Phase I evaluation of preirradiation chemotherapy with carmustine and cisplatin and accelerated radiation therapy in patients with high-grade gliomas

OBJECTIVE

A Phase I study was conducted to determine the safety, toxicity, and maximum tolerated dose of preirradiation chemotherapy using carmustine (BCNU) and cisplatin in the treatment of high-grade gliomas.

METHODS

Patients with newly diagnosed high-grade gliomas received BCNU and cisplatin after surgery, both before and during definitive radiation therapy. Preirradiation chemotherapy consisted of an administration of 40 mg/m2 BCNU on Days 1 through 3 and 30 mg/m2 cisplatin on Days 1 through 3 and 29 through 31 and repeated at 8 weeks to coincide with the start of radiation therapy. Postradiation chemotherapy consisted of an administration of 200 mg/m2 BCNU once every 8 weeks for four cycles. Radiation therapy consisted of 160-cGy fractions administered twice daily for 15 days, yielding a total dose of 4800 cGy. Dose escalation of BCNU was planned. If hematological toxicity was mild, the dose of cisplatin was to be held constant and BCNU dose escalated to 50 mg/m2 on Days 1 through 3.

RESULTS

Eighteen patients were studied. The hematological toxicity was dose-limiting. Grade 3 or 4 leukopenia occurred in each of 10 patients (56%), and Grade 3 or 4 thrombocytopenia occurred in each of 9 patients (50%). Other toxicities included anorexia (94%), nausea (83%), emesis (33%), alopecia (94%), mild ototoxicity (50%), and, in one patient, death as a result of BCNU pulmonary toxicity. The median survival time was 14 months. Objective responses occurred in 45% of the patients evaluable for response. The maximum tolerated dose of this combination was 50 mg/m2 BCNU on Days 1 through 3 and 30 mg/m2 cisplatin on Days 1 through 3 and 29 through 31 before radiation and repeated in 8 weeks to coincide with the start of radiation.

CONCLUSION

This schedule of the preirradiation administration of BCNU and cisplatin with accelerated hyper-fractionated radiation therapy for the treatment of high-grade gliomas provides a less toxic alternative to that of previous studies of preirradiation chemotherapy with these agents and merits further investigation.

Efficacy of radiotherapy for malignant gliomas in elderly patients

PURPOSE

Age above 65 years is a strong negative prognostic factor for survival in patients with malignant gliomas (MG) treated with radiotherapy (RT) and its value has been questioned. We analyzed the effect of RT on the survival of elderly patients with malignant gliomas.

METHODS AND MATERIALS

We examined 85 consecutive elderly patients with a histological diagnosis of MG. Age ranged from 65 to 81 years (median 70 years). Glioblastoma multiforme (GBM) was diagnosed in 64 patients (75.3%). Surgical treatment included needle biopsy in 32 patients (37.6%). Median postoperative Karnofsky Performance Status (KPS) was 60 (range: 30-100). Survival probability was estimated using Kaplan-Meier method and compared with the log-rank test. Crude and adjusted hazard ratios (HR) were calculated using Cox's regression models.

RESULTS

Median survival time for all patients was 18.1 weeks. In multivariate analysis, RT was the only independent prognostic variable for survival (HR: 9.1 [95% CI: 4.5-18.7]). Forty-two patients did not start RT mostly due to low KPS (<50). The median survival of the 43 patients who started RT was 45 weeks. In these patients, Cox multivariate analysis indicated that age was independently associated with prolonged survival (HR: 2.85 [95% CI 1.31-6.19]). Median survival of patients age 70 years and younger was 55 weeks compared with 34 weeks for patients older than 70 years.

CONCLUSIONS

The overall survival for elderly patients with MG is poor. RT seems to improve survival in patients up to 70 years, but in older patients treated with RT the survival is significantly shorter.

Phase I and pharmacokinetic study of preirradiation chemotherapy with BCNU, cisplatin, etoposide, and accelerated radiation therapy in patients with high-grade glioma

PURPOSE

We conducted a Phase I study of bischloroethylnitrosourea (BCNU), cisplatin, and oral etoposide administered prior to and during accelerated hyperfractionated radiation therapy in newly diagnosed high-grade glioma. Pharmacokinetic studies of oral etoposide were also done.

