alone. Local toxicity and weight loss following thermochemotherapy were comparable when substituting cisplatin with carboplatin.

Timing of hypertonic glucose and thermochemotherapy with 1-(4-amino-2-methylpyrimidine-5-yl) methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU) in the BT4An rat glioma: relation to intratumoral pH reduction and circulatory changes after glucose supply.

PURPOSE: Intraperitoneal hypertonic glucose has previously been shown to induce hyperglycemia, hemo-concentration, and to influence systemic and tumor circulation, and, thus, enhance the effect of thermochemotherapy with 1-(4-amino-2-methylpyrimidine-5-yl)methyl-3-(2-chloroethyl)-3-nitrosoure a (ACNU) and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). However, the optimal timing and the precise mechanisms responsible are not known. The effect of different time intervals between glucose load and thermochemotherapy with ACNU in the treatment of BT4An tumors, therefore, was investigated. Changes of serum glucose (Se-glucose), hemoglobin, systemic circulation parameters, tumor pH, and tumor temperature, induced by intraperitoneal glucose and/or hyperthermia, were measured to assess their effect on tumor growth. METHODS AND MATERIALS: (a): Inbred BD IX rats with BT4An tumors on the hind leg were treated with ACNU 7 mg/kg intravenously just before waterbath hyperthermia, and intraperitoneal hypertonic glucose (6 g/kg) at different time intervals before (240-0 min) or immediately after thermochemotherapy. (b): Intratumoral pH and temperature were measured at different intervals after intraperitoneal glucose, and during hyperthermia with or without previous glucose. (c): Hemoglobin, hematocrit, and Se-glucose were measured at different times after intraperitoneal glucose. (d): Mean arterial pressure, pulse pressure, and heart rate were measured for 120 min after intraperitoneal glucose. RESULTS: (a): The number of tumor controls and the growth delay was greatest with glucose 45 min before thermochemotherapy, and least with a time interval of 240 min. Glucose after thermochemotherapy delayed tumor growth. (b): After intraperitoneal glucose alone, intratumoral pH decreased gradually from 6.76 to 5.86 after 240 min. Hyperthermia 120 min after glucose induced a rapid further pH drop, while hyperthermia alone had no significant influence on pH. Intratumoral temperature was higher during hyperthermia in animals given glucose. (c): A substantial rise of Se-glucose and hemoglobin developed. The hemoconcentration was maintained also after reduction of Se-glucose towards normal values. (d): An initial tachycardia, and a reduction of the mean arterial pressure of about 10% 5-45 min after was measured. CONCLUSION: The data indicate that a complex interaction between gradually reduced tumor pH, hyperglycemia, hemoconcentration, and reduced tumor blood flow, and not a breakdown of systemic circulation, is responsible for the effect of intraperitoneal glucose on thermochemotherapy with ACNU. Interestingly, enhancement of thermochemotherapy effect was also seen when intraperitoneal glucose was given after heat and ACNU.

The new tubulin-inhibitor combretastatin A-4 enhances thermal damage in the BT4An rat glioma.

PURPOSE: To investigate the toxicity of combretastatin A-4 disodium phosphate (CA-4) and its vascular effects in the subcutaneous (s.c.) BT4An rat glioma, and additionally, to determine the tumor response of CA-4 combined with hyperthermia. METHODS AND MATERIALS: For assessment of drug toxicity, rats were given 50, 75, or 100 mg/kg CA-4 and followed by daily registration of weight and side effects. Interstitial tumor blood flow was determined by laser Doppler flowmetry in rats injected with 50 mg/kg CA-4. In the tumor response study we administered CA-4 50 mg/kg alone or combined with hyperthermia (waterbath 44 degrees C for 60 min) 0 or 3 h later. RESULTS: We found that CA-4, at a well-tolerated dose of 50 mg/kg, induced a considerable time-dependent decrease in the tumor blood flow. Tumor blood flow was reduced by 47-55% during the first 110 min after injecting CA-4, and thereafter remained decreased until the measurements were terminated. Administering CA-4 3 h before hyperthermia yielded the best tumor response and increased tumor growth time significantly compared with simultaneous administration of CA-4 and hyperthermia (p = 0.03). Interestingly, CA-4 alone did not influence tumor growth. CONCLUSION: CA-4 induces a gradual reduction in tumor blood flow which can be exploited to sensitize the BT4An tumor for hyperthermia.

A thermometry system for quality assurance and documentation of whole body hyperthermia procedures.

Since December 2001, the Department of Oncology and Medical Physics, Haukeland University Hospital, Norway has been conducting whole body hyperthermia (WBH) studies, treating patients with either ovarian carcinoma or non-Hodgkin lymphomas. Accurate and reliable thermometry instrumentation is important in all types of hyperthermia procedures, particularly in WBH, where the target patient body temperature is 41.8 degrees C. Reliable documentation of side-effects in clinical studies is also dependent on precise temperature monitoring, since in this temperature range even small, but systematic, inaccuracies (0.1-0.2 degrees C) in the temperature monitoring is expected to affect the amount of side effects. Readily available heating and temperature data from previous treatment sessions of the same patient is also valuable for precise temperature control in future treatment sessions. The WBH thermometry system implemented at Haukeland University Hospital is described. It is based on commercially available components, including standard medical thermistor probes, and includes a temperature calibration and verification facility. The thermometry system is accurate, reliable, easy to use, comfortable for the patient and relatively inexpensive. By implementing the Steinhart-Hart polynomial fit to standard medical thermistor probe data, it is shown that the WBH treatment thermometers used can measure the patient body temperatures with a short- and long-term accuracy of +/- 0.01 degrees C.

