Irradiation of primary brain-stem tumors

Radiotherapy for pediatric brain stem glioma: radiation dose, response, and survival

An analysis of 39 patients under 20 years of age with brain stem glioma treated with radiotherapy between 1977 and 1991 was undertaken. Twenty-eight (71.2%) of the patients responded well to initial radiotherapy, and 11 (28.8%) responded poorly. Median survival for the total patient population was 10 months. Response rates and median survivals were influenced by radiation dose: 45.5% and 9 months at doses less than 4499 cGy (n = 11), 83.3% and 13 months at doses between 4500 and 5499 cGy (n = 12), 66.7% and 11.5 months at doses between 5500 and 6499 cGy (n = 9), and 100% and 10 months at doses more than 6500 cGy (n = 7). Multivariate analysis revealed the response to initial radiotherapy was the only predictor of survival with radiation doses up to 6499 cGy. Four of the patients who responded well demonstrated radiological and/or histological calcification within or around the tumor at the time of clinical deterioration. Radiation injury was confirmed in two autopsy cases. The possibility that intratumoral radiation injury causes clinical deterioration is suggested.

Radiation therapy for brain stem tumor with special reference to CT feature and prognosis correlations

Seventy-nine patients with tumors of the medulla oblongata, pons, and midbrain treated by radiation therapy between 1962 and 1987 were analyzed. According to histology obtained in 28 cases, 61% were high-grade astrocytomas and 39% were low-grade astrocytomas. The 5- and 10-year survival rates of 71 patients who completed radiotherapy were 17 and 15%, respectively. Various potential prognostic factors were analyzed, and patients with a midbrain tumor, with a low-grade tumor, and without cranial nerve paresis were found to have a better prognosis. Computed tomography (CT) was performed both before and after radiotherapy on 42 patients. The volume of the tumor estimated from the CT image was various, but the tumors could be classified into three types according to the pattern of contrast enhancement (CE). Twenty-three tumors showed no CE, 15 showed a diffuse CE, and 4 showed a ring CE. No-CE tumors were generally hypodense on plain scan and were mostly large, whereas diffuse- or ring-CE tumors were relatively small. A complete response (CR) or partial response was obtained with 77% of the no-CE tumors, 64% of the diffuse-CE tumors, and 50% of the ring-CE tumors. The CR rate was higher in the tumors with a smaller volume. The 5-year survival rates for diffuse-CE, no-CE, and ring-CE tumors were 33, 15, and 0%, respectively. The 5-year survival rate was 56% for tumors smaller than 6 cm3, 16% for tumors between 6 and 20 cm3, and 0% for tumors larger than 20 cm3. In conclusion, (a) ring-CE tumors exhibited a poor prognosis; and (b) a diffuse-CE tumor, or a small or middle-sized no-CE tumor is most likely to be controlled by conventional radiation therapy.

Prognostic factors and results of therapy for adult thalamic and brainstem tumors

This report is a retrospective analysis of 83 adults (greater than 16 years of age) with histologically proven or presumed primary neoplasms of the thalamus, hypothalamus, midbrain, pons, and medulla. Patients were treated with combined surgery and postoperative irradiation or with irradiation alone at the Washington University Medical Center (St. Louis, MO) from January 1950 through December 1984. Histologic analysis confirmed the diagnosis of tumor in 21, including nine with well-differentiated astrocytoma, four with astrocytoma with anaplasia, and eight with glioblastoma multiforme. Overall and disease-free survivals at 5 years were 28.7 and 23.2%, respectively. A statistical analysis was performed to ascertain the prognostic importance of the following variables: age, race, gender, duration of symptoms, cranial nerve paresis, primary site, extent of surgery, histology, and irradiation dose. The only factor identified by univariate analysis to be critical for survival was primary location of disease. Patients with supratentorial (thalamus/hypothalamus, midbrain) tumors had a 10-year disease-free survival of 15.4% compared to 29.6% for those with infratentorial (pons, medulla) tumors (P = 0.07). Patients with lesions of the pons had a 5-year disease-free survival of 35.8% compared to 13.8% for those with tumors of the thalamus (P = 0.05). Increasing irradiation dose was not correlated with superior survival. Factors evaluated but established to be insignificant were age (P = 0.27), race (P = 0.63), gender (P = 0.27), duration of symptoms (P = 0.19), cranial nerve paresis (P = 0.71), histologic type (P = 0.16), and extent of surgery (P = 0.94). Follow-up for 13 surviving patients ranged from 2.6 to 28.7 (mean, 12.0) years. Neurologic deficits in surviving patients were absent in 15% (two of 13), mild in 62% (eight of 23), and moderate in 23% (three of 13). One case of brain radionecrosis was identified (6000 cGy, 200 cGy daily).