METHODS AND MATERIALS

Patients started chemotherapy after surgery but prior to definitive radiation therapy (160 cGy twice daily x 15 days; 4800 cGy total). Initial chemotherapy consisted of BCNU 40 mg/m2 days 1-3, cisplatin 30 mg/m2 days 1-3 and 29-31, and etoposide 50 mg orally days 1-14 and 29-42, repeated in 8 weeks concurrent with radiation therapy. BCNU 200 mg/m2 every 8 weeks x 4 cycles was given after radiation therapy.

RESULTS

Sixteen patients, 5 with grade 3 anaplastic astrocytoma and 11 with glioblastoma were studied. Grade 3-4 leukopenia (38%) and thrombocytopenia (31%) were dose-limiting. Other toxicities were anorexia (81%), nausea (94%), emesis (56%), alopecia (88%), and ototoxicity (38%). The maximum tolerated dose was BCNU 40 mg/m2 days 1-3, cisplatin 20 mg/m2 days 1-3 and 29-31, and oral etoposide 50 mg days 1-21 and 29-49 prior to radiation therapy and repeated in 8 weeks with the start of radiation therapy followed by BCNU 200 mg/m2 every 8 weeks for 4 cycles. Median time to progression and survival were 13 and 14 months respectively. Responses occurred in 2 of 9 (22%) patients with evaluable disease. In pharmacokinetic studies, all patients achieved plasma concentrations of >0.1 microg/ml etoposide (the in vitro radiosensitizing threshold), following a 50 mg oral dose. The mean +/- SD 2 hr and 6 hr plasma concentrations were 0.92 +/- 0.43 microg/ml and 0.36 +/- 0.12 microg/ml, respectively. Estimated duration of exposure to >0.1 microg/ml etoposide was 10-17 hr.

CONCLUSIONS

Preirradiation chemotherapy with BCNU, cisplatin, and oral etoposide with accelerated hyperfractionated radiation therapy in high-grade gliomas is feasible and merits further investigation. Sustained radiosensitizing concentrations can be achieved with low oral doses of etoposide.

[Concomitant chemoradiotherapy and malignant glial tumors in the adult]

The prognosis of adult patients with malignant gliomas remains poor despite advances in neurosurgery and radiotherapy. Even if chemotherapy has done little to improve on these results, except in the treatment of oligodendrogliomas, many authors have proposed to test the effect of radiotherapy by adding concomitant chemotherapy. Unfortunately, the analysis of these studies is difficult because all these protocols are different with a small number of patients. Furthermore, there are only a few studies evaluated in well controlled clinical trials with homogeneous patient population. Important factors such as tumor grade, patient age, and Karnofsky score, which have a strong influence on survival in malignant gliomas, are not clearly evaluated. Whatever, all these studies suggest that concomitant radio-chemotherapy seems not be promising in the treatment of malignant gliomas.

Technetium-99m sestamibi brain single-photon emission tomography for detection of recurrent gliomas after radiation therapy

Technetium-99m sestamibi (MIBI), an alternative radiopharmaceutical for myocardial perfusion imaging, has also been proposed for use as an imaging agent for various tumours, including breast cancer, lung cancer, lymphomas, melanomas and brain tumours. After routine radiation therapy, deteriorating clinical status or treatment failure may be due to either radiation-induced changes or recurrent tumour. Computed tomography and magnetic resonance imaging offer imperfect discrimination of tumour viability and radionecrosis. Against this background we undertook a retrospective study of 35 malignant glioma patients in whom clinical deterioration had occurred, in order to clarify the value of 99mTc-MIBI SPET in identifying tumour recurrence. SPET was performed 15 min after intravenous injection of 1110 MBq with a dual-headed gamma camera using a fan-beam collimator. Transverse, coronal and sagittal views were reconstructed. Intense MIBI uptake was found in 31 patients. This uptake was correlated with tumour recurrence as proved by histology and/or rapid, fatal evolution of these cases. The statistical analysis performed on this population of patients with MIBI uptake revealed a group of patients with a long mean survival and a group with a short mean survival. Two subgroups were found within each of these groups, according to the functional index ratio (tumour uptake/pituitary gland uptake ratio). No MIBI uptake was found in four patients who are still alive and can be considered to be disease-free. In those cases showing MIBI uptake, death occurred an average of 6.69 months following brain SPET. According to our results, the specificity and sensitivity of 99mTc-MIBI brain SPET seem to be high. Moreover, this technique is more accurate than computed tomography or magnetic resonance imaging for discriminating between tumour recurrence and radionecrosis.