Thermal enhancement of ACNU and potentiation of thermochemotherapy with ACNU by hypertonic glucose in the BT4An rat glioma.

Hyperthermia increases the cytotoxicity of the nitrosourea BCNU (carmustine). Glucose given before treatment may further increase the value of thermochemotherapy, presumably by lowering tumour pH through blood flow reduction. The water-soluble ACNU (nimustine) is an alternative to other nitrosoureas in the treatment of gliomas. The drug is soluble without use of ethanol, and the eye complications when given intra-arterially are reduced compared with similar use of BCNU. The influence of simultaneous hyperthermia on treatment with ACNU, and the value of glucose administered before thermochemotherapy therefore were investigated in the malignant rat glioma BT4An. BD IX rats with subcutaneous BT4An tumours on the hind leg were treated with ACNU (i.p.), or ACNU and locally applied waterbath hyperthermia (44 degrees C for 45 min), with or without previous glucose (6 g/kg i.p. 2 hours before treatment). ACNU (10 or 20 mg/kg) alone and ACNU (20 mg/kg) after previous glucose did not influence tumour growth, compared to the controls. Simultaneous ACNU (10 mg/kg) and hyperthermia clearly was more effective than treatment with hyperthermia alone. Glucose load before treatment further enhanced the effect of combined ACNU and hyperthermia. Glucose before treatment did not change local toxicity or weight profiles of treatment with ACNU alone, or simultaneous ACNU and hyperthermia. Glucose load therefore represented a therapeutic gain when administered before thermochemotherapy with ACNU.

Effect of hypertonic glucose in thermotolerant rat BT4An gliomas treated with combined hyperthermia and BCNU in vivo.

The influence of hypertonic glucose i.p. on development of thermotolerance and thermochemosensitivity with BCNU in thermotolerant tumours, and on intratumoural pH alterations in previously unheated and thermotolerant tumours, was investigated in BT4An tumours grown on the hind foot of BD IX rats. Thermotolerance was induced with local waterbath hyperthermia (44 degrees C/45 min) 24 h before start of test treatment. Hypertonic glucose immediately after priming hyperthermia did not inhibit development of thermotolerance, despite a significant reduction of pH by glucose. The pH reduction was less in thermotolerant tumours. Glucose administered before treatment of thermotolerant tumours did not change the growth rate of tumours treated with hyperthermia (44 degrees C/45 min), BCNU (20 or 25 mg/kg i.p.) or thermochemotherapy with a low or high dose BCNU (10 or 20 mg/kg), in contrast to previous results, where glucose enhanced thermochemosensitivity of non-thermotolerant tumours.

Potentiation of combined BCNU and hyperthermia by pH reduction in vitro and hypertonic glucose in vivo in the BT4 rat glioma.

In vitro studies have shown enhanced cell killing of BCNU and hyperthermia at acutely lowered pH. In animals hypertonic glucose i.p. has repeatedly been demonstrated to reduce intratumoral pH. Effect of hyperthermia (43 degrees C for 45 min), or BCNU (3.33 micrograms/ml or both on BT4C cells were investigated in vitro, with pH 7.5, 7.0 and 6.5 in the medium during treatment. The effect of elevated glucose concentration in the medium (20 mmol/l) during treatment with hyperthermia, or BCNU, or both, was also investigated at pH 7.5. BD IX rats with transplanted BT4A or BT4An tumours on the hind foot were treated with BCNU i.p., locally applied water bath hyperthermia (44 degrees C for 45 min) or both, with or without previous glucose (6 g/kg i.p. 2 h before treatment). In vitro: low pH markedly increased cell killing by combined BCNU and hyperthermia, but pH had only a minor influence on treatment with BCNU or hyperthermia alone. Increased glucose concentration in the medium did not influence the effect of BCNU alone, hyperthermia alone, or BCNU and hyperthermia. In vivo: glucose reduced the effect of BCNU alone on BT4A tumours, but did not influence the treatment results with hyperthermia alone. However, glucose enhanced the effect of combined BCNU and hyperthermias. The effect on BT4An tumours of BCNU or hyperthermia alone were not affected by glucose, but glucose markedly enhanced the tumour effect of combined BCNU and hyperthermia. Hyperglycaemia seems to be a promising method to increase the benefit of combined hyperthermia and BCNU. However, glucose-induced altered tumour circulation could hamper the potential benefit by decreased drug uptake.

[Half-body irradiation. An effective palliative treatment of widespread skeletal metastases]. / Halvkroppsbestråling. En effektivt lindrende behandling ved utbredte skjelettmetastaser.

