Akira Zama

Three-dimensional observations on microvascular growth in rat glioma using a vascular casting method

SummaryThe microvascular growth of ethylni-trosourea-induced rat glioma was observed using vascular casting and scanning electron microscopy (SEM). Light microscopy showed central necrosis and marginal invasive tumor cell growth with increased vascularity, and suggested that adopted pre-existing circulation was dominant in the inoculated brain tumors. In SEM, numerous buds or nodular protrusions and a few large and tortuous vessels along the tumor margin were seen at the early stage. In the intermediate stage, microaneurysms, buds with septum formation and anastomotic arches appeared, and these tumor vessels became more tortuous and larger, and extended as the tumor grew. Several “potato-shaped” huge vessels and linear nodular large vessels also appeared. In the late stage, glomeruli appeared and potato-shaped huge vessels increased in number. The neovascularization and microvascular growth of the tumors was characterized by three patterns: (a) growth of the parent vessels forming buds, (b) vascular growth in a meshwork formation producing glomeruli, and (c) vascular enlargement without a definite pattern creating potato-shaped huge vessels. The tumor vessels gradually lost their natural three-dimensional structure.

Management of recurrent pilocytic astrocytoma with leptomeningeal dissemination in childhood

Abstract Two cases of recurrent pilocytic astrocytoma with leptomeningeal dissemination (LMD) are described. A 6-year-old boy presented with a cerebellar tumor, which was subtotally removed. Tumor recurrence with LMD occurred 4 years later. Reoperation for tumor removal followed by craniospinal irradiation stabilized the LMD over 5 years. A 4-year-old girl presented with a chiasmatic-hypothalamic tumor. Partial removal of the tumor was followed by radiation therapy. Tumor regrowth with LMD occurred 4 years later and was managed by reoperation, chemotherapy and radiotherapy. Tumor recurrence with LMD can be stabilized by multimodal treatment without tumor progression.

Diagnosis of germinal neoplasm in the thalamus and basal ganglia

Germinal neoplasms originating in the thalamus and basal ganglia were histologically verified by stereotactic biopsies in five cases and by other methods in three cases. Immunoperoxidase staining was performed on the tumors using antibodies against human chorionic gonadotropin and placental alkaline phosphatase. The presence of human chorionic gonadotropin was demonstrated in one germinoma and two mixed tumors, but not in three germinomas. Placental alkaline phosphatase was demonstrated to be present in four germinomas and one mixed tumor. Stereotactic biopsy specimens can be studied immunohistochemically, and the placental isoenzyme of alkaline phosphatase appears to be a new tumor marker for germinoma.

Gamma Knife Radiosurgery for Acoustic Schwannoma: Effects of Low Radiation Dose and Functional Prognosis

The effects of relatively low dose Gamma Knife irradiation on acoustic schwannoma were evaluated in 29 patients followed over 2 years after treatment. The mean dose delivered to the tumor periphery was 12.1 Gy. Lowering of the magnetic resonance signal intensity in the tumor center appeared in 69% and signs of tumor shrinkage appeared in 59% of cases. The cyst in the tumor enlarged in 3 cases, and 2 cases developed hydrocephalus. The percentage of pure-tone hearing preservation was 82% at 3 months, 73% at 6 months, 68% at 12 months. 64% at 18 months and 59% at 24 months in 22 out of 29 cases. Relatively low dose Gamma Knife radiosurgery was effective in suppressing tumor growth, with preservation of hearing.

Large dose fraction radiotherapy in the treatment of glioblastoma

SummaryTwenty-four adults with glioblastoma multiforme (astrocytoma, grade 4) underwent postoperative large dose fraction radiotherapy (LDFR; 5 Gy twice weekly) with Linac X-rays. The outcome in this group was compared with that of 26 patients who received conventional fractionated radiotherapy (CFR; 2 Gy 5 times weekly). The time, dose, and fractionation (TDF) factor was about 100 in both groups. The survival rates following LDFR and CFR were, respectively, 63% vs 65% at 1 year; 36% vs 8% at 2 years; 17% vs 4% at 3 years; and 4% vs 0% at 5 years. Although the survival curve for LDFR was superior to that for CFR, the difference was not statistically significant. Autopsies of nine LDFR and 13 CFR patients showed no residual tumor in one case and no cases, respectively; small residual tumor in three cases in each group; extensive coagulation necrosis of the tumor and surrounding brain tissue in one LDFR and four CFR patients; tumor proliferation in three LDFR and four CFR cases; and mixed glioblastoma and fibrosarcoma in one LDFR and two CFR patients. These results suggest that maximum tumor removal followed by LDFR may offer a better prognosis for patients with glioblastoma than that offered by surgery plus CFR.