X-ray-induced P-selectin localization to the lumen of tumor blood vessels

P-selectin is a cell adhesion molecule that is sequestered in Weibel-Palade storage reservoirs within the vascular endothelium and alpha granules in platelets. P-selectin is rapidly translocated to the vascular lumen after tissue injury to initiate the adhesion and activation of platelets and leukocytes. We studied the histological pattern of P-selectin expression in irradiated tumor blood vessels. We observed that P-selectin was localized within the endothelium of tumor vessels prior to treatment. At 1-6 h following irradiation, P-selectin was mobilized to the lumen of blood vessels. To determine whether radiation-induced vascular lumen localization of P-selectin was tumor type specific or species specific, we studied tumors in rats, C3H mice, C57BL6 mice, and nude mice. P-selectin localization to the vascular lumen was present in all tumors and all species studied. Irradiated intracranial gliomas showed P-selectin localization to the vascular lumen within 1 h, whereas blood vessels in normal brain showed no P-selectin staining in the endothelium and no localization to the irradiated vascular lumen. Radiation-induced P-selectin localization to the vascular lumen increased in time-dependent manner, until 24 h after irradiation. P-selectin in platelets may account for the time-dependent increase in staining within the vascular lumen after irradiation. We therefore used immunohistochemistry for platelet antigen GP-IIIa to differentiate between endothelial and platelet localization of P-selectin. We found that GP-IIIa staining was not present at 1 h after irradiation, but it increased at 6 and 24 h. P-selectin localization to the vascular lumen at 6-24 h was, in part, associated with platelet aggregation. These findings indicate that radiation-induced P-selectin staining in the vascular lumen of neoplasms is associated with aggregation of platelets. Radiation-induced localization of P-selectin to the vascular lumen is specific to the microvasculature of malignant gliomas and is not present in the blood vessels of the irradiated normal brain.

Gliomatosis cerebri: clinical features, treatment, and prognosis

To clarify clinical features and to elucidate prognostic factors and prognosis, the authors retrospectively analyzed 16 cases of gliomatosis cerebri treated at Seoul National University Hospital between January 1988 and December 1995. Age at diagnosis ranged from 19 to 62 (median 34) years and male to female ratio was 10:6. Most presented with headache or seizure, and the mean duration of symptoms was 12.8 months. A poorly defined diffuse high signal intensity lesion, extending in T2-weighted images for two lobes or more, was the characteristic magnetic resonance (MR) image finding. On postcontrast T1-weighted MR imaging, focal enhancement of the lesion was detected in five cases. All patients underwent histological confirmation by craniotomy (9 cases) or stereotactic biopsy (7 cases). Histologically, all patients had compatible findings of gliomatosis cerebri which are the widespread infiltration of neoplastic glial cells with minimal destruction of pre-existing structures. After histological diagnosis, external radiation therapy was begun except in one case, who declined this treatment. Fourteen patients completed the whole procedure and received the planned dose (mean 5780 cGy). Median survival time after diagnosis was 38.4 months. In univariate analysis, the Ki-67 labelling index (> 1) showed significant correlation with the length of survival (p = 0.006). It is suggested that 1) gliomatosis cerebri can be diagnosed by a combination of MR imaging findings and histological examination; 2) histological diagnosis and external radiation therapy might be a good treatment modality; 3) the Ki-67 labelling index correlates significantly with survival time.