Multivariate analysis of prognostic factors in pediatric and adult thalamic and brainstem tumors

A multivariate analysis of prognostic variables was performed on a retrospective review of 136 patients with presumed or histologically proven primary lesions of the thalamus and brainstem treated by combined surgery and post-operative irradiation or by irradiation alone from January 1950 through December 1983. Overall survival for all patients at 5 and 10 years was 34.4 and 27.8%, respectively. Follow-up of 33 living patients ranged from 3 to 22 years. Prognostic variables analyzed by univariate analysis and found to be of significance (p less than 0.05) were race, duration of symptoms, extent of surgery (i.e. subtotal excision), and dose of irradiation. Further evaluation by Cox regression analysis revealed these same factors to be of prognostic significance (p less than 0.05). It is of importance to note that age and tumor site were not significant prognostic variables in the multivariate analysis but were significant by univariate analysis. The 5-year overall survival for patients with thalamic tumors was 59.5 and 20.9% for children and adults, respectively (p = 0.006). The 5-year overall survival for patients with pontine lesions was 46.6 and 16.0% for adults and children, respectively (p = 0.01). Only one patient was known to have expired due to a complication of therapy. Neurologic deficits and functional ability was normal or mild in 57.6% of the surviving patients.

Undifferentiated gliomas of the brain stem

Undifferentiated gliomas of the brain stem were confirmed surgically in two young children. The patients were treated by aggressive irradiation of the entire neuraxis, similar to that administered for medulloblastoma. Therapy resulted in a good prognosis and there was no tumor recurrence.

Irradiation of primary thalamic and brainstem tumors in a pediatric population. A 33-year experience

A retrospective analysis of 70 pediatric patients (less than 16 years of age) with histologically proven or presumed primary neoplasms of the thalamus, hypothalamus, and brainstem, treated with combined surgery and postoperative radiotherapy or radiotherapy alone at the Washington University Medical Center from January 1950 through December 1983, is reported. Overall survival for all patients at 5 and 10 years was 34.9% and 32.7%, respectively. Follow-up of the 22 surviving patients ranged from 3.0 to 20.0 years (median, 10.6 years). Statistical analysis of multiple prognostic factors was performed. Prognostic factors found by single variate analysis to significantly influence survival were primary site of disease, extent of surgery, race, cranial nerve paresis at diagnosis, and dose of radiation. Factors evaluated but found to be insignificant were age at diagnosis, duration of symptoms before diagnosis, sex, and volume irradiated. Multivariate analysis revealed that only total radiation dose and race were of prognostic significance.

Cystic schwannoma of the trochlear nerve mimicking a brain-stem tumor. Case report

A case is reported of a rare cystic schwannoma of the fourth cranial nerve which was interpreted as a probable intrinsic brain-stem lesion. The clinical approach to brain-stem tumors in terms of empirical treatment or surgical biopsy is discussed.

Brain-stem tumors in childhood: a prospective randomized trial of irradiation with and without adjuvant CCNU, VCR, and prednisone. A report of the Childrens Cancer Study Group

Seventy-four children with a brain-stem tumor diagnosed between 1977 and 1980 were entered into a prospective study in which exploration and assessment for resection were optional, radiation treatment using standard methods was required, and randomization occurred with regard to the use of adjuvant chemotherapy (1-(2-chloroethyl)-1-nitrosourea, vincristine, and prednisone) or no further treatment. The overall 5-year survival rate was 20% and was not improved by the adjuvant chemotherapy program. An increased risk of infection was associated with the adjuvant therapy.