In a large number of cancer patients, extensive skeletal metastases or myelomatosis induce vast suffering, such as intolerable pain and local complications of neoplastic bone destruction. Analgetic drugs frequently do not yield sufficient palliation. Irradiation of local fields often has to be repeated, because of tumour growth outside previously irradiated volumes. Wide field irradiation of the lower or upper half of the body causes significant relief of pain in most patients. Adequate pretreatment handling of patients, method of irradiation, and follow-up are of marked importance to reduce side effects, and are described as they are carried out at the Department of Oncology, Haukeland Hospital.

Hyperthermia improves local tumour control in locally advanced breast cancer.

We report three patients with advanced breast cancer who received hyperthermia (43 degrees C over 1 h, weekly x 4) and radiotherapy as palliative treatment for chest-wall recurrence. The case reports demonstrate situations where hyperthermia may be beneficial. These include tumours where radiotherapy alone is not expected to achieve control, such as large fungating tumours, and in previously irradiated areas. In these patients, hyperthermia with radiation achieves better local control of the tumour and delays the need for systemic chemotherapy. This may improve the quality of palliation.

Interaction between microwave-induced brain hyperthermia and high dose rate radiation in the BT4 An brain glioma in rats.

The cerebral BT4An glioma model in BD IX rats was used to study the effect of hyperthermia given in combination with radiotherapy (thermoradiotherapy) in the treatment of brain tumours. A single treatment with high dose rate radiation was given to a local brain field. Local brain hyperthermia was given at 42.4 degrees C for 45 min by externally applied microwaves (700 MHz), immediately before radiotherapy (10 Gy). In a pilot study, thermoradiotherapy increased the median life span with 20 days compared to controls, which was significantly better than that observed after radiotherapy alone (7 days). In an extended experiment the corresponding figures for thermoradiotherapy, hyperthermia alone and radiotherapy alone were 12.5, 3.5, and 3.5 days, respectively. Thermoradiotherapy was significantly better than radiotherapy and hyperthermia alone. There was no acute mortality in these experiments. Neurological side-effects were infrequent, of slight degree and reversible. The present study shows that a survival benefit of adding hyperthermia to radiotherapy can be achieved without unacceptable neurological side-effects in an animal glioma model.

A cerebral glioma model for experimental therapy and in vivo invasion studies in syngeneic BD IX rats.

An in vivo glioma model was developed in syngeneic BD IX rats. The BT4An tumor was derived from serial in vivo passages of the BT4A tumor, originally induced from transformed fetal rat brain cells after transplacental exposure to ethylnitrosourea. The cell line was characterized for the presence of neuroglial differentiation markers, chromosome content and cell cycle distribution as determined by flowcytometry. A standardized method for i.c. tumor induction was developed, and the tumors were investigated by light and electron microscopy and for evidence of blood-brain barrier disruption. Tumor cell ability for phagocytosis was studied, as this property may be important for the invasion pattern of the tumors. We conclude that the model seems suitable for both in vivo therapy and invasion studies. The tumor had 100% tumor take, yielded a predictable symptom-free life span after inoculation, had a characteristic histological picture of an aggressive glioma, and the blood-brain barrier within the tumor was in part disrupted. Compared to the parent cell line, there was loss of neuroglial differentiation markers, the chromosomal distribution was changed, and the ability for phagocytosis was practically lost.

Flow cytometric assessment of peripheral blood contamination and proliferative activity of human bone marrow cell populations.

Bone marrow aspiration is superior to bone marrow biopsies due to less discomfort to the volunteer or patient, but it is inferior concerning the reproducibility of cytokinetic information. Therefore, a method that could select aspirates of quality and reproducibility equal to those of biopsies was sought. Low-density (mononucleated) bone marrow cells were labelled with T200 common leukocyte antigen, CD45, which differentiate cells into erythroid, myeloid, and lymphocyte + monocyte subpopulations based on their immunofluorescence intensity. A hypotonic propidium iodide solution was added, and DNA cell cycle characteristics of the total cells and the subpopulations were obtained. Twenty-two aspirations were performed on three healthy men. There was a strong negative correlation between the amount of CD45-gated lymphocytes + monocytes, indicative of peripheral blood cell contamination in the aspirate, and the percentage of total cells and subpopulations in DNA S phase. A marked reduction in the percentage of cells in S phase was observed when the lymphocyte + monocyte counts were higher than 30%; this level was used to exclude aspirates with an unacceptable degree of peripheral blood cell admixture. Twelve of the aspirates were found to be of acceptable quality due to their low lymphocyte + monocyte count. These aspirates were compared with 11 bone marrow biopsy expellates from hematologically normal patients undergoing open cardiac surgery. The 12 aspirates were found to have almost identical mean percent S-phase cells as the biopsy expellates, both for the total cell population (14% +/- 3.45% vs. 15% +/- 1.5%) and for the erythroid (24% +/- 6% vs. 24.4% +/- 3.3%) and myeloid (10% +/- 2.4% vs. 10.7% +/- 2.5%) subpopulations.(ABSTRACT TRUNCATED AT 250 WORDS)