[A clinical evaluation of combination therapy with radiation, MCNU, carboplatin and IFN-beta or with radiation, MCNU, carboplatin, etoposide and IFN-beta for malignant gliomas]

In this study, we examined the clinical course and prognosis of 32 patients with malignant glioma (17 patients with anaplastic astrocytoma, 15 patients with glioblastoma) treated with the MIC regimen (radiation, MCNU, carboplatin and IFN-beta) or MICE regimen (radiation, MCNU, carboplatin, etoposide and IFN-beta). Ten patients were treated with the MIC regimen and 22 patients with the MICE regimen. The patients treated with the MIC and MICE regimens exhibited no significant difference in clinical background factors. The response rate was 50.0% among the 8 evaluable patients treated with the MIC regimen, and 40.0% among the 20 evaluable patients treated with the MICE regimen. The first- and second-year survival rates for the MIC regimen were 40.0% and 30.0%, and those for the MICE regimen were 68.2% and 36.4%. The overall first- and second-year survivals were 59.4% and 33.9%, respectively. The 50% survival time was 8.6 months for the MIC regimen, 14.9 months for the MICE regimen, and 13.4 months overall. There was no significant difference in response rate or survival period between the group treated with the MIC regimen and that treated with the MICE regimen. Age, histological grade of malignancy, radicality of surgery and total dose of irradiation did not affect length of survival. The only factors significantly related to length of survival were response to the induction therapy and performance of maintenance therapy. These results did not demonstrate the superiority of either the MIC or MICE regimen to other regimens previously reported for the treatment of glioma. In addition, etoposide was found not to improve the efficacy of this type of combined chemoradiation therapy.

Selective radiosensitization of 9L glioma in the brain transduced with double suicide fusion gene

PURPOSE

Suicide gene therapy has proved to be successful in enhancing the therapeutic index by sensitizing genetically modified tumor cells to prodrugs. Two of the most widely studied suicide genes, herpes simplex virus type 1 thymidine kinase and Escherichia coli cytosine deaminase, have proved effective at selectively eliminating malignant tumor cells. We previously demonstrated that transduced 9L glioma cells expressing E. coli cytosine deaminase and herpes simplex virus type 1 thymidine kinase concomitantly as a fusion protein exhibited greater levels of targeted cytotoxicity and radiosensitization than could be achieved by single suicide gene therapy. The present in vivo studies were carried out to determine whether double suicide gene therapy would enhance the tumor control rate of orthotopically implanted malignant glioma growing in the brain when coupled with radiotherapy.

MATERIALS AND METHODS

Rat 9L gliosarcoma cells were transfected with retroviral vectors containing an E. coli cytosine deaminase and herpes simplex virus type 1 thymidine kinase fusion gene and maintained in Dulbecco's modified Eagle's medium. The antitumor response of 9L E. coli cytosine deaminase and herpes simplex virus type 1 thymidine kinase tumors growing in the brain of Fischer rats was evaluated with small tumors (6-day-old tumors) versus large tumors (14-day-old tumors) against single versus double prodrug treatments. In the large brain tumors, the therapeutic efficacy of the combined single and double prodrugs coupled with radiotherapy was evaluated.

RESULTS

Double suicide gene therapy using two prodrugs, 5-fluorocytosine (500 mg/kg) and ganciclovir (30 mg/kg), was effective in achieving long-term tumor control (50% survival) against early-stage brain tumors (6 days after implantation) but was only marginally effective against advanced stage tumors (14 days old). However, when these prodrugs were combined with radiotherapy and double suicide gene therapy against advanced-stage tumors, more than 70% of the animals were cured, whereas radiotherapy alone (20 Gy) failed to achieve any cure at all. Combined radiotherapy and single prodrug therapy showed a moderate increase in the animal survival rate (17% and 40% for 5-fluorocytosine and ganciclovir, respectively) but was inferior to the combination therapy of radiation and double prodrugs.

CONCLUSION

The present in vivo results indicate that double suicide gene therapy combined with radiotherapy may represent a new, effective approach to achieve a high tumor cure rate without producing any excessive normal tissue damage.

Epileptic seizures progressing into nonepileptic conversion seizures

BACKGROUND

Epileptic and nonepileptic seizures can occur in the same patient, but usually occur at different times. In 1885, Gowers suggested that minor seizures can elaborate into hysterical seizures, but the concurrence of epileptic and nonepileptic seizures is not well documented.

METHODS

We reviewed all patients with nonepileptic seizures documented with video-EEG recordings at our center to identify those with temporally associated epileptic seizures.