Brainstem glioma: an analysis of 85 cases

The study analyses 85 cases of brainstem glioma in the past 35 years, 69 of which include patients under 16 years of age. The incidence of brainstem glioma was 2.4% of all intracranial tumours, and 9.4% of intracranial tumours in children. There were two peaks in age distribution, in the first and in the fourth decades. In children, the tumours were located mainly in the pons, so VIth and VIIth cranial nerve palsies, and pyramidal and cerebellar signs were frequently seen. In adult cases, the tumours ranged in location from the midbrain to the medulla, so neurological symptoms caused by lesions of the whole brainstem axis were seen. The left side was dominant in both age groups. The choice of treatment was steroid administration and radiation. Chemotherapy was not effective. Even after these treatments, the median survival period from onset was no longer than 10.5 months. We conclude that the treatment of brainstem gliomas in children should be distinguished from adult cases, which in the latter may be considered to be merely one of the gliomas which may occur at any other sites. Since brainstem gliomas in children may be congenital, we must redirect our treatment of these lesions to treatment of congenital tumours.

Long-term results of surgically treated brainstem gliomas

Long-term results of 16 surgically treated brainstem gliomas are reported. The results have been reviewed with reference to the clinical and pathological criteria defined by Hoffman and co-workers (1980) in the attempt to differentiate a distinct group of benign tumours. A good correlation has been obtained. The usefulness of surgical treatment of brainstem gliomas has been stressed in view of the survival time as well quality of survival.

Primary brain stem tumours

The material consisted of 31 patients with primary brain stem tumours who were investigated retrospectively. Twenty patients were younger than 16 years of age (range: 1 1/2-65 years). The mean age was 11 years. The female/male sex ratio was 19/12. Histological diagnoses were available for 18 patients. All of the verified tumours were gliomas. The diagnoses in 12 cases were made by section or biopsy; in 15 by standard clinical and radiological examinations and in 4 by exploratory operations. Headaches, mental changes, speech and gait disturbances were the most common symptoms at the onset of the illness and at the time of diagnosis. The mean latency period between the emergence of symptom(s) until diagnosis was 4 months (range: 1/2-48 months). Amongst the dominant objective findings were failure of the V, VI and VII cranial nerves, pyramidal tract symptoms, ataxia and nystagmus, occurring singly or in combination. Pneumoencephalograms disclosed characteristic changes in 25 patients (83%). Fourteen patients (45%) received radiation treatment, from which 5 (36%) obtained a temporary remission in their symptoms. The postdiagnostic mean survival period for the patients was 15 months (range: 0-92 months). The survival time was found to depend on the number of damaged cranial nerve nuclei at the time of diagnosis and on the degree of severity and duration of the accompanying hydrocephalus. The prognosis was unfavourable, as the percentage of patients who survived for 2 years was only 6%, and a total duration of illness longer than 2 years occurred in only 7 patients. None of the patients were still surviving at the conclusion of this investigation.

Infratentorial glioblastoma: the role of neuraxis irradiation

The patterns of clinical-and autopsy-documented tumor spread were evaluated for 15 patients with biopsy-proven infratentorial (8 cerebellar, 2 brainstem, 5 intramedullary spinal cord) glioblastoma. No patient developed clinical nor autopsy evidence of subarachnoid dissemination, even though no patient had received craniospinal axis irradiation. Fully 14 of the 21 previously reported patients with subarachnoid dissemination from infratentorial glioblastoma had this diagnosis made only at autopsy. The overall poor prognosis at present (8% 3-year survival from the present series and recent literature) along with the demonstrated pattern of local-regional aggressiveness as the major form of initial spread and post-irradiation recurrence, suggests that routine craniospinal axis irradiation may not be indicated for most patients with infratentorial glioblastoma.