A suprasellar embryonal carcinoma producing alpha-fetoprotein and human chorionic gonadotropin; treated with combined chemotherapy followed by radiotherapy

A case of primary suprasellar embryonal carcinoma that produced alpha-fetoprotein and human chorionic gonadotropin in a 12-year-old girl is reported. Partial removal of the tumor and cis-platinum-based combined chemotherapy followed by local radiotherapy resulted in a definite regression of the tumor and improvement from clinical signs and symptoms. After these treatments, the concentrations of alpha-fetoprotein and human chorionic gonadotropin in both serum and cerebrospinal fluid decreased to undetectable levels. Serum basic fetoprotein, another tumor marker, can be a tool for evaluating the clinical course following postoperative chemotherapy.

Suprasellar germinomas; relationship between tumour size and diabetes insipidus.

SummaryThe clinical and neuro-endocrinological aspects of 17 suprasellar germinoma patients treated between 1972–1991 are reported. Surgical extirpation was not initially attempted, but all patients received irradiation with or without a biopsy. Sixteen of those have led useful lives with appropriate hormonal replacement therapy during a mean follow up of 8 years.Seven tumours at diagnosis were less than 2 cm in diameter (type 1), nine tumours more than 2 cm (type 2), and one double midline tumour was of unknown size. All 7 type 1 patients required 1-deamino-8-D-arginine-vasopressin (DDAVP) to control diabetes insipidus (DI), but only 2 of the 9 type 2 patients have needed DDAVP since completion of the treatment. Patients with smaller tumours required more DDAVP following tumour disappearance, than those with larger tumours. The prognostic indicators for the post-treatment course of DI and retarded growth appeared to be the tumour size and the age at diagnosis.We also emphasize the absence of metastasis in unoperated cases and the use of tumour markers as a diagnostic criterion which obviates surgical acquisition of tissue to make the diagnosis. Possible reasons are discussed and the literature reviewed.

A comparison of children with suprasellar germ cell tumors and craniopharyngiomas: Final height, weight, endocrine, and visual sequelae after treatment

BACKGROUND Although treatment results of craniopharyngiomas and germ cell tumors in children have been reported extensively, the relationship between various posttreatment sequelae and the nature of the tumor is not well understood. METHODS From 1968-94, 47 children with 23 suprasellar germ cell tumors and 24 craniopharyngiomas were treated at Gunma University Hospital, Japan. Forty survivors were assessed with regard to Karnofsky scores, visual scores, final height, final weight, and other endocrine sequelae as long-term functional prognostic indicators. RESULTS Kaplan-Meier life-table estimates and Karnofsky scores were not significantly different between the two histologic groups. The visual function of survivors did not differ significantly at diagnosis. However, the final visual function following treatment in the germ cell tumor group was better than in the craniopharyngioma group (p < 0.05). Antidiuretic hormone secretion was significantly impaired at diagnosis in the germ cell tumor group (p < 0.0001). However, there was only a marginally significant difference in posttreatment persistent diabetes insipidus. Craniopharyngioma children were shorter and more obese at diagnosis (p < 0.02), and became much more obese than germinoma children with the same hormone therapy (p < 0.003), although the height difference became insignificant following growth hormone treatment. CONCLUSIONS Children with craniopharyngiomas tended to have more visual disturbances, increased dwarfism and obesity, and less diabetes insipidus than patients with germ cell tumors despite adequate therapy. The method of quantifying visual function may in itself be useful.

Radiobiological Effects of Gamma Knife Radiosurgery on Brain Tumors Studied in Autopsy and Surgical Specimens

To elucidate the radiobiological effect of Gamma Knife radiosurgery on brain tumors, we performed a histological study on nine cases. In two, the material was obtained at autopsy and in seven following surgery. In the central region of the radiation field, destructive changes occurred both in tumor cells and in vessels. In the peripheral area, destructive and proliferative vascular changes were intermingled with residual tumor tissue. Immunohistochemical staining of surgical specimens showed that the vascular proliferative changes consisted of pericytic proliferation with or without endothelial proliferation. These characteristic changes might suppress tumor growth, at least in the short-term.

Assessment of malignancy of glioma by positron emission tomography with 18F-fluorodeoxyglucose and single photon emission computed tomography with thallium-201 chloride

Abstract The histological diagnosis and proliferative potential measured by bromodeoxyuridine (BrdU) labelling index (LI) were corelated with preoperative CT and contrast-enhanced, MRI, 18F-flurodeoxyglucose positron emission tomography (PET) and 201T1 single photon emission computed tomography (SPECT) in 43 patients with various grades of glioma. 201T1 SPECT had slightly higher sensitivity to tumours with BrdU LI N 5 % (showing 10/10) than 18F-FDG PET (7/8 tumours). 18F-FDG PET was better for identifying tumours of BrdU LI < 1 % (13/15) than 201T1 SPECT (13/22). Accumulation of 201T1 in the tumour was slightly different from contrast enhancement on CT and/or MRI, and gave “false-postive” results in some low-grade gliomas. However, 201T1 SPECT, which is available in many hospitals and may cost less, provided useful information to supplement that from CT and MRI.