RESULTS

Four patients were identified in whom video-EEG-documented epileptic seizures were temporally associated with nonepileptic seizures. In one woman, the nonepileptic event followed an absence seizure. Given the high frequency of absence seizures, the occurrence of the nonepileptic seizure may have been coincidental. In three patients, the seizures were partial and arose from right frontotemporal regions. In these patients, epileptic seizures were infrequent.

CONCLUSIONS

Epileptic and nonepileptic seizures can be temporally related, and in patients with partial seizures, there may be a pathophysiologic relation in which ictal changes facilitate the development of conversion symptoms. Ictal activation or disinhibition of emotions or impulse control may contribute to these nonepileptic events.

Quality of life after radiation therapy of cerebral low-grade gliomas of the adult: results of a randomised phase III trial on dose response (EORTC trial 22844). EORTC Radiotherapy Co-operative Group

In 1985, the EORTC Radiotherapy Co-operative Group launched a randomised phase III study comparing high-dose (59.4 Gy in 6.5 weeks) versus low-dose (45 Gy in 5 weeks) radiotherapy with conventional techniques in patients diagnosed with low-grade cerebral glioma. The primary endpoint of the study was survival. No difference in survival was observed between the two treatment strategies. A quality of life (QoL) questionnaire consisting of 47 items assessing a range of physical, psychological, social, and symptom domains was included in the trial to measure the impact of treatment over time. Patients who received high-dose radiotherapy tended to report lower levels of functioning and more symptom burden following completion of radiotherapy. These group differences were statistically significant for fatigue/malaise and insomnia immediately after radiotherapy and in leisure time and emotional functioning at 7-15 months after randomisation. These findings suggest that for conventional radiotherapy for low-grade cerebral glioma, a schedule of 45 Gy in 5 weeks not only saves valuable resources, but also spares patients a prolonged treatment at no loss of clinical efficacy.

Evaluation of radiation effects against C6 glioma in combination with vaccinia virus-p53 gene therapy

The primary objective of this study was to evaluate the antitumor effects of recombinant vaccinia virus-p53 (rVV-p53) in combination with radiation therapy against the C6 rat glioma, a p53 deficient tumor that is relatively radioresistant. VV-LIVP, the parental virus (Lister strain), was used as a control. Localized treatment of subcutaneous C6 tumors in athymic mice with either rVV-p53 or VV-LIVP together with tumor irradiation resulted in low tumor incidence and significantly slower tumor progression compared to the agents given as single modalities. Assays of blood and spleen indicated that immune system activation may account, at least partly, for the enhance tumor inhibition seen with combined treatment. No overt signs of treatment-related toxicity were noted.

PCV chemotherapy for recurrent oligodendrogliomas and oligoastrocytomas

OBJECTIVE

The role of chemotherapy in the treatment of low-grade oligodendrogliomas and oligoastrocytomas is still unclear. A Phase II study was conducted to determine the benefits and toxicity of the procarbazine, lomustine, and vincristine (PCV) regimen in patients with low-grade oligodendrogliomas and oligoastrocytomas recurrent after surgery alone or surgery with radiotherapy.

METHODS

Patients with both enhancing and nonenhancing tumors were treated with up to six cycles of standard PCV, and response was evaluated by conventional criteria based on computed tomography or magnetic resonance imaging.

RESULTS

Sixteen of 26 patients (62%) responded to PCV: 3 (12%) experienced complete response, 13 (50%) experienced partial response, 8 (31%) had stable disease, and 2 (8%) had progressive disease. All symptomatic patients who responded and three with stable disease improved in seizure frequency, lateralizing signs, and symptoms of intracranial hypertension. The response rate for patients with enhancing lesions revealed by computed tomography or magnetic resonance imaging (74%) was significantly higher than that of patients with nonenhancing lesions (29%) (P < 0.05). Both oligodendrogliomas and oligoastrocytomas responded to PCV, with complete responses occurring in association with pure tumors only. The median time to tumor progression of all 26 patients was 24 months and was significantly longer for those with oligodendrogliomas compared with those with oligoastrocytomas (32 versus 12 mo) (P < 0.001). Chemotherapy was well tolerated, with mild hematological toxicity and rare skin rashes being the most frequent sequelae.

CONCLUSION

These results suggest that chemotherapy with PCV is effective in the treatment of recurrent low-grade oligodendrogliomas and oligoastrocytomas.

An opportunity for exploitation of research in biomedical engineering: the EC Life Sciences Demonstration Projects

To validate clinically a new stereotactic device for real-time monitored minimally-invasive brain surgery; to perform the first European phase I clinical trials of Boron Neutron Capture Therapy (BNCT) for treatment of glioblastoma, using the facility of the Community Joint Research Centre (JRC) in Petten, on forty patients from six different European centres. These are typical objectives of the current EC BIOMED 2 demonstration projects. The number of supported projects under BIOMED is now 16 in 1998, and will be in total around 80 for the three Life Sciences and Technologies Programmes. Demonstration is expected to play a major role in the Fifth Framework Programme, particularly in its so-called "Key Actions". This article addresses three of the main issues for potential applicants: the readiness for demonstration, the content of the consortium, and the dissemination strategy.

The results of radiotherapy for brainstem tumors

OBJECTIVE

This analysis was performed to examine the outcome of adult and pediatric patients with brainstem tumors.

METHODS AND MATERIALS

Forty patients with brainstem glioma were evaluated retrospectively. Included were 24 females and 16 males ranging in age from 3 to 81 years (median, 29.5 years). These patients were treated with various combinations of surgery, chemotherapy, and radiotherapy (RT). The length of follow-up in survivors ranged from 0.6 to 20 years (median: 3.2 years, mean: 6 years). Survival rates were calculated with the Kaplan Meier method and differences between survival curves were calculated using the log-rank test.

RESULTS

The overall 2 and 5-year survival rates were 44% and 34%, respectively. The median survival time was 19 months. The 5-year survival rate was 54% for patients with tumors outside the pons compared to 21% for those with tumors involving the pons (p = 0.04). The 5-year survival rate was 59% for patients with exophytic tumors as compared to 23% for those with intrinsic tumors (p = 0.05). Patients undergoing subtotal resection had a 5-year survival rate of 53% compared to 28% for those having only a biopsy or no surgical intervention (p = 0.04). None of the other potential prognostic or treatment related factors evaluated [patient age, tumor grade, tumor histology, radiotherapy parameters (including BID fractionation, 3-D treatment planning, or the use of doses > 55 Gy), or the administration of adjuvant chemotherapy] evaluated were associated with patient survival.

CONCLUSIONS

Brainstem gliomas generally occur in younger individuals. The survival rates were better for patients with exophytic tumors, those involving sites other than the pons, and tumors amenable to subtotal resection. Improvements in the outcome of patients with brainstem gliomas will require new therapeutic approaches.

Permanent I-125 brain stem implants in children

Between 1988 and 1997, 28 children have had iodine-125 implants for CNS tumors performed in our institution. Ten had stereotactic implantation in the brain stem region, and nine had the diagnosis of brain stem glioma (8 diffuse pontine, 1 midbrain tumor). Their ages ranged from 1.8 to 12 years. All patients had histological confirmation of malignancy (7 high-grade glioma, 2 low-grade glioma, 1 PNET). Diffuse pontine glioma patients received external beam radiation (50 Gy) followed by a fractionated stereotactic boost of 3 Gyx4 fractions. After 4-6 weeks, patients were reevaluated for stereotactic interstitial I-125 therapy. The planned implant dose was 82.9 Gy to the enhancing tumor (4 cGy per h). Preliminary results indicated that no surgical complications were associated with the catheter placement. Four patients have died (7-9 months from diagnosis) and four patients remain alive (5-38 months from diagnosis, median 10 months). Two autopsies confirmed the presence of progressive glioblastoma multiforme and intralesional necrosis. In one patient who received an implant alone for midbrain LGA, necrosis without tumor was found on biopsy after 36 months. He was successfully treated with hyperbaric oxygen therapy. The implementation of permanent I-125 implants appears to have a role in the management of pediatric CNS malignancy. This study confirms the results of previous reports regarding the safety of stereotactic interstitial brachytherapy in the brain stem. Tumor control for patients with high-grade brain stem glioma remains poor even with high focal radiation doses.

Hyperfractionated radiation therapy for incompletely resected supratentorial low-grade glioma. A phase II study

BACKGROUND AND PURPOSE

In order to investigate the feasibility, toxicity and antitumor efficacy of hyperfractionated radiation therapy, 37 adult patients with incompletely resected supratentorial low-grade glioma were entered into a phase II study.

MATERIALS AND METHODS

The radiation therapy dose was 55 Gy in 50 fractions in 25 treatment days over 5 weeks to the tumor plus a 2-cm margin, with an additional 17.6 Gy given in 16 fractions in 8 treatment days over 1.5 weeks to the tumor plus a 1.5 cm margin, using 1. Gy b.i.d. fractionation with a 6 h interfraction interval. The total tumor dose was 72.6 Gy in 66 fractions in 33 treatment days over 6.5 weeks.

RESULTS

The median survival time (MST) for all 37 patients has not yet been attained, while 5- and 7-year survival rates were 75% and 69%, respectively, The median time to tumor progression (MTP) has also not yet been attained, while 5- and 7-year progression-free survival (PFS) rates were both 70%. There was no difference in survival or PFS regarding histology, although patients with oligodendroglioma and mixed glioma had similar survival, both being higher than that of ordinary astrocytoma. On univariate analysis of potential prognostic factors, age, Karnofsky performance status (KPS), neurologic status and extent of surgery were found to influence survival. The toxicity of HFX RT was generally assessed as mild to moderate.

CONCLUSION

HFX RT is feasible with mild to moderate toxicity. Further studies are warranted with more patients and longer follow-up before testing it against standard fractionation RT in this patient population.

Diffuse brain stem gliomas. Are we improving outcome?

We reviewed our experience with diffuse brain stem glioma (dBSG) to evaluate whether any improvement of outcome had occurred in our patients over the years. Of the 24 children referred to our department with suspected dBSG from 1981 to 1997, 5 had a different final diagnosis based on the clinical course. Mean survival in the remainder was 16+/-9.8 months from diagnosis. Survival increased with a longer interval from onset of symptoms to diagnosis (12.9+/-9.0 months with an interval of 1-4 weeks; 19.50+/-10.8 months with a longer interval). Visual symptoms at presentation were associated with a poorer prognosis. Survival was better in the 3- to 5-year age group (at diagnosis). Overall, a trend toward a slight improvement in survival was seen over the years, which we presumptively attribute to the introduction of intensive chemotherapy for these patients. We suggest that chemotherapy may be important in the management of dBSG until a better modality is found.

Malignant glioma: who benefits from adjuvant chemotherapy?

We combined two randomized prospective Brain Tumor Study Group data sets to analyze the effects of prognostic factors on survival by treatment group. Adjuvant chemotherapy increased long-term survival regardless of prognostic factors. Pathological review revealed that oligo dendrogliomas were overrepresented among long-term survivors independent of therapy. Prognostic factors do not predict benefit from adjuvant nitrosourea in malignant gliomas, and long-term survival with chemotherapy is not explained by oligodendroglial tumors.

Long recovery times improve the detection of cellular resistance in vitro

In vitro cytotoxicity testing is used increasingly during the development of clinical treatment protocols. These tests are influenced by many variables, not all of which have been assessed systematically yet. We analyzed the influence of the recovery time between the end of treatments and measurements on the detection of cellular resistance. The development of resistance to cisplatin and radiation was chosen as a model since the schedule of these treatments is the objective of several ongoing clinical trials. C6 rat glioma, T98G, 86HG-39, A172 human glioma and TE671 human rhabdomyo-sarcoma cells were pretreated with radiation or cisplatin. The cellular resistance was then compared in pretreated and wild-type cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. In all cell lines, apparent drug concentrations killing 50% of the cells were dependent on the recovery time. In A172 cells this concentration was 10.3+/-02.1 microM after 48 h but decreased to 3.56+/-0.44 microM after 120 h recovery time (P < 0.001). After recovery times of more than 168 h, 53% of all pretreated cell lines were resistant to cisplatin or radiation, 25% were unchanged and 22% were more sensitive. However, only half the resistant cells could be identified when the MTT test was done with only 48 h recovery time. The sensitivity of detection increased from 0.46 to 0.83 when the recovery time of the test system was extended from 48 h to 168 h. The specificity was not dependent on the recovery time. Experiments showing resistance after short recovery times are reliable, but lack of resistance can only be shown in experiments with long recovery times. Cisplatin treatment can result in resistance to radiation in glioma cells.

Accelerated radiotherapy regimen for malignant gliomas using stereotactic concomitant boosts for dose escalation

The purpose of this pilot study was to determine the feasibility and toxicities of an accelerated treatment program by using a concomitant stereotactic radiotherapy boost given weekly during a course of standard external-beam irradiation (EBXRT) in patients with malignant gliomas. Twelve patients underwent biopsy or subtotal resection of a malignant glioma and were enrolled on the protocol, which delivered 44 Gy-EBXRT and a 12-Gy stereotactic radiotherapy boost given on 3 consecutive weeks of treatment for a total dose of 80 Gy over 33 days. Three patients with anaplastic astrocytoma and nine patients with glioblastoma multiforme had median survival times of 33 months and 16 months, respectively. All of the tumor recurrences were within or were closely adjacent to the region of high-dose irradiation. None of the patients required a treatment break, and there were no acute complications. Two patients developed seizures in the follow-up period, and four patients were diagnosed with radionecrosis at the time of the second operation. The treatment program was found to be feasible and was well tolerated, and it resulted in a rate of late complications similar to those of radiosurgery or interstitial brachytherapy.

11C-methionine and 18F-2-fluorodeoxyglucose positron emission tomography: a tool for diagnosis of cerebral glioma and monitoring after brachytherapy with 125I seeds

Forty-six patients with suspected brain tumors were investigated by positron emission tomography (PET). Using 11C-methionine PET, the spatial extent of increased uptake in gliomas was larger than that of contrast enhancement on CT/MR images in 67% or the same in 33%. Ten of 46 patients treated with brachytherapy for low-grade gliomas were also investigated with 18F-2-fluorodeoxyglucose (FDG)-PET. One year after seed implantation, the glucose metabolism had not changed, but the decline of methionine uptake was significant. In conclusion, 11C-methionine PET may improve tumor delineation and, following brachytherapy, provides more information on the therapeutic effects than FDG.

Synchronous radiochemotherapy in unfavorable brain tumors of children and young adults

The prognosis of patients with incompletely resected malignant brain tumors is almost fatal. In an attempt to improve the outcome of children and young adults with unfavorable brain tumors an intensive multimodal therapeutic strategy was developed combining simultaneous (hyper)fractionated external beam irradiation and conventional adjuvant chemotherapy after initial surgery. 17 patients aged between 2.10 and 25.11 years were entered into the study. 16/17 patients were treated according to the German/Austrian Pediatric Brain Tumor Study Group multicenter trial HIT '91. They are not protocol patients of this HIT '91 trial. Induction chemotherapy consisted of 2 courses of ifosfamide (3 g/m2/d) on days 1-3, etoposide (150 mg/m2/d) on days 4-6, methotrexate (5 g/m2) on days 15 and 22, cisplatin (40 mg/m2/d) and cytarabine (400 mg/m2/d) on days 29-31. Three weeks after the last dose of cisplatin/cytarabine the second course of chemotherapy was started. The last patient entered into the study received a modified therapy containing ifosfamide, cisplatin and etoposide. Synchronously at a median of 12 days after initiation of chemotherapy 12/17 patients received local radiotherapy (6000-7040 cGy) to the brain and 5/17 patients craniospinal irradiation (3520 cGy with a tumor boost of 1400-2000 cGy). 4-6 weeks after completion of the second course of chemotherapy maintenance therapy was started with carmustine (CCNU) (75 mg/m2) and carboplatin (400 mg/m2) each on day 1 and vincristine (1.5 mg/m2) on day 1, 8, 15. This course was repeated eight times every six weeks. 9/17 patients are alive at a median follow-up of 25 months (range 5-50) with 4 complete remissions, 2 partial remissions and 1 stable disease lasting 42+ months. Two patients, who initially had stable disease, progressed, but are still alive at 31+ and 41+ months after diagnosis. Median progression-free survival and median overall survival is 19 and 36 months, respectively. Hematologic and methotrexate-induced toxicity were severe and resulted in one therapy-related death. However, radiotherapy concomitant to chemotherapy appears to be an effective method of treatment for brain tumors with poor prognosis, though toxicity is severe in some cases.